Skip Navigation LinksHome > May 2010 - Volume 69 - Issue 5 > American Association of Neuropathologists, Inc.: Abstracts o...
Text sizing:
A
A
A
Journal of Neuropathology & Experimental Neurology:
doi: 10.1097/NEN.0b013e3181deb5a1
Abstracts

American Association of Neuropathologists, Inc.: Abstracts of the 86th Annual Meeting June 10-13, 2010 Philadelphia, PA

Free Access
Back to Top | Article Outline

PLATFORM SESSION 1: TUMORS - GLIAL

1 Notch3 Activation Promotes Site-Specific Invasive Glioma Formation

Charles Eberhart1, Tarran Pierfelice2, Karisa Schreck2, Louis Dang2, Nicholas Gaiano2. 1Johns Hopkins University School of Medicine; 2Johns Hopkins University

While Notch signaling has been widely implicated in tumor growth, direct evidence for in vivo initiation of neoplasia by the pathway is limited. To examine tumorigenic potential of Notch signaling in the brain, we injected retrovirus encoding activated forms of the Notch1, 2 and 3 receptors into the ventricles of embryonic day 9.5 mice under ultrasound guidance. Proliferative lesions expressing GFAP and nestin were identified in the retina and optic nerve in the majority of animals injected with constitutively active Notch3. The tumor cells appeared bland, with fibrillar cytoplasm, but they contained mitotic figures and invaded extensively into periocular tissues. Activated Notch3 was approximately ten-fold more efficient in inducing glial tumors in the retina and optic nerve than Notch1 or Notch2. Because human optic nerve gliomas are predominantly pilocytic, we examined Notch3 levels in a number of Grade I astrocytomas. Overexpression of Notch3 mRNA was identified in 2 of 3 human optic pathway pathway gliomas, and in 7 of 19 pilocytic astrocytoma arising at other sites. While signs of Notch activation have been documented in human malignant gliomas, in our model introduction of active Notch receptors into the brain never induced glial tumors - a distinct contrast with findings in the optic nerve and eye. Our results demonstrate the ability of Notch3 to efficiently induce gliomas in the optic nerve and eye, highlighting the distinct potentials of Notch receptor paralogs with respect to tumor initiation. They also suggest that glial precursors optic nerve, but not the brain, are susceptible to transformation by Notch3.

Back to Top | Article Outline
2 Knock Down of HIF-1alpha in Glioma Cells Reduces Invasion and Impairs Tumor Sphere Formation

David Zagzag1, Olga Méndez2, Jiri Zavadil2, Yevgeniy Lukyanov2, Daniel Santovasi2, Shu-Chi Wang2, Elizabeth Newcomb2. 1Department of Pathology and Neurological Surgery, NYU; 2Department of Pathology, New York University

Glioblastoma (GBM) is the most common and the most malignant primary intracranial human neoplasm. GBMs are characterized by the presence of extensive areas of necrosis and hypoxia. Hypoxia and its master regulator, hypoxia inducible factor 1 (HIF-1) play a key role in glioma invasion. To further elucidate the functional role of HIF-1alpha in glioma cell migration in vitro and in invasion in vivo, we used a shRNA approach to knock down HIF-1alpha expression complemented with genome-wide expression profiling, performed in both normoxic and hypoxic conditions. Our data show that knock down of HIF-1alpha in human and murine glioma cells significantly impairs their migration in vitro as well as their ability to invade into the brain parenchyma in vivo. Next, we assessed the role that HIF-1alpha plays in maintaining the characteristics of glioma stem cells (GSCs). By using the tumor sphere forming assay, we demonstrate that HIF-1alpha plays a role in the survival and self-renewal potential of GSCs. Finally, our expression profiling experiments in glioma cells provide a detailed insight into a broad range of specific biological pathways and processes downstream of HIF-1alpha.

Back to Top | Article Outline
3 Expression and Activation of CSF1R and its Ligands in High Grade Astrocytoma

Fausto Rodriguez1, Aaron Bender1, Gobinda Sarkar1, Lara Collier2, Bridget Hoesley1, Mark Schroeder1, Jann Sarkaria1, David Largaespada3, Robert Jenkins1. 1Mayo Clinic College of Medicine; 2University of Wisconsin-Madison; 3University of Minnesota

Prior forward genetic studies using the Sleeping Beauty transposon system have uncovered Csf1 as a frequent insertional mutagenesis target in murine high grade astrocytomas. CSF1 is a cytokine that has been proven to play an essential role in the growth of hematopoietic cells by activating its receptor CSF1R. The two known ligands for CSF1R are CSF1 and the recently discovered IL34. The precise role of CSF1 protein and its receptor CSF1R in human high grade astrocytomas is unclear. We evaluated the protein expression levels of CSF1R (total), its two known ligands CSF1 and IL34, as well as its activation status using anti pCSF1RY809 and pCSF1RY723 antibodies by immunohistochemistry. Two different tissue microarrays of human high grade astrocytomas were stained. The strongest expression (3+) was observed for CSF1 (n = 43,62%) and total CSF1R (n = 49,70%) in tumor cells. In contrast, IL34 showed absent to weak staining in most cases (n = 40,60%). pCSF1RY809 and pCSF1RY723 were weak to negative in 90%. To evaluate the expression of these antigens with respect to regional heterogeneity, we also stained 11 orthotopic (intracranial) GBM xenografts. Moderate (2+) to marked (+3) expression of CSF1 was present in 64% of xenografts, CSF1R in 80%, and IL34 in 0%. Antibodies reflecting CSF1R activation (pCSF1RY809 and pCSF1RY723) were positive in 72 and 80% respectively, and interestingly, staining for these antibodies was accentuated at the interface with non-neoplastic murine brain. In summary, CSF1 is frequently expressed in human high grade astrocytomas and human GBM xenografts, and is probably the predominant ligand for CSF1R. Although CSF1R is frequently expressed in high grade astrocytomas, its activation may be selective, and depend on the tumor microenvironment.

Back to Top | Article Outline
4 Comprehensive Molecular Analysis of Oligodendroglial Tumors. Merging Genomic, Transcriptomic and Metabolomic Data

Gustavo Sevlever1, Ruben Ferrer-Luna2, Lina Nuñez3, Jorge Calvar4, Bernardo Celda5, Horacio Martinetto3. 1FLENI; 2Department of Physical-Chemistry. Universitat de Valencia. Spain; 3FLENI-Neuropathology Department; 4Neuroradiology Service. FLENI. Buenos Aires. Argentina.; 5Universitat de Valencia (UVEG)-Valencia, Spain

The challenge in post-genomic era is to integrate genomic, transcriptomic, proteomic and metabolomic data. It has been observed that Oligodendrogliomas (OT) are chemosensitive solid tumors. Loss of chromosome (LOH) 1p was associated with chemotherapy response. The purpose of this study was to obtain a comprehensive genomic analysis of DNA copy number, gene expression, DNA methylation, and "ex vivo" and "in vivo" metabolic profiles in 29 OT patients. Affymetrix SNP and expression arrays were used. EGFR, CDKN2A and 1p, 19q, 10q status were evaluated by Real Time PCR analysis. TP53 and IDH1 mutations were confirmed by sequencing. Genes more differentially expressed were selected and evaluated by PCA, Hierarchical_Clustering and Functional_Enrichment was determined. Methylation status was assessed by base specific cleavage and mass spectrometry. NMR metabolic profiles were performed according to eTUMOUR protocols. Three OT groups were detected. "Proneural" group, with samples showing 1p/19q LOH, over-expressed genes related to neurogenesis, showed MGMT hipermethylation and IDH1 mutation; this group had good overall survival. Tumors harboring 1p/19q ROH over-expressed genes linked to immune response and proliferation. This group could be further divided in two subtypes, "Intermediate" which did not show major genetic aberrations other than LOH and mutation at TP53, IDH1 mutation and GSTP1 hypermethylation in most samples. "Proliferative" group concentrated samples carrying several anomalies: LOH at 10q, EGFR amplifications, MGMT and GSTP1 hypomethylation; worst prognosis and GBM features were displayed. CDKN2A was inactive in all samples; hypermetilation was more frequent in indolent tumor and deletion was higher in proliferative group. OT with worst prognosis presented increased levels of Phosphocholine, Choline, Fatty acids and Alanine. In the same way OT harboring 1p/19q ROH present higher glutathione levels. Each tumor is singular but detected alterations could reveal the divergent response showed by these molecular subgroups in survival and chemotherapy treatment.

Back to Top | Article Outline
5 A Useful Panel to Differentiate Astrocytoma From Astrocytosis

Sandra Camelo-Piragua1, Michael Jansen2, Aniruddha Ganguly1, J. ChulMin Kim2, Arjola Cosper1, Dora Dias-Santagata1, John Iafrate1, Catherine Nutt2, David Louis1. 1Department of Pathology, Massachusetts General Hospital; 2Center for Cancer Research, Massachusetts General Hospital

One of the major challenges of surgical neuropathology is the distinction of diffuse astrocytomas from astrocytosis. Currently, the most used ancillary tool to solve this problem is p53 immunohistochemistry. However, p53 is not sensitive or specific. Recently, isocitrate dehydrogenase 1 (IDH1) mutations have been found more commonly in lower grade gliomas and secondary glioblastomas. Most IDH1 mutations are due to a specific amino acid change from arginine to histidine at codon 132 (R132H). In this study we developed a panel of ancillary studies to differentiate astrocytomas from astrocytosis. We studied surgical biopsy specimens from 21 WHO grade II diffuse astrocytoma and 20 reactive conditions. Our panel included immunohistochemistry for R132H mutant IDH1 and p53; mutation analysis for IHD1 and FISH for gain of chromosome 7. R132H mutant IDH1 immunohistochemistry was positive in 10/21 (47.6%) astrocytomas and absent in 100% of astrocytosis. IDH1 mutation analysis identified all immunoreactive cases for R132H and four additional cases with other mutations (three R132C and one R132G). p53 immunohistochemistry was found in 10/21 (47.6%) astrocytomas and none of the astrocytosis. Five tumors showed co-expression of mutant IDH1 and p53. Of the case analyzed, twelve low grade gliomas showed gained of chromosome 7 by FISH analysis and complete results will be presented. This diagnostic panel identified tumor in 19/21 (90.5%) cases. We therefore demonstrate that when used together this panel increases significantly the tumor detection rate in biopsy specimens.

Back to Top | Article Outline
6 A Genetically-Defined, Orthotopic Allograft Model System of Glioblastoma: Pathological Features and Experimental Therapeutics

C. Miller, Ryan Bash, Mark Vitucci, Kristen White. University of North Carolina

Existing preclinical mouse models of glioblastoma (GBM) do not accurately recapitulate the genetics and biology of human GBM and are poorly predictive of drug efficacy in patients. We have developed an orthotopic allograft model of GBM in immunocompetent, syngeneic mice using AdCre-infected primary astrocytes from a conditional genetically-engineered mouse (GEM) (TRP-/-) with inactivated RB and PTEN and constitutively activated KRAS (KRASG12D), common genetic lesions identified in a large fraction of human GBM. Unlike orthotopic xenografts of established human GBM cells in immunodeficient mice, TRP-/- allografts reproducibly (10 experiments, N = 92, median survival (MS) 22 d, 95% CI 21-23 d) grow rapidly (2 d doubling time by MRI) as diffusely infiltrative masses with extensive secondary structures of Scherer. Comparative genomics by unsupervised hierarchical clustering with gene expression profiles of human GBM from TCGA showed that untreated TRP-/- allografts were most similar to proneural (PN) human GBM. To validate this model system, the efficacy of TMZ (100 mg/kg qd d 6-10), B20-4.1.1 (a murine bevacizumab equivalent, 5 mg/kg biweekly x3), or XRT (5 Gy fractions qod d 6-10) on established TRP-/-allografts was defined. TMZ alone was ineffective (22 d MS, log-rank P = 0.16), likely due to the elevated MGMT expression found in these tumors. B20-4.1.1 was effective (MS 28 d, P = 0.01), but fractionated XRT was superior (34 d MS, P = 0.0001 vs. sham, P = 0.003 vs. B20-4.1.1). We established a genetically tractable model system uniquely suited for investigation of the genetic basis of gliomagenesis, particularly the invasive phenotype, and for preclinical drug development. Qualitatively similar responses of PN TRP allografts and human GBM to standard-of-care (SOC) therapeis suggest that this model system will serve as a facile platform for biomarker development to further stratify human PN GBM for SOC versus alternative therapies.

Back to Top | Article Outline
7 Pharmacological Manipulation of the PI3 Kinase Pathway in a Genetically-Defined, PTEN-Deficient Model of Glioblastoma

Mark Vitucci, Ryan Bash, Kristen White, C. Miller. University of North Carolina

Glioblastoma (GBM) is a lethal, high-grade, diffuse glioma that remains treatment-refractory. PI3 kinase (PI3K) pathway genes (PIK3CA, PTEN, AKT1) are altered in 50% of GBM and numerous drugs that target this pathway are being investigated in clinical trials. Prospective identification of PI3K pathway abnormalities may permit molecular stratification and individualized drug selection for GBM patients. We developed a PTEN-deficient genetically-engineered mouse model (GEMM) of glioblastoma by infecting primary astrocytes from a conditional GEM (TRP-/-) with adenoviral-Cre, resulting in inactivated RB and PTEN and constitutively activated KRAS (KRASG12D). Cultured TRP-/- tumor cells were treated with PI3K pathway inhibitors targeting PI3KCA (LY294002), mTOR (rapamycin), and both PI3KCA and mTOR (PI-103). Proliferation in vitro was determined by MTS. Kinetics of phosphorylated PI3K pathway protein (AKT, MTOR, S6 ribosomal protein (S6RP), 4EBP1) expression was determined by quantitative immunoblots. Pathway-specific mRNA expression profiles will be determined by significance analysis of microarrays on cells ± drugs and hierarchical clustering and compared to human GBM data from the TCGA project. TRP-/- tumor cells are relatively insensitive to anti-proliferative effects of PI3K pathway inhibition (IC50 2-40 µM). However, continuous exposure to each drug inhibits PI3K signaling flux (pS6RP and to a lesser extent pAKT levels) 80-90% with maximum inhibition at 2 to 4h and continuing for 24-72 h. Timed genome-wide mRNA expression profiling upon release from drug inhibition (all 3 drugs), identification of pathway signatures, comparative genomics analysis, and evaluation of PI-103 therapeutic efficacy in an orthotopic, syngeneic allograft model system are ongoing. We have developed a genetically-defined, PTEN-deficient GEMM system for discovery of PI3K pathway-specific gene expression signatures. Comparative genomics analysis of these signatures in the human GBM TCGA dataset may ultimately permit use of expression profiling as surrogate readout for numerous DNA-level abnormalities in PI3K pathway genes and efficacy prediction for specific PI3K pathway targeted drugs.

Back to Top | Article Outline
8 Increasing YAP1 Expression In Malignant Gliomas

Brent Orr, Haibo Bai, Robert Anders, Charles Eberhart. Department of Pathology, The Johns Hopkins Medical Institutions

Members of the hippo pathway determine organ size in mammals by regulating cellular differentiation, proliferation and survival. They have also been implicated in tumor growth. The proximal mediator of the pathway is the well known tumor suppressor merlin, the protein product of the NF2 gene, while distally the pathway regulates nuclear localization of the transcriptional coactivator, yes-associated protein 1 (YAP1). The goal of our study was to evaluate expression of YAP1 in brain tumors, including those not classically associated with Neurofibromatosis Type II. Using immunohistochemistry, we found that in nodular/desmoplastic medulloblastomas prominent YAP1 expression was present in the proliferative internodular areas characterized by high hedgehog signaling, with reduced or absent staining within nodules. This is consistent with a recent report by Fernandez and colleagues (Genes Dev. 2009 Dec 1;23(23):2729-41) which found that hedgehog induces YAP1 in medulloblastomas, and validates our immunohistochemical technique. We next evaluated a panel of 164 different primary human brain tumors of various subtypes and grades for nuclear YAP1 expression, and identified immunoreactivity in 54%. All variants of medulloblastoma expressed YAP1, but as noted above the nodular variant was especially enriched for YAP1 immunoreactivity. Among glial tumors, few grade I pilocytic astrocytomas showed YAP1 immunoreactivity (29%), but nuclear YAP1 was prominent in both oligodendroglial (100%) and astrocytic infiltrating gliomas (97%). Interestingly, in these tumors the percentage of cells with nuclear YAP1 rose with increasing grade. We have confirmed YAP1 expression in several glioblastoma neurosphere lines by Western blot. Our findings support the link between the hippo and hedgehog pathways in medulloblastoma, and suggest a role for the downstream mediator YAP1 in infiltrating gliomas. We are currently overexpressing and knocking down YAP1 in glioblastoma neurosphere lines in order to determine its functional role in malignant gliomas.

Back to Top | Article Outline

PLATFORM SESSION 2: NEURODEGENERATIVE - ALZHEIMER DISEASE

9 Phosphorylated Ribosomal Protein S6 is Greatly Increased in Alzheimer Disease

Mark Smith1, Yashi Gupta2, Sandra Siedlak2, Peggy Harris2, Jeffrey Coller3, George Perry4, Xiongwei Zhu2. 1Case Western Reserve University; 2Department of Pathology, Case Western Reserve University; 3Center for RNA Molecular Biology, Case Western Reserve University; 4College of Sciences, University of Texas at San Antonio

Stress granules, intracellular dense aggregations of proteins and RNAs that accumulate when a cell is under stress, are thought to protect RNA and serve as a nexus between mRNA storage, degradation, or re-entry into translation. Since chronic stress, specifically, in the case of this study, oxidative stress, is central to the pathogenesis of Alzheimer disease (AD), we speculated that there might be alterations in stress granules. In this study, using markers for the ribosomal protein S6, a protein associated with the 40S ribosomal subunit in eukaryotes, which is used as a specific marker for stress granules, we found novel spherical structures within pyramidal neurons in AD brain. Analysis of a large series of AD and control patients showed significantly more neurons with S6 positive granules in AD compared to control (p < 0.01). Of note, in the AD cases, many S6-positive neurons did not contain neurofibrillary tangles, suggesting the accumulation of S6-positive granules reflects an alternate pathway distinct from neuronal tau phosphorylation. Previously, we showed that RNA is a major target for oxidative damage in AD, specifically accumulating 8-hydroxyguanosine, and, taken together with these findings on S6 protein, suggest that RNA modulators and RNA protection mechanisms play vital roles in neuronal viability in AD.

Back to Top | Article Outline
10 Prediction of Alzheimer's Disease by b-Amyloid Plaques and Tau Protein in Frontal Cortical Biopsy

Ville Leinonen1, Anne Koivisto1, Tomi Tillgren1, Sannakaisa Vainikka1, Sakari Savolainen1, Mikael Fraunberg1, Tuula Pirttilä1, Juha Jääskeläinen1, Hilkka Soininen1, Jaakko Rinne1, Irina Alafuzoff2. 1Kuopio University Hospital; 2Uppsala University

Introduction: Amyloid β (Aβ) aggregates together with hyperphosphorylated tau (HPt) are considered diagnostic of Alzheimer's disease (AD). According to the amyloid hypothesis, accumulation of Aβ in the brain initiates AD pathogenesis and can be seen years before dementia. We analyzed whether Aβ and/or HPt in frontal cortical biopsies, obtained during evaluation of suspected normal pressure hydrocephalus (NPH), would predict later development of AD in the biopsied patients.

Methods: Between 1991 and 2006, 468 patients with suspected NPH underwent ICP monitoring and right frontal cortical biopsy immunostained for Ab and HPt. Until the end of 2007, 249 patients had died in a median follow up time of 4 years. Their hospital and autopsy records were reviewed for possible AD or other dementia, with adequate data on 238 patients.

Results: Of the 238 cortical samples, 22 were Ab+HPt+, 85 Ab+HPt-, and 131 Ab-HPt-. Of the 238 biopsied patients, 56 developed clinical AD in a median follow-up of 3 years. With logistic regression analysis and Ab-HPt- as a reference, OD for later AD was 112.2 (95% CI 26.7-471.7, p < 0.001) with Ab+HPt+, and 9.7 (95% CI 4.0-23.3, p < 0.001) with Ab+HPt-.

Conclusion: This is apparently the largest follow-up study of patients assessed with cortical biopsy for the presence of Aβ and HPt in the brain. Our data suggest that in frontal cortical biopsy (1) Ab predicts later development of AD while (2) Ab with HPt strongly indicates the presence of AD or high risk of AD in near future.

Back to Top | Article Outline
11 TDP-43 Pathology in AD: Limbic vs. Diffuse, and the Association with HS

Steven Dubner1, E Bigio2, Manjari Mishra3, Katherine Gasho3, James Stinson4. 1Neuropathology, Northwestern Memorial Hospital; 2Northwestern Memorial Hospital; 3Alzheimer Disease Center; 4University of Michigan

There is much left to understand about the significance of TDP-43 pathology in pathological Alzheimer disease (AD). Will the decision to make a pathologic diagnosis of mixed AD/FTLD-TDP rely upon the density of inclusions, the distribution of inclusions, a combination of both, or will a likelihood chart be necessary, as with AD and DLBD. In an effort to better establish the incidence of TDP-43 pathology we examined sixty-two cases of pathologic AD (Braak V and VI) with and without hippocampal sclerosis (HS). The criteria for the pathologic diagnosis of HS were severe neuronal loss and gliosis in both sector CA-1 of the hippocampus and the subiculum. In addition to examination of H&E stained sections, all sixty-two cases were stained with either a phosphorylated (pser409/410-2, Cosmo Bio Co., Ltd., Tokyo Japan) or unphosphorylated (ProteinTech Chicago IL) TDP-43 antibody. Sections from the entorhinal cortex, hippocampus, subiculum, dentate fascia, frontal lobe, amygdala, superior, middle, and inferior temporal lobes, and striatum/basal ganglia were examined for neuronal cytoplasmic inclusions (NCIs), neuronal intranuclear inclusions (NIIs), and dystrophic neurites (DNs). Cases were given a TDP-score based on a semi-quantitative scoring system. The literature reports an incidence of TDP-43 pathology in 20-30% of pathologic AD cases. Our data support these findings, as 20/60 (33%) of the cases we stained contained TDP-43 positive inclusions. Of those 20 cases, 14 (70%) met the criteria for HS, while 6 did not. Additionally, all of the cases with HS contained TDP-43 pathology. Our results argue that FTLD-TDP-limbic is a histologic feature of HS, while FTLD-TDP-diffuse represents "true pathologic FTLD-TDP."

Back to Top | Article Outline
12 Gray and White Matter Pathology Associated With the F105L Mutation in the Presenilin 1 Gene

Matthew Hagen1, Jill Murrell1, Gregory Balko2, Masaki Takao1, Pedro Piccardo1, Ruben Vidal1, Francine Epperson1, Salvatore Spina1, Bernardino Ghetti1, Clarissa Rentz3. 1Indiana University School of Medicine, Indianapolis, IN; 2University of Cincinnati, Cincinnati, OH; 3Alzheimer's Association of Greater Cincinnati, Cincinnati, OH

Mutations in the Presenilin 1 (PSEN1) gene are known to be associated with autosomal dominant Alzheimer disease (AD) with various clinical and neuropathologic phenotypes. We present a family in which five of eight siblings had dementia. Neuropathologic studies were carried out on three of the siblings (1 male, the proband, and 2 females) who had onset of dementia at ages 44 y, 58 y, and 60 y, respectively. Neuropathologic studies were carried out using histologic and immunohistochemical methods. Panels of antibodies raised against Aβ and raised against tau were used. Genetic analysis, carried out on DNA was extracted from frozen brain tissue obtained at autopsy, revealed a single nucleotide (T to G) substitution in codon 105 of PSEN1 resulting in a leucine for phenalanine amino acid change (F105L). Analysis of the Apolipoprotein E gene revealed e3/3, e2/3 and e2/3, respectively. Neuropathologic examination showed a remarkable similarity in features among the three siblings. The brains were severely atrophic and weighed 960 g, 1070 g and 934 g. There was severe cortical atrophy, most prominent in the frontal and temporal lobes with widespread neuronal loss and gliosis, numerous neurofibrillary tangles and neuropil threads, frequent diffuse plaques, and moderate neuritic plaques. Within the white matter, scattered tau-positive glial inclusions that resemble coiled bodies were present, most frequent in subcortical U-fibers. Amyloid angiopathy composed of Aβ-40 and Aβ-42, predominantly involved the leptomeningeal vessels. Immunopositive-Aβ-42 diffuse plaques were present in the caudate and putamen. Diffuse, patchy deposition of Aβ-42 was seen in the molecular layer of the cerebellar cortex, as well as, in scattered amyloid plaques within the Purkinje and granule cell layers. Tau-positive neurofibrillary tangles were noted within multiple brainstem nuclei including the substantia nigra, locus coeruleus, and reticular formation. This study is the first detailed neuropathologic analysis of the F105L PSEN1 mutation. Supported by P30 AG010133.

Back to Top | Article Outline
13 Simultaneous Onset of Alzheimer's Disease in a Husband and Wife in Their Mid Fifties: What do We Really Know?

Jonathan Heath1, Lindsay Goicochea2, Mark Smith3, Rudy Castellani4. 1Department of Pathology, University of Maryland; 2University; 3Case Western Reserve University; 4University of Maryland, Baltimore, Maryland

Whereas the genetic factors influencing the development and expression of Alzheimer's disease are well characterized, environmental factors are currently thought to play a marginal role. Such factors as prior closed head injury, post-menopausal estrogen deficiency, aluminum exposure, smoking, diabetes, atherosclerotic cardiovascular disease, and diet, among others, confer only a modest increased risk if any, and are only tangentially considered in the major pathogenic cascades that are presently hypothesized. We present the simultaneous onset of Alzheimer's disease in a husband and wife, with both subjects experiencing cognitive dysfunction within the same month. Both subjects were in their mid-fifties at the time of presentation, both subjects showed progressively neurological decline with prominent memory loss, both subjects experienced myoclonus late in their disease course prompting referral to the National Prion Disease Pathology Surveillance Center, and both subjects expired 12 years after onset, within two months of each other. Review of the family pedigree revealed no family history of dementia or other neurologic illnesses in multiple first degree relatives. The only historical finding of note was that both subjects had moved out of their home briefly while it was being remodeled, and both became symptomatic shortly after moving back in. At autopsy, the subjects had classic advanced Alzheimer's disease, with Braak stage VI pathology that was otherwise identiical in quantity and distribution of amyloid-beta, cerebral amyloid angiopathy, and neurofibrillary degeneration. While no specific toxin or other environmental cause was discerned, these two cases raise the issue of epigenetic factors in Alzheimer's disease that may be more robust than current literature indicates.

Back to Top | Article Outline
14 Alzheimer's Disease-Type Pathology in the Non-Demented Elderly

Peter Nelson. University of Kentucky

The presence of pathology in persons who die without relevant clinical symptoms is a well-known phenomenon that has been encountered in virtually every careful autopsy series. However, the appearance of Alzheimer's disease (AD)-type pathology in older persons' brains has been a cause of confusion in the field of neurodegenerative disease research. We addressed this issue using data from the University of Kentucky AD Center (UK ADC) autopsy series and also a review of the literature. The current NIA-Reagan Institute (NIA-RI) consensus diagnostic recommendations for AD were designed to be used exclusively in the context of patients that died with documented dementia. Nonetheless, it is interesting to query how specific these diagnoses are in other contexts. Pathological diagnosis of "intermediate likelihood" for AD by NIA-RI criteria corresponds to Braak neurofibrillary stages III and IV, neither of which is by itself a substrate for profound cognitive impairment. Few non-demented patients meet the NIA-Reagan Institute criteria for pathologic diagnosis of "high likelihood" for AD, corresponding to Braak stages V and VI. Data from many research centers indicate a <3% "false-positive" rate in the NIA/Reagan criteria for "high-likelihood" AD diagnosis, with mostly Braak stage V cases. Thus it is worth scrutinizing the tendency to "lump" Braak stage V cases in with Braak stage VI cases. In addition, a number of other studies have noted that non-demented patients may have NFTs confined predominantly to the mesial temporal lobe structures. These data support the accuracy of the "high-likelihood" NIA/Reagan criteria, but leave unanswered the important question, are there non-demented persons with truly "end-stage" AD-type pathology? This issue is addressed using quantitative neuropathological data in well-documented cases from the UK ADC autopsy series.

Back to Top | Article Outline
15 Comparison of GluR2 Regulation in 3xTg-AD Mice and Incipient AD patients

Carol Miller. USC School of Medicine

In Alzheimer's Disease (AD), defining earliest molecular changes induced by Abeta oligomers (oAbeta) at the synapse, is critical for designing therapeutic strategies that prevent or delay dementia. We used the 3xTg-AD mouse to determine if temporally defined molecular modifications at the synapse parallel those reported in incipient AD patients where we found an increase in both GluR2 mRNA and protein (Williams et al, 2009 PLoS One). The GluR2 subunit, which maintains the receptors in a low conductance state, defines the properties of AMPARs, which are heteromers, consisting mainly of GluR1 and GluR2 subunits. Synaptoneurosomes were prepared from control mouse frontal cortex and assessed for enrichment of postsynaptic proteins on immunoblots. Homogenates and synaptoneurosomes isolated from frontal cortices of 3,6,9,12 month old control and 3xTg-AD mice were probed for human tau, APP and oAbeta. Immunoblots were also probed for GluR2 and phospho-GluR2 (Ser 880). Our data suggests that the mouse model validates our results from IAD and AD patients. Dimeric Abeta (dAbeta) is first visible on immunobots in patients with IAD and tends to increase with declining cognitive ability. Also an increase in synaptic GluR2 mRNA in IAD corresponds to an increase in protein expression at the synapse. In 3xTg-AD mice, dAbeta levels increase with age compared to controls particularly at 9 and 12 months. 3xTg-AD mice display increased GluR2 subunit in homogenates at 6 months compared to controls but by 9 months, and at 12 months, the disparity in GluR2 levels is synaptic. Synaptic phospho-GluR2 in 3xTg mice is similar to controls at 3 months but is 50% higher at 9 months corresponding to the elevation in synaptic GluR2 subunits. These results suggest that dAbeta induces an increase in active GluR2 expression at the synapse and thus that the 3xTg-AD mouse is a suitable model of synaptic dysfunction in AD.

Back to Top | Article Outline
16 Oxidative Stress Parameters in Newly Diagnosed Alzheimer's Disease Patients: A Population-Based Study

Katarzyna Gustaw-Rothenberg1, Alan Lerner2, Sandra Siedlak2, Xiongwei Zhu2, George Perry2,3, Mark Smith2. 1CWRU, Cleveland, USA; IMW, Lublin, Poland; 2CWRU; 3UTSA

Background: Oxidative damage to a range of biomolecules is of particular interest to AD researchers.

Aim: In this study the level of oxidative stress in a group of newly diagnosed AD patients from a population-based sample was measured.

Patients: 52 AD subjects recruited from a population-based study as well as 27 age and gender matched control patients were examined.

Methods: Plasma malondialdehyde (MDA), tripeptide glutathione (GSH) were measured and serum total antioxidant status (TAS) was calculated for samples from each study group.

Results: GSH levels were significantly reduced in AD compared to AD (0.68 vs. 1.39 mM, P < 0.001). Consistent with this, MDA levels were elevated in AD patients compared to controls (3.28 vs 1.43 mM, P < 0.001). The level of MDA did not correlate with age (CC = (-) 0.275, P > 0.05). The newly diagnosed patients were younger than the rest of the group. The time from the diagnosis, however, did correlate with age (CC = 0.56, P < 0.05). The most pronounced differences in the oxidative stress parameters were found in the newly diagnosed AD group. The level of MDA was higher in both the newly diagnosed AD patients and in those with longer lasting neurodegenerative process in comparison with controls. Both sets of data were statistically significant. GSH was significantly lower in newly diagnosed AD patients when compared to controls. TAS levels were significantly decreased in AD subjects as compared to control (0.6 vs. 1.39 mmol/L, P <0.001). The most pronounced differences in TAS levels were apparent in the AD group with the shortest history of the disease (the time from diagnosis). TAS was significantly lower in newly diagnosed AD patients when compared controls. These results strengthen the hypothesis that oxidative dyshomeostasis is an early and disease-specific phenomenon in AD development.

Back to Top | Article Outline

PLATFORM SESSION 3: INFLAMMATORY/INFECTIOUS

17 Central Nervous System Pathology in Fatal Novel Human Influenza A (H1N1) infection

A Mukherjee1, JoElle Peterson2, H Takei2, S D Sandberg3, M B Bhattacharjee4, A M Adesina4, J C Goodman5, S Powell2. 1The Methodist Hospital; 2The methodist hospital, Houston, Texas; 3Harris county medical examiner; 4The Texas Children Hospital; 5Baylor College of Medicine

Neurological complications have recently been described in children with respiratory tract infection with novel swine-origin Influenza A (H1N1) infection. However there has been no systematic study of brain pathology in fatal H1N1 Influenza A cases. The objective of our study is to document the spectrum of morphological changes found in the brains of fatal Influenza A (H1N1 infection). Retrospective study of the autopsy brains of the fatal, laboratory confirmed, Influenza A (H1N1) infection in the institutions of Texas Medical center in 2009. Nine cases were reviewed (4 male and 5 female). Average age is 17.0 years (Range 6 months-55 years.). All but two cases had some predisposing condition (COPD, asthma, bronchopulmonary dysplasia, congenital heart disease. Febrile upper respiratory tract infection was the presenting symptom in all the cases with no neurologic complications. The average period of hospitalization prior to death was 16 days (Range 7-24 days) with all cases receiving ventilator support and two cases ECMO cannulation prior to death. All cases had varying degree of cerebral edema with tonsillar herniations in 2 cases. One case had extensive unilateral subarachnoid, subdural and intraparenchymal hemorrhage, resulting in midline shift. This case also showed florid microglial activation with rare microglial nodules in the midbrain tectal plate and basal ganglia. No neurocytopathic effects were discerned. Three cases show extensive multifocal microinfarcts involving both cortical and deep grey matter as well as white matter. Multifocal brainstem perivascular microhemorrhages were noted in two cases. All cases showed mild to severe multifocal hypoxic/ischaemic change. Influenza A (H1N1) infection is a systemic infection with well documented pathologic changes in lung. Florid microglial activation in one of our cases suggests primary involvement of the brain even in cases without clinical neurologic complications. Cerebral edema, herniation, intracerebral hemorrhage, infarcts and acute hypoxic/ischemic changes reflect secondary agonal changes.

Back to Top | Article Outline
18 Classical and Alternative Activation States of Human Adult Microglia

Julia Kofler, Stephanie Bissel, Mark Stauffer, Adam Starkey, Clayton Wiley. Department of Pathology, University of Pittsburgh

Macrophages can be induced by IFN-γ and other mediators into a classical activation state that is characterized by release of proinflammatory and cytotoxic mediators. Classically activated macrophages mediate resistance against intracellular pathogens and tumor cells. Macrophages can also be stimulated by IL-4, IL-13, IL-10 or immune complexes into alternative activation states that are associated with parasite killing, tissue remodeling, wound repair and anti-inflammatory functions. The goal of our study was to determine if microglia, the resident macrophages of the brain, are capable of adopting similar activation states as peripheral macrophages. Microglial cultures isolated from postmortem adult human brain tissue and human peripheral mononuclear cell-derived macrophages were either classically stimulated by IFN-γ and LPS or alternatively stimulated by IL-4 and assessed for 48 hours. During this polarization time, both microglia and macrophages underwent distinct stimulus-dependent morphologic changes, which were more pronounced in macrophages than microglia. Culture supernatant and RNA was collected at 48 hours and analyzed for differences in chemokine secretion and gene expression. Both classically activated macrophages and microglia showed strong secretion of CXCL10 but negligible secretion of CCL17, whereas alternatively activated macrophages and microglia both demonstrated the reverse pattern with significant upregulation of CCL17 and minimal CXCL10 release. Strong polarization was also seen in gene expression levels with strong upregulation of indoleamine 2,3-dioxygenase, CXCL9 and CCR7 by classically activated cells and upregulation of mannose receptor and CCL18 by alternatively activated cells. In conclusion, these findings indicate that microglia can adopt polarized activation states in a similar fashion to peripheral monocyte-derived macrophages as assessed by chemokine secretion, gene expression profile and morphological changes. Further studies are necessary to fully characterize human microglial activation states and associated functional differences. Different modes of microglial activation may impact their role in inflammation and neurodegeneration.

Back to Top | Article Outline
19 Increased Axonal Expression of Nectin-1 in Multiple Sclerosis Plaques

Karla Castellanos1, Szatmar Horvath2, Deepak Shukla1, Howard Lipton1, Tibor Valyi-Nagy1. 1University of Illinois at Chicago; 2University of Szeged, Hungary

Nectin-1 is a cell adhesion molecule that is expressed by neurons and plays a role in axonal guidance during development and in interneuronal synapse formation. Nectin-1 expression has been shown to be upregulated in spinal motoneurons following axotomy. To better understand axonal changes in multiple sclerosis (MS) lesions, nectin-1 expression was determined by immunohistochemistry in normal adult human cerebral white matter (n = 4), and in six MS plaques (three active and three inactive). The strength of axonal nectin-1 expression was scored on a scale of 0 to 4+, where 1+ corresponded to the lowest observable expression. In normal adult cerebral white matter, axons showed weak nectin-1 expression with a score of 1.25 and a standard deviation (SD) of 0.50. Axonal nectin-1 expression was significantly stronger within both active (score = 3.33, SD = 0.289, p = 0.001) and inactive (score = 2.16, SD = 0.29, p = 0.038) MS plaques. Axons in white matter adjacent to MS plaques showed nectin-1 expression (score = 1.5, SD = 0.50) that was not statistically different from that detected in white matter from normal controls (p = 0.542). These preliminary findings suggest that axonal nectin-1 expression is increased in MS lesions and may lead to the identification of novel mechanisms by which axons react to injury in MS.

Back to Top | Article Outline
20 Avitene-Induced Necrotizing Granulomatous Inflammation Developing Post-Craniotomy: A Pediatric Case Series

liat apel-sarid1, Doug Cochrane2, Paul Steinbok2, Angela Byrne2, Christopher Dunham2. 1University of British Colimbia; 2UBC

Microfibrillar collagen hemostat (MCH), a.k.a. Avitene, is a partially water insoluble acid salt of purified bovine collagen. Avitene has been widely used to control hemorrhage, especially during pediatric neurosurgeries. Despite its effectiveness, rare case reports detailing adverse inflammatory reactions to Avitene have been documented. Based primarily upon post-surgical MRI, these reactions most commonly have elicited clinical differential diagnoses of 'tumor recurrence' or 'abscess' formation. The literature describes a very characteristic histologic appearance for Avitene that commonly evokes an eosinophil-rich mixed inflammatory reaction; as such, authors have suggested an allergic-based pathogenesis. We report the first pediatric neurosurgical case series wherein a common histomorphologic inflammatory reaction was elicited to Avitene at the site of prior craniotomy. Case 1 is of a 9 y/o male diagnosed with a parietal lobe anaplastic ependymoma. Case 2 is of a 10 y/o female diagnosed with a temporal lobe ganglioglioma. Finally, case 3 is of a 15 y/o female diagnosed with focal cortical dysplasia (FCD) type IIA affecting the occipital lobe. Each patient presented with seizures occurring within 5-6 weeks after the initial surgical resection. The post-surgical reactions incited by Avitene mimicked the radiologic appearance of either an abscess (cases 1 and 3) or tumor recurrence (case 2). Histologically, the mixed inflammatory infiltrate was typified by the appearance of Avitene-centric necrotizing granulomas that were surrounded by a palisade of macrophages, numerous plasma cells and often several eosinophils. Our findings are in keeping with previous case reports describing the clinicopathologic features of adverse reactions occurring to Avitene. Based on our observations, the possibility of an idiopathic inflammatory reaction to Avitene should be considered when there is a radiologic impression of tumor recurrence or abscess formation shortly after surgery. Moreover, early recognition of the possibility of such a reaction may avoid unnecessary patient morbidity and costly clinical investigations.

Back to Top | Article Outline
21 Synthetic Triterpenoids Induce Cytoprotective Enzymes in Astrocytic and Neuronal Cells and Attenuate Microglial Activation

Brent Harris, David Graber, William Hickey. Dartmouth Medical School

Oxidative damage and overactive immunological events are involved in the pathology of several neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Skeletal muscle atrophy and ultimately lethal paralysis in ALS are a result of the loss of the upper and lower motor neurons. The mechanism for the neuron death remains unclear and there is limited treatment to halt the clinical progression of disease. Recent evidence suggests that the nearby supporting glial cells, microglia and astrocytes, are intimately involved in creating a complex pathogenic environment. Triterpenoids belong to the group of saponin compounds and are naturally produced in some plants. They are structurally similar to cholesterol and steroids, and have biological effects in mammalian cells. A synthetic triterpenoid called 2-Cyano-3,12 dioxooleana-1,9 diene-28-imidazolide (CDDO) had been developed along with multiple derivatives. CDDO and its derivatives have enhanced action on several cellular pathways that are associated with inflammation and antioxidation/detoxification. Since signs of oxidative/nitrosative damage and localized inflammation are evidenced in motor regions of the central nervous system in ALS, these synthetic triterpenoid compounds may prove to be an effective treatment. We examined four CDDO derivatives with different functional groups at C-28 for their effects on astrocytic, neuronal, and microglial cells, in vitro. These compounds differentially induced synthesis of cytoprotective enzymes in astrocytes and neurons, as well as attenuated endotoxin-stimulated nitric oxide production in microglia. Both effects occurred at nanomolar concentrations. At higher levels, the functional group at C-28 of CDDO also altered its concentration at which direct toxicity was observed. We propose that modified synthetic triterpenoids warrant further investigation and should be tested in animal models of neurodegenerative diseases such as the mutant human SOD-1 and TDP-43 transgenic models of ALS for the ability to delay onset and prolong survival.

Back to Top | Article Outline
22 Three-Dimensional Cultures For The Identification Of Tumor Cell Subpopulations Resistant To HSV-1 Mediated Oncolytic Therapy

Tibor Valyi-Nagy1, Sandor Dosa2, Krisztian Kovacs2, Sarolta Bacsa2, Andras Voros2, Deepak Shukla2, Klara Valyi-Nagy2. 1University of Illinois, Medical Center; 2University of Illinois at Chicago

Herpes simplex virus type 1 (HSV-1) mediated oncolytic therapy is a promising novel modality of tumor therapy with potential usefulness against a wide variety of malignancies. To better understand mechanisms of tumor resistance to HSV-1 mediated oncolysis, traditional two-dimensional (2D) cultures and extracellular matrix (ECM) containing three-dimensional (3D) cultures of OCM1 and C918 uveal melanoma cells were infected with an HSV-1 strain that expresses the green fluorescent protein (GFP) marker during replication. While 2D cultures were completely destroyed within a few days of HSV-1 inoculation, viable GFP-negative tumor cells remained detectable in 3D cultures for several weeks. Tumor cells with increased resistance to HSV-1 included cells that formed vasculogenic mimicry patterns and multicellular spheroids and cells that invaded Matrigel individually. Mechanisms of tumor resistance against HSV-1 in the 3D environment included impaired virus spread in the ECM and ECM-mediated inhibition of viral replication following viral entry into tumor cells. Observations also suggested that HSV-1 established quiescent infection in some tumor cells present in multicellular spheroids and that this could revert to productive viral infection when the tumor growth pattern changed. These findings indicate that 3D tumor cell cultures can be used to identify distinct tumor cell populations with increased resistance to HSV-1 and to explore mechanisms of ECM-mediated tumor resistance to oncolytic virotherapy.

Back to Top | Article Outline
23 Induction of Neuropathology After Intracranial Inoculation of Mouse-Tropic HIV

Leroy Sharer1, Hongxia He2, Alejandra Borjabad2, Jennifer Kelschenbach2, Chao Jiang Gu2, Meilan Do1, Mary Jane Potash2, David Volsky2. 1Dept. Pathology, UMD-New Jersey Medical School; 2St. Luke's Roosevelt Hosp. and Columbia University, New York, NY

A mouse model of HIV infection uses a chimeric virus consisting of a backbone of HIV-1, with envelope sequences from murine leukemia virus. HIV-1 strains used for constructing these chimeras were a clade B virus, NL4-3, or EcoHIV, and a clade D virus, NDK, or EcoNDK. Chimeric virus was inoculated into one cerebral hemisphere of either C57Bl or 129 mice, with examination of brain tissue at 3, 6, 14 and 28 days post inoculation. Both virus strains produced microglial reaction, astrocytosis and inflammatory lesions with perivascular lymphocytes, most marked at 6 to 14 days after inoculation. More florid reaction was produced by EcoNDK than by EcoHIV, and the 129 mice developed more marked inflammation than did the C57Bl mice. Interferon receptor knock-out C57Bl mice also had more inflammation than did intact C57Bl mice. Infection of microglial cells by HIV-1 was documented by colocalization of green fluorescent protein (GFP)-labeled virus and Iba-1 as early as day 3, peaking at day 14. CD3 positive lymphocytes that appeared to be HIV-1 positive were also detected at day 6 and day 14, by immunohistochemistry for CD3 and for p24 antigen of HIV-1. Virus appeared to track inferiorly from the injection site along the external capsule. The microglial and inflammatory reaction appeared to contain infection by HIV-1, which was least apparent by day 28. Supported by DA 17618 and NS 61646.

Back to Top | Article Outline
24 IgG4-Related Pachymeningitis: Five Additional Cases of a Recently Described Entity

Katherine Lindstrom, John Cousar, M. Beatriz Lopes. University of Virginia

Background: IgG4-related disease has evolved from originally being recognized as a form of pancreatitis to encompass diseases of numerous organs including the hypophysis and one reported case of dural involvement (PMID:19561447). Here, we describe five additional cases of IgG4-related pachymeningitis.

Design: A search of the University of Virginia Neuropathology files for the past ten years identified eleven cases of unexplained, dural-based, lymphoplasmacytic lesions that were then evaluated using immunohistochemical stains for IgG4 and IgG. Ten control cases including sarcoidosis (4), tuberculosis (1), bacterial abscess (2), Langerhans cell histiocytosis (2), and foreign body reaction (1) were also examined. The number of IgG4+ plasma cells was counted in five high power fields and an average per high power field was calculated. Cases which contained greater than 10 IgG4+ cells/hpf were considered positive according to the Mayo criteria and Japan-Korea consensus criteria for diagnosing autoimmune pancreatitis (PMID: 17520222,18600383).

Results: Five of the cases of idiopathic pachymeningitis met criteria for IgG4-related sclerosing disease. All cases exhibited a lymphoplasmacytic inflammatory infiltrate with varying degrees of fibrosis. One case of an abscess, which was culture positive for S. aureus, also met the minimal criteria for IgG4-related disease.

Conclusions: Although rare, IgG4-related pachymeningitis should be considered in the differential diagnosis of dural-based inflammatory lesions. Stringent clinical and histologic criteria should be used to rule out reactive lesions.

Back to Top | Article Outline

PLATFORM SESSION 4: TUMORS - PEDIATRIC

25 MGMT Promoter Methylation Status Predicts Survival in Pediatric Glioblastoma

Adekunle Adesina1, Wenyong Zhang2, Vidya Mehta3, Girard Courteau4, Jack Su5, Ching Lau5, Renee Webb6. 1Department of Pathology, Baylor College of Medicine; 2Department of Pathology, Mount Sinai School of Medicine; 3Texas Children's Hospital; 4Texas Children's Hospital, Baylor College of Medicine; 5Texas Children's Cancer Center, Baylor College of Medicine; 6Department of Pathology, Texas Children's Hospital

Pediatric glioblastoma (pGBM) represents 15% of pediatric brain tumors with a 3-year survival rate of <20%. Effective DNA repair is an important cellular mechanism for resistance to chemotherapy and radiation. The role of this mechanism in pGBM remains poorly understood. We evaluated the expression pattern of proteins (by immunohistochemistry) involved in the repair of DNA damage induced by alkylating agents, as well as, mismatch and base excision repairs including hMLH1, hMSH2 and PARP in fifteen pGBMs. MGMT promoter methylation was analyzed using methylation specific PCR and pyrosequencing. The relationship between DNA repair pathway alteration and survival was analyzed. MGMT promoter methylation was detected in 33% of tumors. Loss of hMLH1 and hMSH2 protein expression was seen in 47% and 53% of tumors, respectively. PARP expression was seen in 100% of pGBMs. hMLH1, hMSH2 and PARP expressions did not correlate with either event free survival or overall survival (p > 0.05). MGMT promoter methylation correlated significantly with better overall survival (p = 0.029). We conclude that MGMT promoter methylation status is a predictor of better survival in treated pGBM.

Back to Top | Article Outline
26 Integrated Analysis of Copy Number Alteration and RNA Expression Profile in Pediatric Diffuse Intrinsic Pontine Glioma (DIPG)

Cynthia Hawkins, Maryam Zarghooni, Pawel Buczkowicz, Ute Bartels, Iris Fried, Uri Tabori, Eric Bouffet. The Hospital for Sick Children

DIPG is one of the most devastating of pediatric malignancies and one for which no effective therapy exists. A better understanding of the biology of DIPG itself is needed in order to develop agents targeted more specifically to these children's disease. We have already shown potential novel therapeutic targets for DIPG using high-resolution SNP-based analysis. Here we extend our initial study to expression array analysis, amalgamating the datasets to generate a more complete understanding of the genetic alterations underlying this devastating disease. Following approval by our hospital Research Ethics Board, 10 DIPGs were prospectively collected at post-mortem with consent for research purposes. A further ten DIPG biopsy samples were retrieved from our pathology archives. Seven Paired samples (tumour and normal brain) and 13 unpaired samples were hybridized to the HumanRef-8 v3.0 (DASL) or HumanWG-6 v3.0 expression beadchip from Illumina. Data were analyzed by Partek Genomics Suite (PGS) software. The common probes (18,404) between DASL and WG were selected in the two data sets and batch effects removed. The data were the analyzed using the principle component analysis (PCA) algorithm in PGS. PCA mapping showed 81.1% diversity between the tumor and normal sets. The differentially expressed genes were then identified for each sample separately using one-way ANOVA. In total, 234 genes were identified that were differentially expressed in all paired samples. Six of these genes have thus far been validated by real-time RT-PCR. The gene expression (GE) and previously generated copy number (CN) data were then integrated. In total, 147 genes showed correlation between CN and GE. Sixty genes showed deletion/underexpression while 6 genes showed gain/overexpression. The data generated through this study furthers our understanding of the biology of DIPG. This is of particular importance given the lack of efficacy of current treatment regimens and the dismal prognosis for these patients.

Back to Top | Article Outline
27 Is Claudin6 a Useful Diagnostic Marker for Atypical teratoid/rhabdoid tumor?

Felice Giangaspero1, Manila Antonelli2, Vittoria Donofrio3, Paolo Nozza4, Libero Lauriola5. 1University Sapienza, Rome & IRCCS Neuromed Pozzilli (Is); 2Dept. Experimental Medicine, University Sapienza, Rome; 3Department of Pathology Ospedale Pausilipon, Naples, Italy; 4Dept. of Pathology, Ospedale Gaslini, Genoa, Italy; 5Dept. of Pathology, Catholic University, Rome, Italy

Immunostain for INI1 is used for the diagnosis of atypical teratoid/rhabdoid (ATRT). This stain shows the loss of INI1 in ATRT tumor cell nuclei, whereas it is retained in cells of the vasculature. A microarray study of gene expression in ATRT has identified claudin6 (CLDN6) mRNA as highly and specifically express in ATRT (Birks et al. Brain Pathol 20:140-150, 2010). In this study we sought the expression of CLDN6 in a series of 15 cases of ATRT. Moreover CLDN6 expression was evaluated in 52 paediatric primary brain tumors including: 20 high grade gliomas (HGG), 2 coroid plexus papilloma (CPP), 3 pilocytic astrocytoma (PA), 5 supratentorial PNET, 1 oligodendroglioma, 1 desmoplastic infantile ganglioglioma. Nine adult diffuse gliomas (2 glioblastoma, 5 anaplastic astrocytoma, 1 oligodendroglioma, 1 oligoastrocytoma) were also evaluated. The following antibodies were used: rabbit polyclonal anti-claudin 6 (American Research Products, Belmont, MA, USA) and mouse monoclonal anti-BAF47 (INI1) (BD Transduction Laboratories, San Jose, CA, USA). Fourteen of the 15 cases of ATRT showed no INI1 nuclear staining. One case had the typical phenotype of ATRT but was INI1 positive. CLDN6 was detected in 8 out 15 cases. In one case positivity was detected in more than 50% of neoplastic cells, in 5 cases cell positivity was observed in 20-50% of cells and in two cases positivity was present in less than 10% of cells. Moreover CLDN6 immunoreactivity was detected in five out 25 pediatric HGG and in 2 out 2 CPP and 1 out of 3 PA. Among the diffuse adult gliomas CLDN6 was detected in 1 glioblastoma and 1 anaplastic oligodendroglioma. These results indicate that CLDN6 is frequently but not constantly expressed in ATRT. Moreover CLDN6 is not a specific for ATRT. However in rare cases of INI1 positive ATRT, CLDN6 may be helpful to support such diagnosis.

Back to Top | Article Outline
28 BRG1 & CRINET: Two exceptions to the Equation AT/RT = Inactivation of INI1

Martin Hasselblatt1, Michael Frühwald1, Reinhard Schneppenheim2, Florian Oyen2, Uwe Kordes2, Stefan Gesk3, Reiner Siebert3, Werner Paulus1. 1University Hospital Münster; 2University Medical Center Hamburg-Eppendorf; 3University Hospital Schleswig-Holstein Kiel

Inactivation of SMARCB1/INI1, a core member of the ATP dependent SWI/SNF chromatin remodeling complex, is characteristic for malignant rhabdoid tumors (MRT) and atypical teratoid/rhabdoid tumors (AT/RT), and loss of staining for INI1 protein is diagnostically useful. Heterozygous germline mutations have been linked to the rhabdoid tumor predisposition syndrome (RTPS). We here report two scenarios where AT/RT and deficiency of INI1 are not equivalent. Three young children (two of them sisters) were diagnosed with AT/RT and a MRT of the kidney. All tumors lacked genetic alterations of SMARCB1/INI1 and showed retained INI1 staining. In contrast, nuclear expression of SMARCA4/BRG1, another member of the SWI/SNF chromatin remodeling complex, was lost in tumor cells. Molecular genetic analyses in the two sisters revealed a germline mutation of SMARCA4/BRG1 and loss of heterozygosity by uniparental disomy in tumor cells. On the other hand, genetic alterations of SMARCB1/INI1 may occur in non-rhabdoid brain tumors: we have encountered three young children with unusual non-rhabdoid cribriform neuroepithelial tumors (CRINET) within and around the third or fourth ventricle showing well-defined EMA positive surfaces and loss of INI1 protein. Histological and immunohistochemical features did not correspond to established tumor types, including AT/RT, medulloepithelioma, choroid plexus carcinoma and ependymoma. FISH and sequencing analyses confirmed chromosomal alterations of the SMARCB1/INI1 locus in 2/3 of these non-rhabdoid tumors. Of note, the children responded well to conventional adjuvant therapy protocols: all of them are alive and in complete remission, two for more than five years postoperatively. In conclusion, BRG1 is a second member of the SWI/SNF complex underlying RTPS, and antibodies directed against BRG1 may aid in the diagnosis of INI1-positive rhabdoid tumors. On the other hand, CRINET is a non-rhabdoid, INI1-deficient ventricular tumor with relatively favorable prognosis. Our data provide evidence that the simple equation AT/RT = INI1 deficiency needs to be reconsidered.

Back to Top | Article Outline
29 Wnt/beta-Catenin and Radio-Response in Medulloblastoma Cell Lines

Giovanna Cenacchi1, Alice Ronchi2, Roberta Salaroli2, Valeria Marchese2, Elena Della Bella2, Claudio Ceccarelli2, Enza Barbieri2, Felice Giangaspero3. 1Universita' di Bologna; 2University of Bologna, Italy; 3'La Sapienza' University of Roma and Neuromed, Pozzilli, IS, Italy

Medulloblastoma (MB) is a paediatric malignant brain tumour, sensitive to ionizing radiation (IR). However radiotherapy has detrimental effects on long-term survivors and the tumour is incurable in a third of patients, due to intrinsic radioresistance. Alterations of the Wnt pathway are implicated in oncogenesis of MB and nuclear beta-catenin, indicative of activated Wnt, is associated with good outcome in MB. Therefore there are increasing evidences about Wnt involvement in radio-response: IR induces activation of Wnt signalling with nuclear traslocation of beta-catenin in MB cell lines.We studied the effects of activated Wnt on radio-response in a MB cell line, UW228-1, with p53 wild-type. Cells were stably transfected with a beta-catenin costitutively active. Several clones were selected, isolated and evaluated for nuclear beta catenin expression by immunofluorescence and PCR. Finally, cell line was irradiated and assessed for growth rate and mortality by trypan blue assay. Firstly, activation of Wnt by itself induced a slower cell growth compared to untreated UW228-1. After IR treatment, nuclear beta-catenin inhibits further cell growth, increasing mortality. These findings suggest that nuclear beta-catenin may leads to a less aggressive phenotype and increases radiosensitivity in MB, likely accounting for its favourable prognostic value. In the future, Wnt/beta-catenin signalling will be considered as a molecular therapeutic target to develop new drugs for the treatment of MB.

Back to Top | Article Outline
30 Comparative Pathology of Medulloblastoma in F-344 Rats and Humans

Dimitri Trembath1, Deepa Rao2, James Morrison3, David Malarkey2. 1University of North Carolina; 2NIEHS, NIH, DHHS, Research Triangle Park, NC; 3Charles River Labs, Pathology Associates, Durham, NC

Medulloblastomas, primitive neuroectodermal tumors of the cerebellum, often have a poor prognosis despite advances in surgery and chemotherapy. Here, we compare the morphology and immunohistochemical features of incidental medulloblastomas between F-344 rats and humans.

Twenty-four cases of medulloblastoma in F-344 rats were identified within NCI-NTP databases (1971-present). The male:female ratio was 1.4:1. Rat tumors were highly cellular and demonstrated frequent mitoses, necrosis, and apoptotic debris. Histologic features in rats not usually identified in human medulloblastomas included "glomeruloid" vascular proliferation and pseudo-palisading necrosis. Rat tumors did not reveal distinct Homer-Wright rosette formation. Immunohistochemically, the rat tumors demonstrated variable positive staining with GFAP and neuron-specific enolase. However, staining for synaptophysin and neurofilament were negative. In comparison, seventeen cases of medulloblastoma were identified from surgical pathology records at the University of North Carolina-School of Medicine over a ten-year period (1999-2009). The male:female ratio was 1.4:1, and average age at presentation was 18 years. Morphological evaluation demonstrated classic features including prominent Homer-Wright rosettes and increased mitotic/apoptotic activity. Immunohistochemically, human tumors were consistently positive for synaptophysin. Based on the WHO classification criteria, seven of the seventeen human medulloblastomas were classic-diffuse type, five were desmoplastic/nodular type, four were large cell/anaplastic type, and one demonstrated myogenic differentiation. Applying the WHO classification criteria to rat medulloblastomas, fifteen of twenty-four of rat medulloblastomas features similar to the classic-diffuse type, four were anaplastic type, three showed desmoplastic/nodular morphology, and two were extensive nodularity type. While F-344 rats have a rare spontaneous incidence (0.03% between 2003-2008) of medulloblastoma, they provide a model system that, in addition to existing mouse models, can be used to elucidate carcinogenesis and to understand tumor growth in human and rodent models. Future directions include comparative histopathology between rat, mouse and human tumors as well as genetic studies to compare molecular changes in rat and human neoplasms.

Back to Top | Article Outline
31 Pathologic and Radiologic Features of an Unusual Congenital/Infantile Variant of Astrocytoma

Mariarita Santi1, Tamara Feygin2, Hayden Head2, Brian Harding1. 1Department of Pathology Children's Hospital of Philadelphia; 2Department of Radiology Children's Hospital of Philadelphia

We report two remarkably similar, infantile astrocytomas without desmoplasia but with diffuse leptomeningeal spread including unusual cyst formation. These unrelated female infants presented at 4 months and 3 months respectively, with macrocephaly and MRI showing enlargement of almost the entire right hemisphere, an apparently smooth cortex, simplification of the gyral pattern, and expanded white matter with abnormal signal intensity containing multiple intraparenchymal cysts. Numerous extra-axial cystic lesions varying in size were seen and they enlarged with time. The histologic examination of both cases revealed white matter infiltration by a relatively hypocellular lesion composed of uniform fibrillary astrocytes in a microcystic background. Multilocular tumor cysts were prominent, but Rosenthal fibers and eosinophilic granular bodies were not present. Very rare mitoses were seen in the absence of necrosis or vascular change; proliferative index was very low. There was no convincing cortical infiltration, but the subpial zone was remarkably and diffusely expanded by a band of astrocytes set in a dense fibrillar feltwork which opened out into numerous cystic spaces. The underlying cortex revealed in one case normal lamination although with reduced sulcation, and in the other case focal areas of dyslamination without dysmorphic neurons. No desmoplastic changes or associated atypical ganglion cells were identified. In conclusion, although clearly neoplastic both lesions are not desmoplastic infantile astrocytoma/ganglioglioma or true fibrillary astrocytoma, or typical for pilocytic astrocytoma. Early onset and disturbance of cortical development hints at a congenital origin. Such extreme leptomeningeal spread with cysts is most unusual in our experience and may represent a novel variant of congenital/infantile astrocytoma. Both patients are alive at 4 and 2 years after total and subtotal resections respectively.

Back to Top | Article Outline
32 Clinical, Pathological, and Molecular Variables Define Risk-Stratification Groups in Childhood Medulloblastoma

David Ellison1, Mehmet Kocak1, James Dalton1, Hisham Megahed2, Sarra Ryan2, Meryl Lusher2, Sarah Nicholson2, Simon Bailey2, Roger Taylor3, Wei Zhao1, Steven Clifford2. 1St. Jude Children's Research Hospital; 2University of Newcastle; 3University of Swansea

Medulloblastomas are heterogeneous and include good prognosis tumors characterized by Wnt-pathway activation. Developing a therapeutic stratification that includes accurate identification of patients with low-risk disease offers the potential to reduce adjuvant therapy and minimize long-term adverse effects in a subgroup of survivors, while the identification of high-risk cases offers opportunities for treatment intensification to optimize chances of cure. Using immunohistochemistry, iFISH, direct sequencing and qPCR to identify tumors with a Wnt-pathway signature and those harboring copy number abnormalities (CNAs) of potential prognostic importance (MYC, MYCN, and chromosomes 6 and 17), we evaluated clinical, pathological and molecular outcome indicators and stratification models in a large (n = 207) cohort of medulloblastoma patients with median age 8.4 years (range: 3-16 years) and enrolled on the SIOP PNET3 trial. Metastatic disease and the large cell/anaplastic (LC/A) phenotype were the clinicopathological variables associated with poor progression-free survival. Nuclear immunoreactivity for β-catenin, CTNNB1 mutation, and monosomy 6 all identified a group of good prognosis patients. MYC amplification detected by iFISH was associated with poor outcome, but other CNAs were not. Low-risk medulloblastomas were defined as β-catenin nucleopositive tumors without LC/A phenotype or metastasis at presentation. High-risk medulloblastomas were defined as tumors with LC/A phenotype, MYC amplification, or metastatic disease. Low-risk, standard-risk, and high-risk categories of medulloblastoma had significantly (P < 0.0001) different progression-free and overall survivals. Integrating molecular assays into stratification schemes for medulloblastoma alongside clinical and pathological outcome indicators can refine the current definition of disease risk and guide the use of adjuvant therapy.

Back to Top | Article Outline

FRIDAY POSTER SESSION 1

33 Neuronal Cell Cycle Re-Entry as a Neurotoxic Mechanism of Soluble Amyloid Oligomers in Hippocampal Slice Cultures

Wataru Kudo1, Xiongwei Zhu1, Vladan Bajic2, Hyoung-gon Lee1, Mark Smith1. 1Department of Pathology, Case Western Reserve University; 2Institute of Biomedical Research, Galenika a.d. Serbia

Although oligomeric forms of amyloid-beta are thought to play an important role in Alzheimer disease (AD), the mechanisms through which amyloid-beta causes neuronal death are still unclear. Similarly, while we and others have shown that dysregulation of cell cycle re-entry is an early and obligate feature of AD and results in neurodegeneration both in vitro and in vivo, the molecular mechanisms causing neuronal cell cycle re-entry in Alzheimer disease are also unclear. In this study, we investigated the molecular basis for cell cycle re-entry associated with oligomeric amyloid-beta mediated neurotoxicity in hippocampal slice cultures. We found that oligomeric amyloid-beta oligomers cause selective and specific neuronal cell death characterized by cell cycle re-entry and the activation of calcium/calmodulin-dependent protein kinase (CaMKII) and extracellular signal-regulated protein kinase (ERK1/2) signaling pathways - the latter being responsible for the degradation of p27Kip and the consequent promotion of cell cycle progression. Notably, and consistent with an important role for these pathways, neuronal cell death mediated by oligomeric amyloid-beta was markedly and significantly reduced using specific inhibitors for ERK, cell cycle, or CaMKII. Our data demonstrate a central role for cell cycle re-entry in neuronal cell death mediated by oligomeric amyloid-beta and indicate that the CaMKII-ERK1/2 signaling pathway, by mediating the degradation of p27Kip, is a key mechanism for promulgating neuronal cell cycle progression and consequent neurodegeneration.

Back to Top | Article Outline
34 PKR Induces Glycogen Synthase Kinase 3β (GSK3β) Activation and Tau Phosphorylation

Claire PAQUET1, François MOUTON-LIGER2, Anindita BOSE2, Pierre MAZOT2, Jacques HUGON1, Francoise GRAY3. 1APHP, Hôpital Lariboisière & UMR-S 839, INSERM, Paris, France; 2Institut du Fer à Moulin, UMR-S 839 INSERM, Paris, France; 3AP-HP, Hôpital Lariboisière, Université Paris 7

Alzheimer Disease (AD) is neuropathologically characterized by the presence of senile plaques containing amyloid beta (Aβ), neurofibrillary tangles made of hyperphosphorylated tau, and neuronal loss. Previous studies have shown that the double-stranded RNA dependent protein kinase (PKR) and GSK-3β are present in degenerating neurons in post mortem AD brains, associated with granulovacular degeneration (Chang et al. J Neurochem 2002, 83:1215; Leroy et al. Acta Neuropathol 2003,103:91), and that PKR causes translocation of GSK-3β into the nucleus (Baltzis et al. J Biol Chem 2007, 282:31675). Our objective was to study the relationship between the activation of PKR and GSK-3β in AD and the action of PKR inhibitors on the activation of GSK-3β and tau phosphorylation. Immunohistochemical analysis and confocal imaging show that phosphorylated PKR and phosphorylated GSK-3β co-localize in the cytoplasm of hippocampal neurons in AD patients. In the frontal cortex they are translocated into the nuclei where they co-localize. Using immunocytochemical analysis and western blottings in neural cell cultures, we demonstrate that tunicamycin (an endoplasmic reticulum stress inducer) and Aβ 1-42 induce cytoplasmic and nuclear PKR and GSK-3β phosphorylations that are associated with apoptosis. These activations are attenuated by PKR inhibitors either C16 (oxindol imidazole) or PRI peptide (PKR inhibitor peptide) in SH-SY5Y cells. PRI also attenuates Tau phosphorylation at the AT8 epitope. Our findings suggest that PKR inhibitors could serve as new tools for reducing neuronal degeneration and tau phosphorylation in AD.

Back to Top | Article Outline
35 Neurodegenerative Changes in the Middle Aged: More Evidence of a Tau and Amyloid-Beta Disconnect

Jonathan Heath1, Sandra Richardson2, Mark Smith3, Rudy Castellani4. 1Department of Pathology, University of Maryland; 2Case Western Reserve University, Cleveland, Ohio; 3Case Western Reserve University; 4University of Maryland, Baltimore, Maryland

Studies examining neurodegenerative changes in the cognitively intact have generally focused on the elderly, with a spectrum of changes ranging from advanced Alzheimer's disease to normal brain. However, since attempts at therapeutic intervention increasingly focus on early disease, a better understanding of neurodegenerative pathology in younger age groups becomes more important. Brain tissue from twenty consecutive autopsy cases of individuals between ages 50 and 64 was examined for neurodegenerative lesions, using immunohistochemistry for phosphorylated tau (AT8), amyloid beta (4G8), ubiquitin, alpha-synuclein, and TDP-43. Retrospective review of clinical records including neurological examination indicated intact cognition in all subjects. Sampled brain regions included neocortical areas, medial temporal lobe, deep gray matter, brainstem, and cerebellum. Of the 20 subjects, all 20 had early neurofibrillary degeneration involving the locus ceruleus region, 17 out of 20 had similar changes in the nucleus basalis, 19 out of 20 had changes in the medial temporal lobe. Early neurofibrillary pathology was present in the frontal neocortex in 7 of 20 subjects. In contrast, none of the subjects had amyloid deposits in the locus ceruleus or basal nucleus, and only about half of the subjects had limited diffuse amyloid beta deposits involving the medial temporal lobe and neocortex. ApoE genotyping of the 20 subjects showed no correlation between the pathological changes and genotype. No specific pathology was noted with alpha-synuclein, TDP-43, and ubiquitin immunohistochemistry. We conclude that early neurofibrillary degeneration in the brainstem, nucleus basalis, and medial temporal lobe is typical of the middle aged brain regardless of cognitive or ApoE status. The results also confirm a spatial and temporal disconnect between amyloid-beta and phospho-tau deposits, and that phospho-tau both precedes, and occurs in the absence of, diffuse amyloid-beta deposits.

Back to Top | Article Outline
36 Age-Old Questions: the Associative Impact of Neuropathological Lesions and Clinical Parameters in Advanced Aging

Peter Nelson. University of Kentucky

Brains of individuals who died in advanced age differ from those of younger persons whether or not 'specific' pathologies are detected. However, the particular neuropathological features that are correlated with antemortem cognitive impairment are still debated. One reason for this is that there are frequently more than one pathological process occuring in the brains of older adults. A number of other obstacles and potential confounders exist in clinical-pathological correlation. Using large autopsy series with textured clinical and pathological data, we have tested the correlative impact of neuropathological lesions in relationship to antemortem final Mini-Mental Status Examination (MMSE) scores. From these studies we draw the following conclusions: 1. AD pathology as currently defined has an excellent - if sometimes misinterpreted - correlation with antemortem cognitive decline. 2. AD-related pathology outside the current consensus diagnostic guidelines, including diffuse plaques and cerebral amyloid angiopathy (CAA), do not correlate with decreased MMSE scores in our dataset when they are 'regressed' in relationship to neurofibrillary tangles and neuritic plaque quantities. 3. The impact of non-CAA cerebrovascular pathology is probably under-appreciated, especially in more advanced old age. 4. Hippocampal sclerosis has a relatively strong negative impact on cognition which underscores the importance of TDP-43 proteinopathy in aging-related cognitive decline. 5. 'Pure' neocortical Lewy body disease ('dementia with Lewy bodies, diffuse/neocortical type') is relatively rare, is far more frequently seen in males than females, and is not generally a substrate for 'end-stage' dementia as tested with the MMSE. 6. Surprisingly, the presence of some types of 'pathology' such as argyrophilic grains, and some clinical parameters such as diabetes, do not correlate with antemortem cognitive decline at all.

Back to Top | Article Outline
37 Pathological Implication of Protein Kinase C Theta in Alzheimer Disease

Hyunpil Lee, Sandra Siedlak, Mark Smith, Hyoung-gon Lee. Department of Pathology, Case Western Reserve University

Insulin mediates important processes in neurons including glucose uptake, synaptic transmission, and learning. Recent studies suggest that impaired insulin signaling may be a causative factor for neurodegeneration in Alzheimer disease (AD). However, the underlying mechanism leading to impaired insulin signaling in neurons remains to be uncovered. PKC theta, a novel calcium-independent PKC, is previously known to regulate insulin signaling in peripheral tissues, such as muscle and adipocyte and recently, it was shown that PKC theta acts as a regulator for insulin signaling in hypothalamic neurons. Given that PKC theta is expressed in many different neurons including those of the hippocampus and cerebral cortex, it may be present a key mediator for insulin signaling, and a defect in this mechanism may result in neurodegeneration in AD. Indeed, we found that the levels of active form of PKC theta (phosphorylated at Thr538 and Ser676) as well as total PKC theta were increased in the hippocampal neurons of AD compared to those of age-matched controls. Moreover, double immunofluorescence staining showed that the active form of PKC theta significantly increased in neurofibrillary tangles (NFT) bearing neurons in AD. An upstream kinase of PKC theta, phosphorylated 3-phosphoinositide-dependent kinase 1 (PDK1), was also significantly increased in these neurons. In addition, the activations of two key substrates for PKC theta, such as inhibitor κB kinase β (IKKβ) and insulin receptor substrate 1 (IRS1), which are important for insulin-mediated metabolic regulation, were increased in PKC theta positive neurons in AD, suggesting that the activation of PKC theta in neurons impedes the insulin-mediated signaling pathway. Collectively, these data strongly suggest that PKC theta may play a pivotal role in mediating insulin signaling; as its action in peripheral tissues and disturbance in its signal transduction pathway may lead to insulin resistance in neurons and subsequent neurodegeneration in AD.

Back to Top | Article Outline
38 Familial Dementia with Frontotemporal Features Associated With Met146Val Presenilin-1 Mutation

Miguel Riudavets1, Leonardo Bartoloni2, Naomi Arakaki3, Juan Troncoso4, Ana Lia Taratuto3, Peter St George-Hyslop5, Ricardo Allegri2, Gustavo Sevlever3. 1FLENI; 2Department of Neurology. Hospital Zubizarreta. Buenos Aires, Argentina; 3Department of Neuropathology. FLENI. Buenos Aires. Argentina; 4Division of Neuropathology, Johns Hopkins University. Baltimore. USA; 5Depatment of Medicine, University of Toronto. Toronto, Canada

Most of the mutations in the presenilin-1 gene (PSEN-1) are associated with familial Alzheimer's Disease (AD). However, certain examples can be associated with frontotemporal (FTD) features. We performed a clinical evaluation, molecular studies and neuropathological assessment of an individual belonging to a family with frontotemporal dementia phenotype. The PSEN-1 M146V mutation was found in a 50-year-old subject (the proband) with a positive family history of early-onset FTD. Neuropathological examination showed abundant amyloid plaques, widespread neurofibrillary pathology, presence of Pick's bodies in the hippocampus and cortex, presence of cortical globose tangles, and also ubiquitin-positive nuclear inclusions in white matter oligodendrocytes. We report a kindred with clinical features of FTD, whose proband beared the PS-1 M146V mutation, and the neuropathology displayed diffuse Alzheimer's type pathology and presence of Pick's bodies. As with other mutations within the same codon, this particular change may predispose to both AD and Pick's disease by affecting Tau and/or APP metabolism.

Back to Top | Article Outline
39 Association of Leptin Receptor with Neurofibrillary Tangles of Alzheimer Disease

Jeremy Stone1, David Bonda1, Hyoung-gon Lee1, Sandy Richardson1, George Perry2, Gemma Casadesus1, Mark Smith1. 1Department of Pathology, Case Western Reserve University; 2UTSA Neurosciences Institute and Department of Biology

Leptin signaling plays a ubiquitous role in human physiology, and as such, its transmembrane cytokine receptor, is distributed in many tissues throughout the body. While most prominently associated with body mass control and feeding behavior via its receptor activation within the hypothalamus, recent evidence implicates leptin, a peptide hormone, in the pathogenesis of the neurodegeneration in Alzheimer disease (AD). In this regard, we and others have shown that low leptin predicts both risk and course of disease, modulates tau phosphorylation, influences amyloid-β production, and affects cognition. This said, direct evidence of leptin or leptin receptor has not been demonstrated in the pathological features of AD. In this study, we aimed to elaborate on the role of leptin in AD through a comparison of leptin and leptin receptor concentrations in hippocampal tissue sections of AD and control patients. Both the activated (phosphorylated on tyrosine 985) and inactivated form of the long-isoform leptin receptor were assessed. Remarkably, a strong association between the inactivated leptin receptor was found with neurofibrillary tangles in all cases of AD studied. Taken together, these findings provide novel insights into possible signaling pathways in the pathogenesis of AD and present novel potential targets (i.e. leptin) for future therapeutic intervention.

Back to Top | Article Outline
40 Diet-Induced Obesity does not Alter Cerebral Amyloidosis in Aged Tg2576 Mice

Edward Lee, Virginia Lee, John Trojanowski, Rexford Ahima. University of Pennsylvania

Metabolic disorders including diabetes and obesity are associated with increased risk for developing Alzheimer's disease dementia. Tg2576 mice are widely used as a transgenic model of Alzheimer-type cerebral amyloidosis, but their metabolic phenotype relative to wild type is not well defined. A cohort of aged (15 to 16 mo) Tg2576 and wild type littermates were fed regular chow or a high-fat diet for three months to assess the effects of diet and genotype on energy balance and other metabolic outcomes. Tg2576 mice weighed less than wild type but percent fat content was similar on chow or high-fat diets. Although food intake was similar between the genotypes, energy expenditure and locomotor activity tended to be higher in Tg2576 mice. Serum cholesterol was lower in Tg2576 mice, but glucose, non-esterified fatty acids, triglycerides, leptin and adiponectin were similar between genotypes. Both Tg2576 and wild type mice became glucose intolerant on high-fat diet. Importantly, cerebral amyloid accumulation was not altered by high-fat diet at this age. These results demonstrate that aged Tg2576 mice are susceptible to diet-induced obesity and related alterations in glucose and other metabolites. However, this does not appear to worsen the extent of cerebral amyloidosis.

Back to Top | Article Outline
41 A Case of Variant of Alzheimer's Disease with Spastic Paraparesis Due to Missense Mutaion of Exon 8 of Presenilin 1

Namita Sinha1, David Grimes2, Ekaterina Rogaeva1, John Woulfe2. 1University of Toronto; 2University of Ottawa

A variant form of Alzheimer's disease (varAD) is characterised by spastic paraparesis (SP), dementia and "cotton wool plaques" (CWPs), and is caused by mutation in the presenilin-1 (PS1) gene on Chromosome14. The clinical diagnosis of varAD may be difficult in subjects presenting with paraparesis as the first symptom. We describe a variant form of AD with SP showing CWPs in a 66-year-old man who presented with weakness of the legs at the age 47 which progressed to spastic paraparesis. Various differential diagnoses were considered including post polio syndrome, multiple sclerosis and hereditary spastic paraparesis. Late in his course he developed dementia, dysarthria, dysphagia and supranuclear palsy and died after a year course. Subsequent histopathological examination and genetic studies revealed CWPs and a missense mutation at codon 280 in exon 8 of the presenilin-1 gene. The fact that the same PS1 mutation can be found in patients with either variant or classic AD argues in favour of the presence of a genetic modifier.

Back to Top | Article Outline
42 Alzheimer Neuropathological Changes in Brains From Subjects With Diabetes Mellitus: A Clinicopathological Study

Karra Muller, Christopher Liverman, Kathy Newell. University of Kansas Medical Center

Recent studies have suggested a link between diabetes mellitus (DM) and Alzheimer disease (AD), although this association has not been confirmed in human neuropathological studies to date. In order to investigate this possible link, Alzheimer neuropathological changes were evaluated in brains from diabetic subjects who underwent complete autopsies. Thirty brains referred for neuropathological evaluation were assessed for Alzheimer changes using immunohistochemical detection for β-amyloid and tau deposition and applying current NIA-Reagan neuropathological criteria for AD, including Braak staging. Demographics of the subjects include an age range of 45-84 years, consisting of 19 men and 11 women, representing several ethnic backgrounds. Pathological confirmation of the diabetic complications (such as coronary artery disease, neuropathy, and nephropathy), markers of the chronicity and severity of diabetes, was possible because all subjects underwent complete autopsies. Using a retrospective chart review, the Diabetes Complications Severity Index (DCSI; Young et al., Am J Manag Care 2008;14:15-23) was used to quantify diabetic complications and correlate with patient demographics, laboratory values, and Alzheimer changes. In evaluation of 30 brains, we have observed no direct relationship between DCSI and Braak stage. The Braak stages in these brains tend to be low, and most brains show low levels of β-amyloid deposits, primarily diffuse plaques. Although cognitive changes may be linked to DM in clinical studies, the neuropathological trend observed in the initial 30 brains of this study, including patients with severe diabetic complications, does not suggest a strong association with Alzheimer changes or AD. Additional neuropathological studies of diabetic brains will be required to see if this trend continues, and to explore other possible etiologies for DM related cognitive changes.

Back to Top | Article Outline
43 Pathological TDP-43 in Older Adults With and Without Severe Mental Illness

Felix Geser1, John Robinson1, Sharon Xie2, Chris Clark3, Linda Kwong1, Paul Moberg4, Erika Moore1, Vivianna Van Deerlin1, Virginia Lee1, Steven Arnold5, John Trojanowski1. 1Center for Neurodegenerative Disease Research, UPenn; 2Department of Biostatistics and Epidemiology, UPenn; 3Department of Neurology, UPenn; 4Brain-Behavior Laboratory, UPenn; 5Department of Psychiatry, UPenn

Objective: Severe mental illness (SMI) such as schizophrenia or mood disorders has not been linked to a specific pathology, but its clinical phenotype overlaps with the behavioral variant of frontotemporal lobar degeneration associated with 43 kDa (TAR) DNA binding protein (TDP-43) pathology. Therefore, we examine SMI patients for evidence of pathological TDP-43 in comparison to controls (COs).

Design: Prospective longitudinal clinical evaluation and retrospective chart review, immunohistochemical identification of pathological TDP-43 in the central nervous system, genotyping for gene alterations known to cause TDP-43 proteinopathies including the TDP-43 (TARDBP) and progranulin (GRN) genes.

Participants: 151 subjects including 91 patients with SMI (mainly schizophrenia), and 60 COs.

Results: Significant TDP-43 pathology in the amygdala/periamygdaloid region or the hippocampus/transentorhinal cortex under the age of 65 years was absent in both groups, but present in elderly subjects, i.e., 29% (25 of 86) of the psychiatric patients and 29% (10 of 34) of COs. 23% (8 of 35) of positive cases showed significant TDP-43 pathology in extended brain scans. There were no evident differences between the two groups in the frequency, degree, or morphological pattern of TDP-43 pathology. The latter included (1) subpial and subependymal, (2) focal or (3) diffuse lesions in deep brain parenchyma, and (4) perivascular pathology. A new GRN variant of unknown significance (c.620T>C, p.Met207Thr) was found in one schizophrenia patient with TDP-43 pathology. No known TARDBP mutations or other variants were found in any of the subjects studied here.

Conclusion: The similar findings of TDP-43 pathology in elderly SMI patients and COs suggest common age dependent TDP-43 changes in limbic brain areas which may signify that these regions are affected early in the course of a cerebral TDP-43 multisystem proteinopathy. Finally, our data provide an age related baseline for the development of whole brain pathological TDP-43 evolution schemata.

Back to Top | Article Outline
44 Systemic Organ Tissue Pathology in Premutation Carriers of the FMR1 Mutation

Claudia Greco1, Randi Hagerman1, Flora Tassone1, Celestine Navarro1, Marian Spath2, Renate Hukema3, Johan Kros4, Rob Willemsen3. 1M.I.N.D. Institute, University of California Davis Medical Center; 2UMC St Radboud, Nijmegen, The Netherlands; 3Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands; 4Department of Pathology, Erasmus MC, Rotterdam, The Netherlands

When first reported in 2001 (Hagerman et al), the Fragile X-associated Tremor Ataxia Syndrome (FXTAS) was described as a late-onset neurodegenerative disorder presenting with cerebellar tremor and ataxia, that occurred in premutation carriers of the FMR1 mutation. The corresponding neuropathological hallmark, reported in 2002, was the presence of intranuclear inclusions in neurons and astrocytes (Greco et al). The clinical spectrum of the disorder has since expanded beyond symptoms and signs referable to the central nervous system (Coffey et al, 2008). Similarly, additional pathological changes have been reported in FXTAS. Intranuclear inclusions have been identified in the anterior and posterior pituitary gland (Louis et al, 2006), in Leydig cells and smooth muscle cells of the testicle (Greco et al, 2007), and in the peripheral nervous system (Gokden et al, 2008). Here we report the presence of similar appearing intranuclear inclusions in systemic organ tissues taken from autopsies of six premutation carriers, and correlate these with clinical findings.

Back to Top | Article Outline
45 Fixationtime and Outcome the of Immunohistochemical Staning

Maria Pikkarainen1, Paula Martikainen1, Irina Alafuzoff2. 1University in Eastern Finland; 2Uppsala University

Introduction: The objective was to evaluate the effects of prolonged fixation time on immunohistochemical (IHC) staining of amyloid-β (Aβ), ubiquitin (Ubq), p62/sequestosome (p62), tau or a-synuclein (aS).

Material & Methods: A tissue microarray technique (TMA) and commercial antibodies (Abs) and several antigen retrieval (AR) methods were applied. Immunoreactivity (IR) was assessed in material obtain from 20 postmortem brains fixed for a short and a long time.

Results: After 14 years' fixation a good Aβ/IHC staining was obtained when formic acid (FA) AR-method was used. Also the Ubq/IR pathology was optimally labelled. The p62/IR was optimal for tissue fixed up to 10 years as well as all hyperphosphorylated-tau-Abs tested, whereas the Abs against tau isoforms RD3 and RD4 were lost in tissue fixed for a longer time. It is noteworthy that aS/IR was significantly altered with the fixation time.

Conclusions: Based on our finding one should be aware of that a prolonged fixation time might alter the IHC results.

Back to Top | Article Outline
46 Encephalopathy With Neuroserpin Inclusion Bodies Due to a Novel Mutation in the Proteinase Inhibitor 12 Gene

Matthew Hagen1, Jill Murrell1, Marie-Bernadette Delisle2, Eva Andermann3, Frederick Andermann3, Marie Christine Guiot3, Bernardino Ghetti1. 1Indiana University School of Medicine, Indianapolis, IN, USA; 2Rangueil University Hospital, Toulouse, France; 3Montreal Neurological Hospital and Institute, Montreal, QU, Canada

Neuroserpin encephalopathy is an autosomal dominant dementia associated with mutations in the Proteinase Inhibitor 12 (PI12) gene. A 26-year-old male presented with progressive myoclonus epilepsy and a declining mental status. He failed in medical school due to impaired attention, memory and concentration. Generalized seizures started to occur approximately once a month. Later, he began to have additional paroxysmal episodes, myoclonic jerks at rest, and progressive gait disturbances. Imaging revealed mild cerebral atrophy and multiple periventricular white matter lesions; consistent with multiple sclerosis. He continued to decline and died at age 34. Genetic analysis revealed a nucleotide substitution (T to C) at the second position of codon 47 located in exon 2 in one allele of the PI12 gene, resulting in a proline for leucine amino acid substitution (L47P). Neuropathologically, cerebral atrophy and multiple, well-circumscribed lesions in the white matter of the cerebrum and brain stem were seen macroscopically; consistent with multiple sclerosis. The fresh brain weighed 1147 g. Microscopic examination revealed widespread involvement of the cerebral cortex by numerous round eosinophilic inclusions in neuronal perikarya and neuropil. They were predominantly within the deep cortical layers. The inclusions varied in size, the largest being found in the neuropil. Numerous inclusions were also found in the substantia innominata, subiculum, substantia nigra, oculomotor nuclei, locus coeruleus, spinal gray matter, and dorsal root ganglia. They were less numerous within the basal ganglia, thalamus, hippocampus, and other brainstem nuclei. They were absent from the cerebellum. The inclusions were immunopositive using antibodies raised against neuroserpin. White matter lesions showed a loss of myelin stain, a perivascular lymphocytic inflammation and astrocytic reaction consistent with a diagnosis of multiple sclerosis. We report an individual affected with encephalopathy with neuroserpin inclusion bodies associated with a novel PI12 mutation and complicated by the coexistence of multiple sclerosis. Supported by P30AG010133.

Back to Top | Article Outline
47 Pathologic Findings in Rapidly Progressive Dementia in the Absence of Prion Disease

Julia Shields1, Emily Maambo2, Rudy Castellani2, Pierluigi Gambetti3. 1Department of Pathology, University of Maryland; 2University of Maryland, Baltimore, Maryland; 3Case Western Reserve University, Cleveland, Ohio

Creutzfeldt-Jakob disease (CJD) is a rare neurodegenerative condition that is unique among human disorders in being comprised of familial, sporadic, and transmitted forms. The gold standard for diagnosis is brain biopsy or brain autopsy, along with Western blot for protease resistant prion protein. Noteworthy is the fact that of all cases referred to the National Prion Disease Pathology Surveillance Center, only about 60% rule in for CJD, while the remaining 40% are negative. This raises the important question of the make up of those cases that were confused with CJD during life. We had the opportunity to examine brain tissue at autopsy from 57 subjects suffering rapidly progressive dementia, in whom CJD was clinically suspected, but also in whom CJD was rule out by molecular techniques. Of these 57 subjects, several groups were apparent: 25 subjects had neurodegenerative diseases (Alzheimer's disease, Lewy body dementia (over-represented), frontotemporal dementia, corticobasal degeneration, progressive supranuclear palsy); 11 had inflammatory diseases including vasculitis, encephalitis, acute disseminated encephalomyelitis, and multiple sclerosis; 4 had neoplastic conditions (including lymphoma, carcinoma, and malignant gliomas); and 4 subjects had no pathologic diagnosis. Other toxic and metabolic processes (e.g., mitochondrial disease, ischemic encephalopathy, toxic leukoencphelopathy) comprised the remainder. Importantly, a number of these patients tested positive for 14-3-3 protein (falsely positive) and had medical care withdrawn. In conclusion, CJD is a difficult clinical diagnosis and may be confused with a number of conditions during life, particularly Lewy body dementia and treatable inflammatory conditions. Occasionally, no structural disease is present. CSF testing for 14-3-3 protein should be utilized with the understanding that it is not a diagnostic test and therefore must be correlated with clinical data. The high frequency of clinical misdiagnoses emphasizes the importance of autopsy examination in patients with rapidly progressive dementia.

Back to Top | Article Outline
48 Limbic Encephalitis as the Initial Manifestation of Low Grade Lymphoma: A Case Report

Erin Rowe1, Beverly Greenspan2, Douglas Fellows3, Faripour Forouhar1, Qian Wu1. 1Department of Pathology, University of Connecticut Health Center; 2Department of Neurology, University of Connecticut Health Center; 3Department of Diagnostic Imaging, UCHC

Low grade lymphoma is the most common human lymphoproliferative disorder, but infrequently causes neurologic symptoms. We report an autopsy case of low grade lymphoma(small lymphocytic lymphoma) presenting clinically as limbic encephalitis. A 76-year-old female with no significant past medical history presented to the JDH in November of 2007 after being found confused and disoriented outside her home. In the ED, she suffered a witnessed tonic-clonic seizure. MRI demonstrated edema in the mesial-temporal lobe. EEG demonstrated left temporal epileptiform activity. An LP was unrevealing. The patient was treated with acyclovir, and appeared to improve. However, HSV test by PCR was negative. An antibody panel for limbic encephalitis (anti-Hu, anti-Ma, anti-Yo, anti-CV2 and VGKC) was also negative. Flow cytometry on repeat LP revealed the absence of clonal lymphocytes. The patient was discharged on Dilantin and appeared much improved. However, over the course of the next eighteen months, she became increasingly confused, developing worsening short-term memory loss, depression, and dysphagia. Ultimately she required skilled nursing placement. In February of 2009, she was found pulseless and apneic, and CMO was elected. Postmortem examinations demonstrated a diffuse lymphoproliferative disorder involving the spleen, bone marrow, GI tract, liver, appendix, uterus, breasts, and brain. The pathologic changes are mainly perivascular lymphocytic cuffing, predominantly consisting of CD20 positive B cells. Although the brain was globally involved, relative sparing of the leptomeninges was noted, and this may have limited the diagnostic value of CSF cytology studies. The diagnostic challenge was further amplified because of atypical neurologic symptoms and neuroradiologic findings.

Back to Top | Article Outline
49 CNS Mycobacterium Haemophilum Infection Manifested as a Pontine Mass in an HIV-Positive Patient. A Case Report

Li Li1, Kelly-Ann Kim1, Arnulf Koeppen2, Jiang Qian3. 1Albany Medical College; 2Albany Medical College & Stratton VA Hospital; 3Pathology, Albany Medical College/APS

Non-tuberculous mycobacteria (NTM) are increasingly identified as opportunistic pathogens in immunocompetent and immunocompromised patients. Of the more than 90 known NTMs, about one third cause diseases in humans, with M. avium intracellulare infection being the most common. M. haemophilum, first isolated in 1978, is now recognized as a rare NTM pathogen. Infection usually manifests as skin, joint, bone, or lung lesions in immunocompromised patients, or as lymphadenopathy in children. CNS Infection caused by M. haemophilum is rare. We report the case of a 43-year-old African American woman who presented with headache, photophobia, fever, vomiting, and right hemiparesis. After a period of time, HIV became reactive, CD4 cell counts declined to 25/mm3, and the viral load became greater than 51,000/microliter. Skin or lung lesions were absent. The CSF showed 620 white blood cells/mm3 (98% neutrophils), a total protein of 122 mg/100 ml, and glucose of 48 mg/100 ml. Brain imaging revealed a peripherally enhancing mass lesion in the central pons that extended into the left thalamus and middle cerebellar peduncle. Perilesional edema was extensive. Brain biopsy demonstrated an inflammatory lesion with predominant macrophages and a few lymphocytes and neutrophils. Numerous AFB-positive mycobacteria were found both inside macrophages and free in the neuropil. Culture and molecular analysis confirmed M. haemophilum. The patient received a 4-drug anti-mycobacterial regimen, improved, and was discharged. She returned due to additional fungal infections and disease progression and died 4 months after initial presentation. This case highlights the need to be aware of CNS infections by rare mycobacterial pathogens and to plan optimal doses and combinations of anti-mycobacterial drugs.

Back to Top | Article Outline
50 Primary Lateral Sclerosis Without TDP-43 Pathology: A Case Study

Jian-Qiang Lu, Jodi Carter, Wendy Johnston. University of Alberta

Primary lateral sclerosis (PLS) is rare, with limited neuropathological data. Unlike amyotrophic lateral sclerosis, the TDP-43 pathology has been detected in only one of two PLS cases and none of two PLS associated with frontotemporal lobar degeneration (except in the cortical neurons) [Dickson et al. 2007]. Therefore, it is unclear whether PLS is a TDP-43 proteinopathy. Here we report an 80-year old female patient who presented with progressive spastic dysarthria, pseudobulbar symptoms, spastic quadriparesis, hyper-reflexia and bilateral Babinski signs over nine years. Her other medical problems included type II diabetes and hypertension. Pronounced lower motor neuron findings were absent, which was confirmed by multiple electrophysiologic studies. A biceps muscle biopsy revealed angular myofibers and type II myofiber atrophy. Neuroimaging studies disclosed atrophy of the cortex and subcortical white matter preferentially in the frontal lobes. Her cognitive function was preserved initially, but declined late in life. She developed urinary symptoms in later years and died of pneumonia. Postmortem neuropathology examination showed characteristic PLS features with marked neuronal loss of the motor cortex and degeneration of the corticospinal tracts. Motor neurons in the brainstem and spinal cord were preserved. Bunina bodies were absent. There were no intracytoplasmic inclusions with TDP-43 immunohistochemistry. Dot-like immunoreactivity for ubiquitin was scattered in the brain and spinal cord, but intracytoplasmic or intranuclear inclusions were hardly found. Relatively mild degeneration of the dorsal column-medial lemniscus pathway was noted, which was partially attributed to diabetes in this patient. Mild Alzheimer changes were also seen. The paraspinal muscle exhibited the features consistent with the diagnosis of PLS. There is no evidence of secondary motor neuron disorders in this case. Along with a review of literature, this case study suggests that PLS is likely to be distinct from TDP-43 proteinopathy and pathogenetically different from ALS.

Back to Top | Article Outline
51 Phenotypic Heterogeneity and Type-1/2 PrPSc Co-Occurrence in Creutzfeldt-Jakob Disease Associated With a new Mutation of PRNP

Gianfranco Puoti1, Massimiliano Nigro1, Shu Chen1, Ignazio Cali1, Laura Cracco1, Janis Blevins1, Souhel Najjar2, Ronald L. Hamilton3, Pierluigi Gambetti1. 1Case Western Reserve University; 2New York University Medical Center; 3University of Pittsburg

We report a novel mutation of prion protein gene (PRNP) in two patients. Both subjects carried the same G54S mutation coupled with the methionine (Met) codon at position 129 of PRNP, the site of normal Met/Valine (Val) polymorphism. However, the two subjects differed in the 129 genotype of the normal allele which was Met in one subject and generated the G54S-129M,129M genotype, and Val in the other resulting in the genotype G54S-129M,129V. Surprisingly, the phenotype and the protease-resistant prion protein (PrPres) differed in the two subjects. The phenotype of the subject G54S-129M,129M strongly resembled that of the typical sporadic Creutzfeldt-Jakob disease (identified as sCJDMM1) and was associated with protease-resistant prion protein (PrPres) type 1. In contrast, the subject with the G54S-129M,129V genotype exhibited a mixed phenotype with features of both sCJDMM2 and sCJDMV2 and was associated with the co-occurrence of both PrPres types 1 and 2. Although the modifying effect on the phenotype and on PrPres type of the codon 129 when is coupled with the mutation is well known, to our knowledge this is the first observation that distinct phenotypes and PrPres types are associated with different 129 genotypes of the normal allele. (Supported by NIH AG-14395, CDC UR8/CCU515004 and Charles S. Britton Foundation; the CDC Foundation).

Back to Top | Article Outline
52 Autopsy Findings in a Case of Neurodegeneration With Brain Iron Accumulation Caused by PANK2 Mutations

Mark Hiken1, Marjorie Grafe1, Randall Woltjer1, Penelope Hogarth2, Michael Kreuer3, Susan Hayflick4. 1Dept. of Pathology (Neuropathology) Oregon Health & Science University; 2Department of Neurology Oregon Health & Science University; 3Department of Pediatrics Oregon Health & Science University; 4Dept. of Molecular & Medical Genetics Oregon Health & Science Univ.

Neurodegeneration with brain iron accumulation (NBIA) is a heterogeneous group of extrapyramidal disorders characterized by deposition of iron primarily in the basal ganglia. Age of onset, presentation, and rate of progression are variable. Autopsy findings typically include striatonigral (primarily pallidal) iron deposition and axonal spheroids; wider involvement is sometimes seen. Approximately 50% of NBIA patients have PANK2 mutations. We report autopsy findings on a patient with genetically confirmed pantothenate kinase-associated neurodegeneration (PKAN) presenting at 17 with gait abnormalities followed by worsening dysarthria, depression, and subtle general cognitive decline with increasing dystonia and spasticity until she died at 49. MRI showed the characteristic 'eye of the tiger' sign typifying PKAN. Her presentation and clinical course (late onset, slow progression) are consistent with atypical PKAN. At autopsy there was mild frontal atrophy and the medial globus pallidus, internal capsule, and subthalamic nucleus showed rusty discoloration. Microscopy showed prominent iron deposition, astrogliosis, severe neuronal loss, and APP- positive axonal spheroids in the globus pallidus. Axonal spheroids were also seen in the deep cerebral and subcortical white matter. Lesser degrees of iron deposition were found in the caudate and putamen, sparing the substantia nigra, red nucleus, and dentate nucleus. Neurofibrillary tangles, Lewy bodies, or tau or alpha-synuclein positivity were not identified. A number of NBIA autopsy cases have been published, but no others of genetically proven PKAN. Of particular interest are a number of reports of what clinically appear to be non-PKAN NBIA cases reporting different pathology than our case including more widely distributed iron deposition than seen here (or expected based on radiologic features of a large PKAN cohort) and variably alpha-synuclein positive cortical and subcortical Lewy bodies. The neuropathology of PKAN may be distinct from that of non-PKAN NBIA; interpretation of the medical literature is limited by the lack of genotype-clinical-pathological correlation.

Back to Top | Article Outline
53 Acute Disseminated Encephalomyelitis in a 16-Year Old Patient After Receiving HPV-Vaccination: A Case Report

Xianyuan Song, Francis DiMario Jr., Thomas Ciesielski, Dean Uphoff. Hartford Hospital

Acute acquired demyelination of the central nervous system (CNS) in pediatric patients may lead to a variety of clinical phenotypes depending on the site of demyelination, including optic neuritis, transverse myelitis, neuromyelitis optica, acute disseminated encephalomyelitis (ADEM), and acute multiple sclerosis. Broader definition of ADEM is applied to patients with multiple foci of white matter demyelination. About 50% of cases of ADEM follow viral exanthemata, respiratory and other infections or vaccinations. The clinical course is variable, ranging from a slow progression over weeks to a fulminant course over hours to days. HPV vaccine is only recently developed (approved in 2006), and we have not found any reports documenting the association of administration of HPV vaccine and CNS demyelinating disease (ADEM). We now report a 16-year-old female who presented with acute asymmetric, right greater than left, vision loss. MRI scan and CT showed edema with white matter changes in the right parieto-occipital, parietal junction, and an intrinsic lesion in the optic chiasm and the left optic nerve. No lesions were seen in the spinal cord. She was afebrile and alert. Right parietal biopsy showed acute inflammatory demyelination in the white matter. CSF was negative for oligoclonal bands and anti-NMO antibody, a specific marker for neuromyelitis optica. Other laboratory studies including antinuclear antibody, CMV titer, toxoplasmosis titer, double-stranded DNA, Sjogren antibody, angiotensin-converting enzyme, and antiphospholipid antibody were all normal. The patient's history included 2 injections of HPV vaccine, 2 month and 10 days before her neurological presentation. The clinical, MRI and pathological findings suggest a diagnosis of ADEM. The patient was treated with high dose steroid and IVIG. On discharge, she had some improvement in the right visual fields. ADEM after HPV vaccination is a new occurrence. Here, we report that HPV vaccine may be correlated with the occurrence of ADEM.

Back to Top | Article Outline
54 Biopsy Findings Suggestive of Spongiform Change in 2 Cases of Neuromyelitis Optica Spectrum Disorder

Kathy Newell1, Catherine Lewis1, Cynthia Gouvion1, Eugenio Taboada2, Sharon Lynch3. 1University of Kansas Medical Center, Department of Pathology; 2Children's Mercy Hospital, Kansas City, Missouri; 3University of Kansas Medical Center, Dept of Neurology

Neuromyelitis optica (NMO) is a severe demyelinating disorder recently linked to a specific serum autoantibody that reacts with the aquaporin 4 water channel. We present 2 subjects who underwent brain biopsies for evaluation of rapidly progressing neurological disorders, subsequently assessed to be NMO at autopsy. A 65 year-old woman with a 13-year history of clinical multiple sclerosis had several episodes of transverse myelitis prior to a final stroke-like presentation and died after 1 month of intensive therapy. A 13 year-old boy developed a rapidly progressive neurological disorder, including cognitive deterioration, leading to death in less than 1 year. Brain biopsies from each subject were evaluated by 2 different neuropathologists, both interpreting neuropil vacuolation as highly suggestive of spongiform change and possible prion disease. Within a few weeks of biopsy, both subjects expired and underwent complete autopsy examinations. Multiple macrophage-rich demyelinating lesions were confirmed with myelin and axon stains in the brains and spinal cords. Immunohistochemical staining of these lesions demonstrated lack of aquaporin-4 expression, aiding in the diagnosis of NMO spectrum disorder. Testing of antemortem serum from the 65 year-old woman revealed an elevated IgG NMO antibody titer. No serum from the 13 year-old boy was available for testing. Western blot analysis of frozen brain tissue from each case, performed at the National Prion Disease Pathology Surveillance Center, did not confirm prion disease. Re-evaluation of the surgical biopsies did not identify demyelinating lesions as seen at autopsy. While the vacuolation in the biopsies could be indicative of nonspecific edema, other considerations might include NMO-related pathological changes of transitional zones bordering true lesions, or incipient lesions. With the recognition of a specific biomarker now leading to differentiation of NMO from other demyelinating disease, new neuropathological insights, including characterization of more subtle or incipient lesions in the NMO brain may be realized.

Back to Top | Article Outline
55 Neuropathologic Features of the Area Postrema and the Floor of the Fourth Ventricle in Neuromyelitis Optica

Bogdan F. Popescu1, Joseph E. Parisi2, Jose A. Cabrera-Gómez3, Sean J. Pittock2, Vanda A. Lennon2, Brian G. Weinshenker2, Claudia F. Lucchinetti2. 1Mayo Clinic; 2Mayo Clinic, Rochester, MN; 3International Center of Neurological Restoration, La Habana, Cuba

Aquaporin 4 (AQP4) autoimmunity targets the medullary floor of the fourth ventricle and adjacent area postrema in neuromyelitis optica (NMO). It is not surprising, then, that intractable nausea and vomiting may be clinical manifestations of NMO patients. To further characterize the neuropathological features of NMO at the rostral medullary levels, microscopic sections including the floor of the fourth ventricle and area postrema were studied in archival autopsy tissue from 14 pathologically confirmed NMO cases. Of these, 5 cases (35.7%) demonstrated unilateral or bilateral lesions involving both the floor of the fourth ventricle and the area postrema. The lesions were characterized by tissue rarefaction and/or vacuolation, variable myelin loss with rare perivascular myelin-laden macrophages, blood vessel thickening and no obvious neuronal pathology. All 5 cases showed loss and/or marked reduction of AQP4, as well as the deposition of complement (C9neo) in astrocytes and perivascularly in a rim/rosette pattern, moderate to marked perivascular and parenchymal inflammatory cell infiltrates comprised of CD3+, CD8+, CD20+ and CD138+ lymphocytes, prominent microglial activation, and in 3 cases, eosinophils. A prominent astroglial reaction also was present with uninucleated or binucleated reactive astrocytes with prominent multiple, elongated, thin processes. In 2 patients, documented episodes of nausea and vomiting were recorded, whereas clinical information was limited in the other cases. The presence of neuropathological lesions at the level of the fourth ventricle and the area postrema likely represent the pathological substrate for the intractable but reversible nausea and vomiting reported in NMO patients.

Back to Top | Article Outline
56 Fetal "Acrania/Exencephaly": Report Of 2 Complete Autopsy Cases

Mirna Lechpammer1, Adriana Florez-Vargas2, C Buritica-Cifuentes2, Rebecca Folkerth1. 1Brigham and Women's Hospital/Children's Hospital Boston; 2Hospital Univ. Fundacion Santa Fe de Bogota, Dept. Patologia, Colombia

Failure of closure of the anterior neuropore by the 4th gestational week (GW) leads to anencephaly, in which little or no brain tissue remains over the basal cranium. Conventional wisdom holds that the prosencephalic neuroglial tissue left "exposed" to amniotic fluid degenerates by 10 GW, leaving only the area cerebrovasculosa and microscopic neuroglial remnants. Rarely, the prosencephalic brain tissue and leptomeninges do not degenerate, resulting in so-called acrania or exencephaly, terms which may be ambiguous, given that there is not isolated absence of cranial bones, nor is the brain merely "outside" of the head. Neuropathologic studies of this variant of neural tube closure defect are few, thus we report the findings in 2 fetal cases. Case 1 (from a 20-year-old G1P0) and Case 2 (from a 36-year-old G2P1), were referred for routine ultrasonographic (US) examinations at 15 GW. US showed acrania, with omphalocele also detected in Case 1, and termination of pregnancy was performed within 2 weeks. Both fetuses had karyotype 46XX. In both cases, the facies were identical to those seen in anencephaly; in addition, from the basal cranium arose an irregular, lobulated mass of disorganized brain tissue contained in a thin membrane. A V-shaped defect with smooth margins was noted at the level of the upper cervical vertebrae, the most rostral point of neural tube closure. Case 1 also had a coloboma of the iris. Microscopically, the basal cranial masses included disorganized germinal zone, intermediate zone, cortical plate, and vascular meningothelial tissue. There was no significant inflammation. We conclude that complete anterior neural tube defects may rarely present as "acrania/exencephaly", which could be considered as part of the spectrum of anencephaly. It is also analogous in some ways to intact (i.e., unruptured) caudal meningomyeloceles, occurring at the other end of the neural tube.

Back to Top | Article Outline
57 Hyperglycemia Following Pediatric Head Trauma as a Predictor of Injury Severity

Peter Cummings, Henry Nields. Office of the Chief Medical Examiner Boston MA

Elevation of blood glucose level (BGL) following head trauma is well established in the adult population. It has yet to be determined if this phenomenon occurs after pediatric head injury. A computerized data base was searched for all fatal head injuries in children 5 years of age and younger between January 2000 and January 2010. Only cases where the cause of death was listed as resulting exclusively from head injury were included. Cases with multiple traumatic injuries were excluded. An aged matched control group was comprised of deaths related to therapeutic complications with no evidence of injury (N = 5). 71 fatal head injury cases were identified. Of these, 17 had hospitalization records with admission BGL. 10 of the decedents were male and 7 female. There were 8 Whites, 5 Hispanics, 3 African Americans, and 1 Asian. There were 9 accidental deaths and 8 homicides. The average age was 24-months (accidents 33-months; homicides 14-months; p = 0206). The average BGL for the study group was 277.9 mg/dl (136-600 mg/dl) and 69.4 mg/dl (50-80 mg/dl) for the control group (p < 0.05). The average BGL in accidental deaths was 323.7 mg/dl (159-600 mg/dl) and 226.3 mg/dl (136-461 mg/dl) in homicides (p = 0.0464). Skull fractures were more common in the accidental death group (8 vs 1) as were cerebral contusions (8 vs 0). All accidental deaths with skull fractures also had basal skull fractures. There was no significant difference in the number of subdural or subarachnoid hemorrhages between the two groups. The results of this study demonstrate that increased BGL is seen following pediatric head trauma. In addition, BGL was higher in the accidental group than the homicide group. Given that there were more skull fractures, including basal skull fractures, and cerebral contusions in the accidental group, the results of this study suggest that elevations in BGL correlate with the severity of head injury.

Back to Top | Article Outline
58 Forensic Pediatric Neuropathology in a Two Year Period in Central Missouri

Douglas Miller, Carl Stacy. University of Missouri School of Medicine

The Boone & Calloway County Medical Examiner Office, an integral part of the Dept of Pathology & Anatomical Sciences at the U Missouri SoM, provides forensic pathology services to approximately 40 counties in central Missouri, including the cities of Columbia and Springfield. In 2008 we did 401 autopsies, in 2009 549. Of these 45 were 3 years old or younger. For these 24 boys and 21 girls neuropathological examinations included examination of the brain in every case, plus the spinal cord in 20 cases, and the eyes in 22 cases.

Results: Perinatal telencephalic leukoencephalopathy (Gilles) or other white matter damage was seen in 4 perinatal deaths; 5 young children died with meningitis or cerebritis; 12 had malformations or heterotopias, including several with known epilepsy; 4 had subdural hematomas, 3 documented to be victims of abusive head trauma and one with small focal SDH had undergone a traumatic delivery; and 4 had some retinal hemorrhages. Of these, a small focus of retinal hemorrhage in a 2 day old vaginally delivered child with no other signs of trauma was thought secondary to the delivery, but the 3 other cases all had more extensive and bilateral hemorrhages found together with subdural hematomas and other signs of abusive trauma. Several cases fit a clinical definition of "sudden infant death" but no autopsy showed absence/hypoplasia of the medullary arcuate nuclei or other medullary nuclei. No spinal cord abnormalities except for delayed myelination were found.

Conclusions: Careful neuropathological examination contributes to understanding cause and manner of death in this young age group, particularly in identifying likely contributing causes for sudden death (infections, malformations). Non-trivial retinal hemorrhages are strongly correlated with abusive head trauma, and are not the result of cerebral edema or congestion, or increased intracranial pressure from hypoxia, ischemia or other non-traumatic etiology.

Back to Top | Article Outline
59 Central Liponeurocytoma: A Case Report

Xianyuan Song, Srinivas Mandavilli. Hartford Hospital

Central neurocytoma is an intraventricular neoplasm comprised of neurocytes. The neurons (neurocytes) in this tumor morphologically have similarity to oligodendrocytes. The clinico-pathologic features of this tumor are well defined and include: neoplasms often arising near the foramen of Monro, intraventricular growth, and typically seen in young patients. Such tumors have also been described outside the ventricle and are referred to as "extraventricular neurocytoma". These extraventricular tumors have rarely been described to have a component of adipose tissue. This lipidized tumor has been included in the 2000 World Health Organization classification of Tumors of the Nervous System1 as "cerebellar liponeurocytoma". However, since the new terminology has been established, the first well-characterized case report of a liponeurocytoma was recently described in the anterior horn of the lateral ventricle that showed well differentiated neurocytes along with synaptophysin positive lipidized cells. 2 We also describe a case of an extracerebellar liponeurocytoma. The occurrence of this newly defined tumor outside the cerebellum calls for a redefinition of this entity from "cerebellar" to "central liponeurocytoma".

Back to Top | Article Outline
60 Two Cases of Pediatric Spinal Cord Glioblastoma Multiforme

Dana Altenburger, Gary Pearl. Orlando Health

We present two cases of pediatric spinal cord glioblastoma multiforme. The first patient is a 12 year old male who presented with a two week history of numbness that progressed to difficulty walking in December 2009. At his time of presentation, he was paraplegic for two days. An MRI was obtained at an outside facility that was read as severe myelitis. A follow-up MRI showed a discrete 13.5 cm heterogeneous spinal cord lesion extending from C4 to T7. A cerebrospinal fluid analysis was negative for malignancy and oligoclonal bands, and a high myelin basic protein was found. A biopsy was performed and a diagnosis of glioblastoma multiforme was rendered. The tumor was positive for p53, PTEN, EGFR, borderline for MGMT and negative for p21 by immunohistochemistry. The second patient presented at 12 years old with a two week history of neck pain and progressive weakness in March 2009. An MRI showed an enhancing intramedullary spinal cord lesion extending from C6 to T8 with expansion of the central cord. A cerebrospinal fluid analysis was negative for malignancy and a high myelin basic protein was found. A partial resection of the mass was performed and histology showed a glioblastoma multiforme. Immunohistochemistry was positive for p53 and PTEN. It was negative for MGMT, EGFR and p21. Glioblastoma Multiforme of the spinal cord is a rare diagnosis in children. The median age is 11 for diagnosis of high-grade spinal cord gliomas. As demonstrated by our patients, these lesions progress quickly and due to their location, are not able to be optimally excised. Due to the rarity of these lesions, there are no established guidelines for treatment. One study reported a 5-year progressive free survival of 46% with chemotherapy and radiation. Follow-up and current treatment options will be discussed at the time of the presentation.

Back to Top | Article Outline
61 Expression and Distribution of Spastin and Spliced Variants in Glioblastomas and Human Glioblastoma Cell Lines

Christos Katsetos1, Eduarda Draberova2, Simon Pei Liu3, Vladimira Sladkova2, Joanna Solowska3, Jean-Pierre de Chadarevian1, Agustin Legido1, Sverre Mork4, Peter Baas3, Pavel Draber2. 1Drexel Univ Coll of Med and St. Christopher's Hospital for Children; 2IMG, Academy of Sciences of the Czech Republic, Prague; 3Drexel University College of Medicine, Philadelphia, PA; 4Gades Institute, University of Bergen, Bergen, Norway

We have studied the expression and distribution of the microtubule severing protein spastin in three human glioblastoma cell lines (U87MG, U138MG, and T98G) and in clinical tissue samples representative of all grades of diffuse astrocytic gliomas (n = 40). Two polyclonal antibodies recognizing the high molecular weight isoform of spastin and two monoclonal antibodies (Sp 3G11/1 and Sp 6C6) recognizing a putative spliced variant of this protein (∼52 kD) were used for immunohistochemistry, immunofluorescence and immunoblotting. In the normal adult central nervous system, spastin was distributed predominantly in neurons and to a lesser extent in populations of glia. As compared to normal brain tissues, spastin immunoreactivity was significantly increased in diffuse astrocytic gliomas, especially in glioblastoma multiforme (p < 0.0005). Three overlapping patterns of cellular localization were identified in clinical tumor samples: (a) a multi-punctate cytoplasmic pattern exhibiting a proclivity for the periphery of cells, (b) a diffuse cytoplasmic pattern, seen predominantly in poorly differentiated tumor cells, and (c) a nuclear pattern. In glioblastoma cell lines, punctate and diffuse patterns, independent of Golgi staining, were observed in interphase cells and in the mitotic spindle of mitotic cells. Enrichment of spastin in the leading edges of growing tumor cells was confirmed by wound-healing cell migration assay in T98G cells. By immunoblotting, increased levels of spastin were detected in glioblastoma cells as compared to normal human astrocytes. Quantitative real-time PCR revealed a significant increase in the expression of spastin transcripts in T98G cells as compared to normal human astrocytes (p < 0.005). Our results indicate that overexpression of spastin in glioblastomas may be linked to tumor progression and anaplastic potential. The enrichment of spastin in the leading edges of glioblastoma cells suggests a possible involvement of this microtubule severing protein in microtubule dynamics during tumor cell migration and invasion.

Back to Top | Article Outline
62 Imaging Proteostasis in Pathological Conditions

Sidney Croul1, Kevin Hadley2, Michael Borrelli3, Armen Manoukian2, JoAnne McLaurin4, James Lepock2, Abhijit Guha5, Avijit Chakrabartty6. 1University of Toronto, Dept. of Lab Medicine and Pathobiology; 2Dept. of Medical Biophysics, Ontario Cancer Institute, U. of Toronto; 3Dept. of Radiology, University of Arkansas for Medical Sciences; 4Centre for Research in Neurodegenerative Diseases, U of Toronto; 5Labatts Brain Tumor Center, Hospital for Sick Children, U of Toronto; 6Dept. Biochem and Med Biophysics, Ontario Cancer Institute, U Toronto

Imbalance to proteostasis, which includes dysfunction in protein folding, trafficking, and disposal, as well as activation of the unfolded protein response, heat shock response, and endoplasmic reticulum (ER) stress is intimately linked with pathological processes ranging from neurodegeneration to malignant transformation. We present a fluorescent sensor, 1-anilino-8-naphthalenesulfonate (ANS), which, in combination with multiphoton microscopy, can be used to quantitatively detect the location of accumulated unfolded and misfolded proteins inside cells. ANS fluorescence quantifies the unfolded protein burden of cells and provides a window on proteostasis. This probe diffuses readily into cells and tissue and has very low toxicity. We demonstrate how ANS can gauge the proteostatic status in tissue sections from a mouse model of Alzheimer's disease and from human glioblastomas. We also demonstrate how ANS can be used to examine proteostasis under physical, environmental, metabolic, and ER stress in live cell cultures and animal model systems.

Back to Top | Article Outline
63 ECRG-4 Expression in Normal and Neoplastic Choroid Plexus

John Donahue1, Miles Miller1, Sonia Podvin2, Cynthia Jackson1, Conrad Johanson3, Edward Stopa1, Andrew Baird2. 1Dept. of Pathology, Rhode Island Hospital/Alpert Medical School; 2Dept. of Surgery, University of California at San Diego Medical Center; 3Dept. of Neurosurgery, Rhode Island Hospital/Alpert Medical School.

The choroid plexus is a major site of gene expression of esophageal cancer-related gene (ECRG)-4 during development, suggesting that its gene product may be involved in cerebrospinal fluid (CSF) homeostasis. Yet, ECRG-4 is also a novel candidate tumor suppressor gene whose expression is downregulated and is inversely associated with a worse prognosis in several different cancers. Reduced expression of ECRG-4 has been demonstrated in most tumors, including colorectal carcinoma and malignant glioma, to be mediated by hypermethylation of its promoter. In this study, samples of normal human choroid plexus (both fetal and adult) and choroid plexus neoplasms (WHO grade I papilloma, grade II atypical papilloma, and grade III carcinoma) were stained with antibodies that we generated to ECRG-4. Both fetal and adult human choroid plexus cells demonstrated a robust positive immunostaining at the apical surface that is consistent with our prior results in human, rat, and mouse brains. In contrast, there was an absence of immunostaining in all of the choroid plexus neoplasms examined. Taken together, these data suggest that ECRG-4 is downregulated in neoplasms of the choroid plexus just as has been observed in other central nervous system (CNS) and non-CNS cancers. Further analysis is underway to determine (1) if the mechanism of this downregulation is associated with hypermethylation of the ECRG-4 promoter, similar to other studied neoplasms, and (2) the physiologic and (3) pathophysiologic consequences of ECRG-4 over- and under- expression in the choroid plexus on CSF formation, function, and composition.

Back to Top | Article Outline
64 An Analysis of the Role of MicroRNAs in the Phenotypic Expression of Oncogenic PDGF Signaling in Malignant Glioma

Joachim Silber, Tatsuya Ozawa, Hakim Djaballah, Eric Holland, Jason Huse. Memorial Sloan-Kettering Cancer Center

Malignant gliomas continue to cause a disproportionate degree of morbidity and mortality among cancer patients while demonstrating sobering resistance to conventional therapies. Recent comprehensive genomic analyses have emphasized the importance of receptor tyrosine kinases (RTKs) and their downstream signaling cascades in the process of gliomagenesis. Among these, the platelet-derived growth factor (PDGF) pathway appears to play a crucial role in the initiation and maintenance of both low- and high-grade diffuse gliomas. An improved understanding of how PDGF signaling mediates its oncogenic effects and the mechanisms for its regulation would be of obvious benefit to the development of effective targeted therapeutics. MicroRNAs (miRNAs) are a class of small, noncoding RNAs that regulate gene expression on a pre-translational level by binding loosely complimentary sequences in target mRNAs. Each miRNA likely represses numerous mRNA targets, and this promiscuity speaks to the ability of individual miRNAs to mediate complex biological phenotypes. We have recently begun an analysis of miRNA involvement in the phenotypic expression and regulation of oncogenic PDGF signaling. We have identified a group of miRNAs whose expression levels are responsive to PDGF pathway activation in vitro and have recapitulated these findings in human glioblastomas, particularly those driven by aberrant PDGF signaling. We are now evaluating the functional properties of these miRNAs in a variety of in vitro and in vivo systems and investigating the mRNA targeting profiles of each using a combination of expression arrays and bioinformatics. We are also performing high-throughput screens to identify miRNAs that directly repress PDGF signaling and its downstream pathways. Through our studies, we hope to identify miRNA-based regulatory events impacting PDGF-mediated oncogenesis that may be amenable to therapeutic intervention.

Back to Top | Article Outline
65 Recurrent Pediatric Ganglion Cell Tumors

Bret Mobley1, Yuriko Minn2, Kristen Yeom3, Paul Fisher4, Hannes Vogel1. 1Stanford Hospital Pathology; 2Stanford Hospital Radiation Oncology; 3Lucille Packard Children's Hospital Radiology; 4Lucille Packard Children's Hospital Oncology

Ganglion cell tumors are epilepsy-associated central nervous system neoplasms that primarily affect young patients. The majority of these lesions are low grade (WHO grade I) tumors. While anaplastic (WHO grade III) ganglion cell tumors are defined as exhibiting increased mitotic activity, prominent microvascular proliferation, and necrosis, very few studies directly address the impact of these histologic features on tumor behavior. We examined clinical, radiographic, and/or histologic parameters in thirty-seven pediatric ganglion cell tumor patients with the aim of identifying features which influence patient outcome. Tumors of low grade and anaplastic histology were included in the study. When radiologic evidence of recurrent tumor was used to separate patients into "progressor" and "non-progressor" groups, non-progressors were more likely to have undergone gross total resection and were more likely to lack residual disease by initial post-operative imaging (p = 0.01 and p = 0.11 by univariate analysis, respectively). Mitotic rate and Ki-67 labeling indices differed significantly between specimens from non-progressors and primary specimens from progressors by univariate analysis (p <.01 and p <.01, respectively). At least one mitotic figure was identified in eight of the nine primary specimens from progressing tumors while a division figure was identified in only one of the seventeen non-progressing cases. We were unable to detect a relationship between vascular proliferation, necrosis, or p53 labeling and progression. To the best of our knowledge, this is the first study to describe histologic variables that differ significantly between ganglion cell tumors that do not progress and primary specimens of those tumors that do progress. Our results provide support for the use of proliferative measures including mitotic index and Ki-67 labeling in ganglion cell tumor grading.

Back to Top | Article Outline
66 Beta-Catenin and Nestin: Patterns of Expression in Human Brain Tumors

Branavan Manoranjan, John Provias. Neuropathology, Hamilton Health Sciences, McMaster University

Background: The expression profile of both nestin and beta-catenin in brain tumors has not been well established. Previous studies have suggested nestin to be a marker of poorly differentiated neuroepithelial cells and possibly endothelial cells. Beta-catenin has predominantly been associated with the activation of the Wnt/Wg pathway in medulloblastomas. The present study investigated nestin and beta-catenin by correlating their expression with tumor grade and type in endothelial and tumor cells.

Methods: Tissue samples consisted of 20 glioblastomas, low-grade astrocytomas, hemangioblastomas, and metastatic adenocarcinomas to the brain. Immunohistochemistry was performed using the streptavidin-biotin-peroxidase complex method. Percentage of positive cells was evaluated on a scale of 0 to 4.

Results: Immunohistochemical analysis with anti-nestin and anti-beta-catenin antibodies revealed cytoplasmic and membranous expression in all tumors. Increased positivity for beta-catenin in endothelial cells and nestin in tumor cells was observed as the glial tumors grade advanced (glioblastoma: 4+; low-grade astrocytoma: 2+). Perivascular niches indicative of possible neuroepithelial precursor cells were detected in some glioblastoma specimens using nestin. Hemangioblastomas generally demonstrated weak positivity for beta catenin in stromal cells (2+) and endothelial cells (1+), with increased expression for nestin in stromal and endothelial cells (3+). Within metastatic adenocarcinomas, nestin and beta-catenin were positive only in endothelial (3+) and tumour cells (4+), respectively.

Conclusions: Our results indicate nestin and beta-catenin expression in a range of brain tumors both primary and metastatic. Beta-catenin in endothelial cells and nestin in tumor cells are shown to correlate with histologic grade in glial brain tumors. Elevated nestin expression in glial tumor cells likely corresponds to the reorganization of the intermediate filament network in the cytoskeleton as some tumor cells dedifferentiate as a function of tumor progression. The role of nestin and beta-catenin in human brain tumors and specifically the progression from low to high grade gliomas warrants further investigation.

Back to Top | Article Outline
67 An Extracellular Endosulfatase that Accelerates High-Grade Gliomagenesis

Joanna Phillips1, Anna Ward1, Emmanuelle Huillard2, Steven Rosen3, David Rowitch4, Zena Werb3. 1Division of Neuropathology, Dept of Pathology, UCSF; 2Dept of Pediatrics, UCSF; 3Department of Anatomy, UCSF; 4Dept of Pediatrics, Neurosurgery and Howard Hughes Medical Inst, UCSF.

Heparan sulfate proteoglycans (HSPG) are important components of the brain extracellular matrix in the normal brain and in human glioblastoma (GBM). As HSPGs control the bioavailability of growth factors and morphogens in the extracellular environment, we hypothesized that modification of HSPG by extracellular sulfatases may be a novel mechanism by which some GBMs increase ligand-dependent cell signaling. To test this hypothesis we first adapted a robust mouse model for glioma that faithfully mimics genetic lesions etiologic in human glioblastomas (Ligon et al., 2007). Invasive malignant gliomas were generated following orthotopic transplant of neural progenitor cells isolated from transgenic Ink4a/Arf-null mice and transduced with a constitutively active variant of EGFR found in human gliomas. We found that Sulf2 transcripts were highly upregulated in the tumors by in situ hybridization and immunohistochemistry. To directly test the role of Sulf2 in tumor development, we took advantage of mutant mice with disruption of Sulf2. We demonstrate that loss of Sulf2 significantly impairs tumorigenesis. By modifying the sulfation status of HSPG, Sulf2 may regulate the activity and availability of a number of signaling molecules potentially important in glioma. In support of this idea, we demonstrate Sulf2 expression alters the activity of growth factor signaling pathways as evidenced by changes in phosphorylation of receptor tyrosine kinases and downstream signaling molecules. These data demonstrate a novel role for the extracellular sulfatase in accelerating glioma development. To demonstrate potential relevance for Sulf2 in human gliomas, we screened primary human glioblastomas for Sulf2 expression. Interestingly, Sulf2 was expressed in 29 of 59 tumors.

Back to Top | Article Outline
68 Group II Metabotropic Glutamate Receptor Allosteric Agents as Potential Tools in the Investigation and Treatment of Gliomas

Hilary Nickols1, Douglas Sheffler2, Shyama Sidique3, Dhanya Panickar3, Russell Dahl3, Li Yang3, Ananda Herath3, Robert Ardecky3, Nicholas Cosford3, P. Conn2. 1Vanderbilt University; 2Department of Pharmacology, Vanderbilt University Medical Center; 3Burnham Institute for Medical Research, La Jolla, California

Glutamate, the major excitatory neurotransmitter in the central nervous system, signals through both ionotropic and metabotropic glutamate receptors. The group II metabotropic glutamate receptors (mGluRs) include the mGluR2 and mGluR3 subtypes, which signal through Gi-proteins to inhibit adenylyl cyclase. Importantly, mGluR3 is expressed in primary human glioblastoma cultures, human glioma cell lines, and is the predominant mGluR subtype expressed in human astrocytes. Alternatively, mGluR2 and mGluR5 show variable expression in glioma cell lines. Gliomas release glutamate, which results in both excitotoxic neuronal cell death and serves as a motogen, allowing for tumor expansion within the limited confines of the cranial cavity. mGluR3 and mGluR5 have been shown to differentially modulate glutamate transporter expression in vitro and gliomas with reduced cell surface glutamate transporter expression show more rapid growth. Antagonists of mGluR2/3 have been shown to inhibit the growth of glioma cells both in vivo and in vitro, demonstrating their potential as therapeutic agents for malignant gliomas. Utilizing a high-throughput screening technique of a fluorescence-based thallium flux assay, we are screening potential group II selective agents using Hek293 cell lines stably expressing mGluR2/3 receptors and heteromeric GIRK potassium channels. Direct agonists acting at the orthosteric (glutamate) binding site have not shown receptor specificity for either mGluR2 or mGluR3 and often have therapeutic side effects that decrease their clinical utility. The development of allosteric agents has allowed for increased receptor subtype specificity. Both an mGluR3-selective allosteric antagonist and mGluR2-selective positive allosteric modulators have been identified to date. The development of mGluR2/3 selective allosteric agents may play a role in elucidating the signaling pathways and possibly in the treatment of malignant gliomas.

Back to Top | Article Outline
69 Multiplex Ligation Probe Amplification (MLPA) Detects Multiple Amplified Genes in Glioblastomas and Brain Metastases

Marie Beckner, Shashikant Patil, Long Truong, Sherry Martin, Jay LeBlanc, Kristopher Katira, Anil Nanda, Mary Nordberg. Louisiana State University Health Sciences Center - Shreveport

High grade brain tumors harbor amplified genes that may circumvent normal regulatory controls on cancer proteins. We hypothesized that these tumors can be analyzed with multiplex ligation probe amplification (MLPA) using ultrasonic aspiration specimens to identify amplified genes. Available genes for study, based on probes in commercial kits (Salsa P171, P172, and P173, MRC Holland, The Netherlands), included genes known to be amplified in human tumors. MLPA permits quantified analysis of 81 genes using 3 tubes of ligation probes and PCR primers. A thermocycler and a capillary electrophoresis instrument were used to process specimens. Commercially available normal brain DNA (81yr F) was compared with DNA of brain tumors (2 replicates) from 4 glioblastomas (44-81 yr, M:F = 3:1), 3 brain metastases (22-61 yr, M:F = 3:0), 2 meningiomas (71&83 yr M) and an ependymoma (72 yr M). Primary tumors for the metastases were a malignant germ cell tumor and lung carcinomas. All 4 glioblastomas contained at least 1 amplified gene encoding epidermal growth factor receptor (EGFR) and two contained additional amplifications of genes encoding either platelet derived growth factor receptor A (PDGFRA), CDK4, MDM2 or CYP27B1 (a vitamin D metabolic enzyme). One metastatic tumor from a lung primary contained an amplified gene encoding cyclin E1. All amplifications were at least 5-fold except for PDGFRA and CYP27B1 which were at least 3-fold greater than the corresponding gene in normal brain DNA. Correlation coefficients for genes from tumors compared to normal brain were significantly improved (p < 0.05) when amplified genes were removed except for CYP27B1 in 1 case (p < 0.07). The ependymoma and meningiomas tested did not reveal gene amplifications with these kits. Thus, excess ultrasonic aspiration specimens yield tumor DNA that can be quickly analyzed with routine techniques for amplified genes that could serve as treatment targets. Funding from LSUHSC-Shreveport Grant-In-Aid. We thank LE Brunson & D D'Souza for technical assistance.

Back to Top | Article Outline
70 Overexpression of gamma-Tubulin Transcripts in Human Glioblastoma Cell Lines

Christos Katsetos1, Eduarda Draberova2, Vladimira Sladkova2, Barbora Horejsi2, Pavel Draber2. 1Drexel UCOM and St. Christopher's Hospital for Children, Phila, PA; 2IMG, Academy of Sciences of the Czech Republic, Prague

The mammalian centrosome consists of two centrioles surrounded by amorphous pericentriolar material containing pericentrin, gamma-tubulin and associated proteins, as well as numerous other proteins including key regulators of the cell cycle. Centrosomal gamma-tubulin plays an important role in the nucleation of microtubules. In mammalian cells, two gamma-tubulin genes TUBG1 and TUBG2 exist, encoding two closely related isotypes. TUBG1 has a ubiquitous cell type distribution, whereas TUBG2 is found mainly in the brain. Previous studies have shown increased expression of gamma-tubulin in certain epithelial cancers (Oncogene 2008, 27:1554, Cancer Biol Ther. 2010, 9:1). Moreover, we have previously shown overexpression and ectopic compartmentalization of gamma-tubulin and betaIII-tubulin in glioblastoma multiforme and glioblastoma cell lines (J Neuropathol Exp Neurol 2006, 65:455; Neurochem Res 2007, 32:1387). Here we compared the expression of gamma-tubulin mRNA and protein in four human glioblastoma cell lines (U87MG, U118MG, U138MG and T98G). Quantitative real-time PCR studies have revealed significant increase in the expression of both TUBG1 and TUBG2 transcripts in all glioblastoma cell lines as compared to normal human fetal astrocytes (p < 0.01-0.005). Similarly, quantitative immunoblotting has demonstrated a coordinate increase in the expression of gamma-tubulin protein in glioblastoma cell lines as compared to normal human astrocytes. By immunofluorescence microscopy, four overlapping patterns of gamma-tubulin localization were identified in glioblastoma cells: (a) co-localization with pericentrin in the pericentriolar region, (b) pericentrin-negative puncta in the cytoplasm, (c) diffuse cytoplasmic distribution extending into the periphery of cells, and (d) a nuclear localization. The divergent localizations of gamma-tubulin and pericentrin in glioblastoma cells suggest partial dissociation and decoupling of these two centrosome-associated proteins. Our results indicate that overexpression and altered subcellular sorting of gamma-tubulin in glioblastoma cells may be significant in the context of anaplastic transformation and tumor progression and may be linked to aberrant acentrosomal microtubule nucleation in cancer cells.

Back to Top | Article Outline
71 Utility of Alpha-Internexin Immunostaining to Identify 1p/19q Co-deleted Oligodendrogliomas

Abir Mukherjee, H Takei, S Powell. The Methodist Hospital

Background: Identification of 1p/19q co-deletion in oligodendrogliomas correlates with better prognosis and response to chemotherapy. Determination of 1p/19q co-deletion is usually done by FISH, PCR or comparative genomic hybridization. A surrogate immunohistochemical marker to predict 1p/19q deletion will be cost-effective and more practical for routine histology laboratories. Recently alpha-internexin (INA) has been proposed as a reliable surrogate marker of 1p/19q codeletion.

Material and Method: INA expression was evaluated by immunohistochemistry in 14 Oligodendrogliomas (6 grade II and 8 grade III) with known 1p/19q deletion status (11 codeleted and 3 intact). Concurrent p53 immunostain were performed.

Results: INA expression was strong (>10%) positive in 5 cases (2 grade II and 3 grade III), weak (<10%) in 6 cases (3 grade II and 3 grade II) and negative in 3 cases (1 grade II and 2 grade III). Even in the cases where expression of INA was strong, the distribution was patchy.Oligodendrogliomas with 1p19q co deletion expressed INA in 91% cases (10/11, 4 strong, 6 weak). One Oligodendroglioma (grade II) with intact 1p19q showed strong INA positivity. This case also showed 20% nuclear positivity for P 53 protein. The other two Oligorogliomas with intact 1p/19q showed no INA expression. Expression of P53 protein was absent or rare in all the other cases except in one case of grade III codeleted oligodendroglioma with weak INA positivity. INA expression was 91% sensitive and 67% specific for 1p19q codeletion in our cohort.

Discussion: Our preliminary data suggests, INA expression is not a reliable surrogate marker of 1p/19q codeletion. The patchy nature of staining even in strongly positive cases is a concern. Further study in a larger cohort of cases is ongoing.

Back to Top | Article Outline
72 Gliosarcoma - An Immunohistochemical Profile Including Matrix Metalloproteinase 2 Expression

Amyn Rojiani1, Mumtaz Rojiani2, Fiona McPherson2. 1Moffitt Cancer Center, University of South Florida; 2Department of Pathology and Cell Biology, University of South Florida

Gliosarcoma is a rare malignant tumor composed of glial and mesenchymal elements. It is classified as a variant of glioblastoma (GBM) in the WHO tumor classification and comprises approximately 2% of glial tumors. The glial part of the tumor corresponds mainly to classic GBM while the mesenchymal component resembles conventional spindle-cell sarcoma typically seen outside the central nervous system. This sarcomatous portion is believed to result in greater local recurrence and infiltration. This study focuses on definition of features that may yield clues to biology of this neoplasm. Histologic sections from 20 patients with diagnosed with gliosarcoma were examined. All cases were diagnosed based either on surgical resections or cases received in consultation. Reticulin stain as well as the following immunohistochemical studies were performed: a) GFAP; b) Vimentin; c) P53; d) Ki-67 (MIB-1 protein) and e) Matrix metalloproteinases 2 (MMP-2). Reticulin elaboration was increased in the mesenchymal component and helped define the sarcomatous areas. GFAP and Vimentin expression profiles contrasted with each other in that frequently areas that were spindled or sarcomatous were Vimentin immunoreactive, while areas that were morphologically glial were GFAP positive. Ki-67 (MIB-1) labeling index (indicating proliferative activity) was markedly higher in the sarcomatous component. Additionally P53 immunoreaction, while present in both, was also greater in the sarcomatous areas of the neoplasm. MMP-2 was markedly increased in the sarcomatous areas of gliosarcoma with both intracellular and extracellular expression patterns. Matrix metalloproteinases by virtue of interactions with host stromal elements are recognized to play an important role in tumor invasion and metastasis. The findings described above suggest that the locally aggressive behavior of gliosarcomas may be associated with increased expression of MMP-2. This is also supported by the higher proliferative potential (Ki-67 labeling) detected within the sarcomatous component.

Back to Top | Article Outline
73 The Noncoding Oncofetal H19 Gene in Brain Tumors

Yakov Fellig1, Doron Amit2, Imad Matouk2, Iris Lavon3, Tali Siegal3, Abraham Hochberg2. 1Department of Pathology Hadassah-Hebrew-University-Medical-Center; 2Institute of Life Sciences Hebrew University of Jerusalem; 3Neuro-Oncology Hadassah Hebrew University Medical Center Jerusalem

H19-IGF2 locus is located within the imprinted cluster on chromosome 11p15.5. It is either highly expressed or shows aberrant allelic pattern of expression in a large array of human cancers, while not expressed in the corresponding normal tissues. Modulation of the imprinting status of H19 and IGF-2 may play an important role in the development of brain tumors. Glioblastoma derived from CD133 positive cells show high expression of H19, which might be explained by hypoxia induced up-regulation of both H19 noncoding RNA and CD133 expression. There appears to be a crucial link between the tumor suppressor gene p53 and the oncogenic H19 RNA that could determine vital processes in the tumorigenic pathway including response to hypoxic stress. H19 hypoxic induction and its tight association with mutant forms of p53 make it an ideal new target for therapy of high grade glioma. Clinical studies and human compassionate use treatments using a DNA plasmid containing H19 gene regulatory sequences that drive the expression of an intracellular toxin [diphtheria toxin A (DTA) chain]) and preclinical studies with siRNAs specifically targeting the H19 RNA have demonstrated promising results in several types of carcinomas. We have found significant expression of H19 and IGF2 in gliomas and other types of brain tumors by in-situ hybridization and RT-PCR. Both A172 and U87 human glioblastoma cell lines showed high expression of IGF2-P3 and IGF2-P4 by PCR and the A172 cell line showed high expression of H19 as well. Significant reduction of cellular quantity was observed in both cell lines after transfection with a double promoter expressing vector, carrying two separate genes expressing DTA on a single construct, from two different regulatory sequences, namely H19-DTA-P4-DTA. In light of these findings H19-IGF2 targeted vectors carrying DTA might prove efficient in the treatment of brain tumors.

Back to Top | Article Outline
74 Pilomyxoid Astrocytoma of the Foramen of Monro: A Case Report

Karen Johnson1, Laurie Ackerman2, Annette Douglas-Akinwande3, Eyas Hattab4. 1Indiana University School of Medicine, Department of Pathology; 2IUPUI-Riley Hospital; 3IUPUI-University Hospital; 4Indiana University School of Medicine-Dept of Path. and Lab. Med.

Pilomyxoid astrocytoma (PMA) is a recently described glial neoplasm that is closely related to pilocytic astrocytoma but shows a higher rate of re currence and cerebrospinal spread. The hypothalamic/chiasmatic region is by far the most common site though cases within the temporoparietal lobe, cerebellum, brain stem, and spinal cord have been reported. We describe a case of PMA arising in the formen of Monro in a 14-year-old boy who presented with headaches. MRI revealed a well-circumscribed, enhancing mass within the left foramen of Monro and anterior third ventricle causing obstructive hydrocephalus. The lesion was hypointense on T1 and hyperintense on T2 weighted images. There was no evidence of a hypothalamic or parenchymal extension. The patient underwent external ventricular drain placement, followed by gross total resection. Microscopic examination revealed a low cellular glial tumor with prominent myxoid background and focal angiocentric arrangement of tumor cells. The latter were bipolar with angulated to oval nuclei. There was moderate nuclear atypia but mitoses were difficult to find. No Rosenthal fibers or eosinophilic granular bodies were identified. Necrosis and vascular proliferation were absent. The tumor cells were immunoreactive for GFAP and vimentin but negative for EMA and synaptophysin. The Ki-67 staining index was variable, but focally elevated. The diagnosis of pilomyxoid astrocytoma, WHO grade II, was established. This case is unique in that it demonstrates the occurrence of pilomyxoid astrocytoma in a previously unrecorded site. As is the case with a newly described entity, the spectrum of site localization continues to evolve. Purely intraventricular PMAs are rare with occasional reports within the third or fourth ventricles. Because of the increased risk of local recurrence and CSF spread, the accurate identification of PMA has practical and therapeutic implications. PMA should be added to the short list of foramen of Monro lesions.

Back to Top | Article Outline
75 Oligodendroglioma Arising in a 7 Month Old Infant

Kimberly Stogner-Underwood, Gary Tye, Christine Fuller. Virginia Commonwealth University Health System

Oligodendroglioma is an infiltrating glial neoplasm most frequently seen in adults. Pediatric oligodendrogliomas are rare, and very few cases present in infancy. Case reports have demonstrated that oligodendroglioma can in rare instances present as a congenital neoplasm. In contrast with adult oligodendrogliomas, pediatric cases are frequently negative for 1p/19q deletions. We are reporting a case of WHO grade II oligodendroglioma in a 7 month old male infant. The patient initially presented with episodes of apnea and staring spells suspicious for seizures at 3 months of age. MRI showed a 2 cm contrast enhancing mass in the left temporal lobe; it was hyperintense on T2 and FLAIR, and isointense to grey matter on T1-weighted images. No cysts or calcifications were identified on imaging studies. The mass was subsequently excised, and gross total resection was achieved. The microscopic appearance was that of a classic low grade oligodendroglioma composed of cells with uniformly round nuclei with surrounding perinuclear halos, interspersed delicate, branching capillaries, and an absence of high grade features such as necrosis, frequent mitoses, endothelial proliferation, or nuclear pleomorphism. FISH studies for 1p/19q deletions were performed, and the tumor was negative for both deletions. Considering the presentation of neurological symptoms in early infancy, we suspect this case represents a congenital oligodendroglioma.

Back to Top | Article Outline
76 Astroblastoma: An Uncommon CNS Tumor Presenting as a Cyst With a Mural Nodule

Kimberly Stogner-Underwood, William Broaddus, Christine Fuller, Nitya Ghatak. Virginia Commonwealth University Health System

Astroblastoma is an exceedingly rare neuroepithelial neoplasm which usually presents in young adults. Since only a handful of cases have been reported in the literature and biological behavior is variable, no WHO grade has been established for this neoplasm. It is generally accepted however that those astroblastomas with a low grade histological appearance (lacking significant mitotic activity, vascular proliferation or palisading necrosis) tend to have a better prognosis than those with high grade features. We are reporting a case of astroblastoma with low grade histological features in a 28 year old male. The patient initially presented with a progressively more severe frontal headache accompanied by photophobia, phonophobia, nausea, and vomiting. MRI revealed an 8 cm cystic lesion in the left parietal lobe with a 2 × 0.2 cm enhancing mural nodule. Gross total resection of the cyst wall and mural nodule was achieved. Microscopically, the mural nodule was composed of bland tumor cells with stout fibrillary processes surrounding prominent, thickened vessels to form perivascular pseudorosette-like papillary structures. The tumor cells stained positive for GFAP, S-100, and vimentin, and negative for EMA and synaptophysin. The cyst wall consisted of dense gliosis with Rosenthal fibers, eosinophilic granular bodies, and hemosiderin-laden macrophages. Extensive vascular sclerosis was demonstrated by Masson's trichrome stain, a typical feature of astroblastoma. There was no evidence of necrosis or vascular proliferation, and given the low proliferation index this tumor was thus classified as a low grade astroblastoma. The patient reports post-operative symptoms of left-sided headache, balance difficulties, and significant persistent right-sided neuropathic pain, but has no MRI evidence of recurrence at 4 months post surgery.

Back to Top | Article Outline
77 Directed Pten Loss in Olig2+ Stem Cells Results in Massive Myelination and Neurodegeneration in the Absence of Neoplasia

Shakti Ramkissoon1, Cecile Maire2, Keith Ligon3. 1Division of Neuropathology, Brigham and Women's Hospital; 2Center for Molecular Oncologic Pathology, Dana-Farber Cancer Institute; 3Brigham and Women's Hospital/Dana Farber Cancer Institute

The PI3K/Pten pathway has been shown to exhibit surprisingly varied functional effects on neuronal and astrocytic proliferation, cell size, metabolism, and cancer predisposition; however, directed inactivation within the oligodendroglial lineage has been less well studied. The bHLH transcription factor Olig2 is a critical regulator of stem/progenitor cells which give rise to oligodendrocytes and is also expressed in glioma stem cells. Concurrent PI3K pathway activation is present in all OLIG2+ gliomas, with PTEN alterations representing a frequent upstream event critical to tumorigenesis. We therefore generated conditional KO mice lacking Pten activity in Olig2 cells using Olig2-tva-cre (Olig2-cre;Ptenfl/fl), in order to characterize PI3K/PTEN signaling in this stem/progenitor pool. Olig2-Cre;PTENfl/fl mice were viable and grossly normal until 10 months of age when they developed ataxia and occasional hind leg paralysis. No CNS tumors or gross developmental abnormalities were seen at any time point. Histological examination of Olig2-cre:Ptenfl/fl mice showed massively expanded white matter tracts throughout all regions of the CNS including thickened corpus callosum and pencil fibers of the striatum. Electron microscopy highlighted thickened but compact myelin sheaths associated with occasionally enlarged axons. Neurodegenerative changes included diffuse gliosis and mild sub-ventricular zone degeneration with abnormalities of progenitor proliferation and disorganization of the rostral migratory stream. Animals with paralysis harbored focally destructive spinal cord lesions of unknown etiology. Examination of Olig2-Cre;Ptenfl/fl embryonic neurospheres showed increased stem/progenitor cell proliferation and self-renewal capacity but no obvious alterations in cell fate determination. Overall these findings demonstrate that inhibition of PI3K/PTEN signaling may have yet underappreciated effects on basic oligodendrocyte biology, a finding of particular importance given the development of PI3K pathway inhibitors destined for use in glioma clinical trials. Ongoing studies will address potential metabolic and stem cell defects as well as identify secondary events capable of promoting tumorigenesis.

Back to Top | Article Outline
78 Malignant Ependymoma With Cartilage Formation in an Adult: Can Glial Cells Form Mesenchymal Tissue?

Knarik Arkun1, Patrick LaSala2, Yvonne Lui3, Karen Weidenheim4. 1Pathology, Montefiore Medical Center; 2Neurosurgery, Montefiore Medical Center; 3Neuroradiology, Montefiore Medical Center; 4Pathology, Neurology and Neurosurgery, Montefiore Medical Center

Ependymomas manifesting formation of bone and/or cartilage are rare, and eight cases found in a review of the English literature where age was documented have been pediatric cases. We report a 34 year old female presenting with acute hydrocephalus and a heterogeneous, mixed solid and cystic, enhancing mass in the fourth ventricle, the foramen of Luschka and the left cerebellopontine angle cistern, encasing the facial and vestibulocochlear nerves and elevating the trigeminal nerve. Neuropathologic study of the partially resected tumor showed a markedly cellular anaplastic ependymoma (WHO Grade III) with perivascular pseudorosettes, apoptosis, necrosis, frequent mitoses and islands of cartilage. Immunohistochemical study showed that the tumor cells expressed glial fibrillary acidic protein and epithelial membrane antigen in both the glial regions and in the cartilage islands. MIB1 was expressed in approximately 35% of tumor cell nuclei. Two months later, additional resection revealed an ependymoma primarily composed of classic Grade II ependymoma with occasional hypercellular foci similar to the initial material, and no cartilage islands. Results suggest that ependymal cells may produce cartilage while retaining their glial phenotype. Ependymomas with mesenchymal differentiation may occur in adults as well as in children.

Back to Top | Article Outline
79 Rosette-Forming Glioneuronal Tumor of the 4th Ventricle: A Pineal Region Mass With IDH1 and IDH2 Mutation Analyses

Rupal Mehta1, Orestes Solis1, Albert Lai1, Rashi Mehta1, Lama Farchoukh1, Richard Green2, Jerry Cheng2, Sathima Natarajan2, Harry Vinters1, Timothy Cloughesy1, William Yong1. 1University of California, Los Angeles; 2Kaiser Permanente, Los Angeles Medical Center

Rosette-forming glioneuronal tumor (RGNT) of the 4th ventricle is a mixed neuronal glial neoplasm recently codified by the World Health Organization (WHO 2007). To date, nearly 45 cases have been described in the literature, with most occurring in the 4th ventricle region. We report the 4th case involving the pineal region in a 16-year-old female with signs of increased intracranial pressure (ICP). A stereotactic biopsy of the mass was followed by a debulking procedure; both specimens revealed classic RGNT histology. The clinical, radiological and histopathologic features of 43 previously described cases of RGNT are reviewed here, along with our new case. Mean age of patients was 30 years ± 12.8 SD with 1.9:1 female to male ratio. The most common presenting signs included headache (62.8%), ataxia (39.5%), vomiting (16.3%) and vertigo (16.3%). Microcalcifications and satellite lesions were common radiographic observations. All reported cases showed a characteristic biphasic pattern. Rosenthal fibers and eosinophilic granular bodies were the most prevalent adjunctive pathologic findings. Ganglion cells (∼20%), mostly dysmorphic, were also noted. Ki-67 labeling index was consistently low (mean: 1.8% ±0.75 SD). Isocitrate dehydrogenase (IDH) 1 or 2 mutation, found in low grade diffuse gliomas and aggressive gangliogliomas, is not identified in our case. Though reports show an excellent prognosis following complete or subtotal resection, isolated reports of recurrence after 10 years of stable neurologic status and widespread ventricular dissemination have been published.

Back to Top | Article Outline
80 Anaplastic Astroblastoma Presenting With Massive, Sudden-Onset, Intraparenchymal Hemorrhage: A Case Report

Karen Johnson1, Joel Boaz2, Annette Douglas-Akinwande3, Jose Bonnin4, Eyas Hattab4. 1Indiana University School of Medicine, Department of Pathology; 2Indiana University-Riley Hospital; 3IUPUI-University Hospital; 4Indiana University School of Medicine-Dept of Path. and Lab. Med.

Astroblastoma is a rare primary glial tumor of children and young adults. It typically presents as a well-circumscribed, nodular, often cystic, enhancing mass involving the cerebral hemispheres. The existence of astroblastoma as a distinct clinicopathologic entity has long been debated but is recognized in the 2007 WHO classification of CNS tumors. More controversial is the grading of astroblastomas. Currently, no grade has been established and there are no definitive diagnostic criteria to distinguish low- from high-grade tumors. Astroblastomas in general are thought to have favorable outcome with low recurrence rates following gross total resection. We report a case of astroblastoma with "high-grade/anaplastic" features in a previously healthy 12-year-old girl. The patient experienced severe, sudden-onset headache, collapsed and became comatose with a right dilated pupil. Head CT scan showed a massive intraparenchymal hemorrhage in the right frontal lobe with surrounding edema and transtentorial herniation. She underwent emergency posterior frontal craniotomy for decompression and evacuation of hematoma. Intraoperatively, the presence of significant edema was suspicious for an underlying neoplasm. Pathologic examination revealed a sharply demarcated heterogeneous glial tumor with pseudopapillary architecture, prominent perivascular rosettes, densely hyalinized blood vessels, and areas of hemorrhage. The tumor cells displayed abundant eosinophilic cytoplasm with short processes arranged in a radial fashion around the blood vessels. Prominent nuclear pleomorphism and abundant mitoses were seen. Pseudopalisading and geographic necrosis, as well as vascular proliferation were also observed. The tumor cells were strongly positive for GFAP, especially around the blood vessels but negative for EMA and cytokeratin. The Ki-67 labeling index was high. Postoperatively, the patient did poorly experiencing coagulopathic disorder and suffering multiple episodes of venous thrombosis. She expired a few weeks later. This case illustrates the potentially poor outcome of high-grade astroblastomas and highlights the morphologic heterogeneity of this rare neoplasm.

Back to Top | Article Outline

PLATFORM SESSION 5: NEURODEGENERATIVE- PRIONS/OTHER

81 Expression Analysis of Metallothionein Ie and IIa in FTLD-TDP With ALS, FTLD-TDP, and Alzheimer Disease

Manjari Mishra1, Timothy Scarella2, Eileen Bigio1. 1Northwestern Cognitive Neurology and Alzheimer Disease Center; 2Northwestern Feinberg School of Medicine

Metal ion-binding metallothioneins (MTs) have been implicated in protective responses to several pathologic states in brain. It has been well documented that dysfunction of metal ion homeostasis occurs during the pathogenesis of Alzheimer Disease (AD), and may also play a role in other dementias such as frontal lobe dementias (FTLDs). Previously reported microarray studies in our lab have shown that these proteins are up-regulated in FTLDs. We further explored their status in TDP proteinopathies, FTLD-TDP with ALS (formerly FTLD-MND) and FTLD-TDP without ALS (FTLD-TDP) using quantitative RT-PCR and compared these to both non-cognitively impaired controls and AD. High metallothionein expression has already been reported in AD. RNA was isolated and purified from frozen frontal lobe tissue, and cDNAs were synthesized which subsequently were used for quantitative RT-PCR (qRT-PCR) analysis of two isoforms of metallothioneins- MT-Ie and MT-IIa. The genes for both proteins were found to be significantly up-regulated in FTLD-MND, FTLD-TDP, and AD when compared to normal controls. Compared to controls, MT-1e expression was 2.2 fold higher in FTLD-TDP with ALS, 1.8 fold higher in FTLD-TDP and 4.3 fold higher in AD cases. MT-IIa was 5.8 times higher in FTLD-MND, 2.6 times higher in FTLD-TDP and 4.7 fold higher in AD cases as compared to controls. AD cases contained the highest levels of expression, except that MT-IIa was expressed to a higher level in FTLD-MND than AD. These results suggest that MTs may play a role in the CNS defense against FTLD-TDP neurodegneration, and/or that dysfunction of metal-ion homeostasis may play a role in the pathogenesis of FTLD-TDP, with or without ALS.

Back to Top | Article Outline
82 Regulation of Progranulin Expression in Human Microglia and Astrocytes: Implications for Neuroinflammatory Diseases

Hyeon-Sook Suh, Namjong Choi, Sunhee Lee. Albert Einstein College of Medicine

Progranulin (PGRN) is a relatively newly discovered microglial protein with diverse functions described in the periphery. Haploinsufficiency resulting from mutations of PGRN cause frontotemporal lobar degeneration (FTLD). Although neurons and microglia (and astrocytes, less frequently) are known to express PGRN, little is known about the regulation and function of PGRN in the CNS. In primary cultures of human fetal microglia and astrocytes, we studied the expression of PGRN using standard ELISA and Western blot analysis. Microglia released nanogram levels of PGRN which increased further following stimulation with Th2 cytokines (IL-4 or IL-13) but not with Th1 cytokines (IFNγ ± IL-1) or toll-like receptor ligands (poly IC or LPS). LPS or poly IC often suppressed PGRN in microglia. In astrocytes, lower nanogram levels of PGRN was released and their responses to inflammatory stimuli were different from microglia, with IFNγ/IL-1 and poly IC being stimulatory. Interestingly, astrocyte expression of PGRN closely resembled that of secretory leukocyte protease inhibitor (SLPI), a known inhibitor of progranulin cleavage to inflammatory granulin. These results suggest that PGRN is a protein involved in immunoregulatory function in the brain. The immune profile suggests that PGRN expression denotes an alternative (M2) microglial activation rather than classical (M1) activation. (Supported by K01 MH094705, R01 MH55477, P30 AI051519, and Einstein CFAR Pilot Grant).

Back to Top | Article Outline
83 Hyaline Protoplasmic Astrocytopathy of Neocortex in a Case of Tangle-Predominant Dementia

John Crary, Jean Paul Vonsattel, Michael Shelanski, James Goldman. Department of Pathology and Cell Biology, Columbia University, NY, NY

Tangle-predominant dementia (TPD) is an uncommon neurodegenerative disorder characterized neuropathologically by abundant neurofibrillary tangles predominantly in limbic structures in the near absence of insoluble amyloid deposition. Here we describe a case of TPD with widespread neocortical eosinophilic astrocytic inclusions, the presence of which has recently been termed hyaline protoplasmic astrocytopathy of the neocortex [Hedley-Whyte et al., J Neuropathol Exp Neurol (2009) vol. 68 (2) pp. 136-47]. These structures have been rarely encountered in certain settings, including epilepsy and/or psychomotor retardation. Reports have further demonstrated these inclusions in a patient with arteriopathic encephalopathy with dementia and a second patient with schizophrenia harboring the prion protein P102L mutation. In the present TPD case, the inclusions were most prominent in the second to fourth layers of the neocortex, but were absent from subcortical regions. The inclusions were also identical ultrastructurally to previous reports, composed of non-membrane associated electron dense granular material. To determine the frequency of the inclusions in TPD, we reviewed 18 cases and identified three additional individuals with scattered eosinophilic astrocytic inclusions. The inclusions were positive for atypical protein kinase C ι/λ (PKCι/λ) by immunohistochemistry, a kinase widely expressed in neuronal and astrocytic inclusions [Shao et al., J Neuropathol Exp Neurol (2006) vol. 65 (4) pp. 327-35]. In conclusion, eosinophilic astrocytic inclusions are present in a subset of cases of TPD. The presence of PKCι/λ in these structures provides a link between these inclusions and other degenerative changes in the brain.

Back to Top | Article Outline
84 Pathologic Basis of Hyperintensities of Diffusion-Weighted Imaging in Creutzfeldt-Jakob Disease Using Autopsy Images of MRI

Masaki Takao1, Ban Mihara1, Shinichi Aoyagi2, Mitsutoshi Tano2, Katsura Suwabe2, Go Yasui3, Yoji Yoshida1. 1Department of Neurology Mihara Memorial Hospital; 2Department of Laboratroy Medicine, Mihara Memorial Hospital; 3Department of Radiology, Mihara Memorial Hospital

Purpose: The neuropathologic alterations of hyperintense regions using MRI-diffusion-weighted images (HI-DWI) in the cerebral cortex of patients diagnosed with Creutzfeldt-Jakob disease (CJD) are not well analyzed. Previous studies suggested that severe spongiform change is associated with HI-DWI. However, those studies always have limitations that are related to the time lapse between MRI scanning and autopsy. The present study seeks to clarify the neuropathologic basis of HI-DWI in CJD using autopsy images of MRI (AIs-MRI).

Methods: Six individuals with CJD (MM1) were analyzed in this study. AIs of 3T-MRI were administered just before each autopsy as previously reported (Takao et al. JNEN 2007;66:430). Fixed brains were dissected at the exact same levels of AIs-MRI. Sections were stained using conventional and immunohistochemical methods. Sections, at the same level of HI-DWI-AIs, were evaluated using semiquantitative analysis (0 = none, 1 = mild, 2 = moderate, 3 = severe) of neuronal loss, gliosis, spongiform change and PrPsc (3F4) deposits. The same assessment was carried out in the normal intense regions of DWI-AIs.

Results: Four of the six cases showed local HI-DWI-AIs in the cerebral cortex (motor cortex in two cases and cingulate gyrus in two cases). Since no HI-DWI-AIs were seen in the other cortical regions, we compared the rates of semiquantitative analysis in HI-DWI-AIs with that of the temporal cortex (TCx). There were no statistical differences of gliosis and PrPsc deposits between the cortex with HI-DWI-AIs and TCx. The mean score of neuronal loss in the HI-DWI-AIs was smaller than that of TCx (2.33 vs. 2.91, p < 0.05). The HI-DWI-AIs also showed a much lower rate of spongiform change than in TCx (1.33 vs. 2.58, p < 0.05).

Conclusions: This is the first analysis of direct correlation of neuropathology and HI-DWI of CJD using AIs. The early pathologic changes, mild spongiform changes and neuronal loss, are associated with HI-DWI of CJD.

Back to Top | Article Outline
85 TDP-43 Proteinopathy in Cognitively Normal (CDR 0) Individuals

Lisa Taylor-Reinwald, Elizabeth Grant, John Morris, Nigel Cairns. Washington University School of Medicine

Background: TAR DNA-binding protein of 43 kDa (TDP-43) is a major component ofthe inclusions in frontotemporal lobar degeneration (FTLD) with and without motor neuron disease (MND) and amyotrophic lateral sclerosis (ALS) and a minor component of other disorders. Here we report the presence of TDP-43 positive inclusions in cognitively normal (CDR 0) individuals.

Methods: Brains from 36 prospectively assessed participants who were cognitively normal at the time of expiration with a Clinical Dementia Rating (CDR) of zero, were obtained at autopsy. The CDR of each case was determined by clinicians in the Memory and Aging Project of the Washington University Alzheimer's Disease Research Center. Brains were fixed in 10% neutral buffered formalin, coronally sliced, and regions of interest were sampled and embedded in paraffin. Cases were assessed for Alzheimer's pathology, Lewy body pathology, vascular lesions, and other neurodegenerative diseases using a standard protocol applied to 15 brain areas. Histology and immunohistochemistry was performed on all 15 regions. Histology included: hematoxylin and eosin and a modified Bielschowsky silver impregnation. Immunohistochemistry was performed using anti-beta-amyloid (10D5), anti-tau (PHF-1), anti-alpha-synuclein, and anti-TDP-43 antibodies. AD changes and Lewy body pathology were assessed using established criteria.

Results: TDP-43-positive inclusions were identified in 4 of 36 (11%) cognitively normal individuals. Lewy bodies were identified in 4 of 36 (11%) individuals. One case (2.7%) had combined TDP-43 and alpha-synuclein-immunoreactive inclusions.

Conclusions: TDP-43 positive inclusions have previously been identified in a spectrum of diseases including FTLD, FTLD-MND, MND, and AD. Here we report that TDP-43 proteinopathy is also minor component of the molecular pathology of the aged cognitively normal individual. TDP-43 proteinopathy in these cases may reflect a pre-clinical stage of disease and its contribution to AD and Lewy body pathology remains to be determined.

Back to Top | Article Outline
86 Protease-Sensitive Prionopathy in a Cognitively Normal 93 Year Old

Nupur Ghoshal1, G Puoti2, Pierluigi Gambetti2, John Morris1, Nigel Cairns1. 1Washington University School of Medicine; 2National Prion disease Pathology Surveillance Center, Cleveland, Ohio

Background: Protease-sensitive prionopathy (PSPr) is a recently described novel prion disease biochemically characterized by abnormal prion protein (PrP) sensitiveto proteases resulting in a distinct profile by immunoblotting. Clinically, cases reported to date have presented with behavioral and psychiatric symptoms with an average age at onset of 62 years and with a mean disease duration of 20 months.

Methods: The individual was clinically examined between 1996-2002, including semi-structured interviews, Clinical Dementia Rating (CDR) and Mini-Mental State Exam (MMSE) assessments, and retrospective postmortem dementia interview of surviving family. After death, the brain was examined and processed using standard neuropathologic methods and tau, beta amyloid, and PrP immunohistochemistry. DNA was extracted from frozen brain tissue for sequence analysis. Frozen brain tissue was also used for Western blot analyses.

Results: This individual was cognitively intact during her initial assessment (CDR 0; MMSE 30) at age 87 and remained cognitively unchanged until her death at age 93 (CDR 0). Furthermore, no neurologic abnormalities associated with prion disease were observed. At autopsy, the fresh brain weight was 1,180 g. Macroscopically, there was mild frontal atrophy; however, the basal ganglia and cerebellum were unremarkable. Neuronal loss, gliosis, and spongiform change were evident in the deeper cortical layers but were absent in the cerebellum. There was weak PrP immunostaining in the cortex and none in the cerebellum. DNA sequence analysis ruled out the presence of a pathogenic mutation in the coding region of the PrP gene and determined the codon 129 genotype as homozygous for methionine (MM). Western blot analysis confirmed the diagnosis of PSPr.

Conclusion: To our knowledge, this is the first description of PSPr in a case lacking clinically detectable dementia and advanced age at the time of death. This case report adds to the growing pathological spectrum of prion diseases.

Back to Top | Article Outline
87 Creutzfeldt-Jakob Disease E200K in Argentina

Christian Begue1, Carlos Romero2, Horacio Martinetto1, Marcelo Schultz1, Estefania Rojas1, Oscar Meichtry3, Gustavo Sevlever1, Manuel Somoza4, Ana Lia Taratuto5. 1Referral Center for CJD. Institute for Neurological Research; FLENI; 2Imaging Department, Institute for Neurological Research; FLENI; 3Imaging Clinic, Neuquen, Argentina; 4CJD Surveillance Committee, Buenos Aires, Argentina; 5CJD Referral Center, Institute for Neurological Research, FLENI

Creutzfeldt-Jakob disease (CJD) is mostly sporadic with a reported incidence of 1-1.5 per million/year. 5 to 15% of CJD patients are genetic due to mutations in PRNP gene. Familial and/or genetic E200K cases referred since 1983 to 2009 represent 15% of definite and probable CJD (38/258). In Chile, clusters of E200K CJD have been detected. Patients of Chilean origin (n = 35), ie. born in Chile or of Chilean descent, most of them from Patagonia region, represent 14% of CJD in Argentina (35/258). Seventeen of these patients had familial history consistent with CJD, and 28/35 cases had DNA available for study. We report clinical, neuropathological and molecular aspects of 38 patients with E200K representing 15% of our surveillance, 35 of Chilean origin and 3 non Chilean origin (two Jewish Sephardite and one with prominent insomnia whose ethnicity was undeterminable). From those of Chilean origin there were 11/14 definite cases and 17/18 probable with DNA available, other 4 were relatives of the former and 3 familial cases without DNA. PRNP codon 129 genotype and PrPsc immunoblot were performed in 11/14 definite cases for which frozen tissue was available. Of these 11 cases, 6 were PRNP codon 129MM, and 5 MV; all type 1. 15/17 probable cases were PRNP129 MM and 2/17 MV. Age at onset for the 35 E200K of Chilean origin was: 58 (mean), 34-80 years (range) and duration of disease: 7.5 (mean), 2-24 months (range). All resembled sporadic CJD, although insomnia at onset and dysesthesias have been reported in several cases. Typical EEG was seen in 16/26 cases, but only a few have more than one register performed. MRI, including FLAIR and DWI sequences in several cases showed basal ganglia high signal in 12/14. Cerebellum PrP immunostaining showed synaptic and plaque-like pattern in both PRNP129 MM and MV definite cases.

Back to Top | Article Outline
88 Heidenhain Variant of Sporadic Creutzfeldt-Jakob Disease With the Co-Occurrence of Two Different Types of Prion Protein

Ignazio Cali1, Gianfranco Puoti1, Janis Blevins1, Adeela Alizai2, Pierluigi Gambetti1. 1Case Western Reserve University; 2Temple University Hospital

Sporadic Creutzfeldt-Jacob disease (sCJD) is a rare neurodegenerative disorder classified into five distinct phenotypes based on i) the polymorphic methionine (M)/valine (V) genotype at codon 129, and ii) detection of either type 1 or type 2 of the protease-resistant prion protein (PrPres) (Parchi et al., Ann Neurol 1999; Gambetti et al., Br Med Bull 2003). Sporadic CJDMM1, the most common CJD subtype, is the only CJD subtype that includes the Heidenhain variant (HsCJD), a condition characterized by early and prominent visual deficits associated with the preferential involvement of the occipital cortex (Kropp et al., Arch Neurol 1999). The histopathological phenotype of HsCJD is indistinguishable from that of sCJDMM1. Recently, we described a group of sCJD cases identified as sCJDMM1-2 in which both PrPres types were found to co-exist in the same brain (Cali et al., Brain 2009). In the present study, we investigated whether the Heidenhain clinical phenotype is present in sCJDMM1-2. To date, the screening of clinical histories from 59 sCJDMM1-2 patients that were received at the National Prion Disease Pathology Surveillance Center between 1998 and 2009 has led to the identification of 8 (14%) HsCJDMM1-2 subjects. The detailed study of two HsCJDMM1-2 cases shows that the immunohistopathological features as well as PrPres type determined in different brain locations are consistent with the features of the sCJDMM1-2 subtype (Cali et al., Brain 2009). The visual cortex is severely affected in both cases and is found to carry both PrPres types (Kropp et al., Arch Neurol 1999). To our knowledge, this is the first finding of HsCJD in sCJDMM1-2 and indicates that the presence of even relatively large amounts of PrPres type 2 does not impede the expression of HsCJD. (Supported by, NIH AG-14359, CDC UR8/CCU515004 and Charles S. Britton Foundation; the CDC Foundation).

Back to Top | Article Outline

PLATFORM SESSION 6: PEDIATRIC NEUROPATHOLOGY

89 The Development of GABAergic Neurons in the Human Cerebral Cortex

Gang Xu1, Kevin Broadbelt1, Robin Haynes1, Natalia Borenstein1, Rebecca Folkerth2, Felicia Trachtenberg3, Joseph Volpe1, Hannah Kinney1. 1Children's Hospital Boston and Harvard Medical School, Boston MA; 2Brigham and Women's Hospital, Boston, MA; 3New England Research Institutes, Watertown, MA

During evolution, the number and complexity of GABAergic neurons have greatly increased in the human cerebral cortex, suggesting that GABAergic neurons are relevant to the sophisticated cognitive processing of humans. In this study, we postulated that the GABAergic system develops mainly after midgestation. The frontal (associative) cerebral cortex was studied in 19 human normative cases ranging in age from 23 gestational weeks to 2 postnatal years. The GABAergic neurons in the cortex were defined by GAD65/67 (biosynthetic enzyme for GABA) immunopositive neurons with a non-pyramidal morphology. The morphology of the GABAergic neurons changed from small, round neurons at 23 gestational weeks, to multipolar neurons at term and 3 postnatal months, and to the adult-like granular morphology thereafter. In the cortical laminae III-V, there was an increase in GABAergic neuronal density from midgestation to term, with a gradual decrease thereafter, as demonstrated by computer-based quantitative assessment and Loess curves. Western blotting of GAD65/67 further supported these cellular data. By immunocytochemical analysis of GABAA receptors a1 and a3 subunits, we found that both subunits were expressed by pyramidal neurons, particularly in Layer V, as well as granular neurons throughout all laminae. In a pilot receptor autoradiographic study using 3H-GABA binding to the GABAA receptors, we analyzed the frontal cortex of a fetus at 20 gestational weeks compared to the same region in an infant at 3 postnatal months. Standardization of the binding levels between these two cases indicated that GABAA receptor binding was markedly increased (83%) in the 3-month-old cortex compared to the fetal cortex. Additional samples are under study. These data support the hypothesis that the GABAergic system develops relatively late in gestation in the human cerebral cortex. They provide the foundation for the analysis of cortical GABAergic neurons in putative early disorders of cortical dysfunction, e.g., the encephalopathy of prematurity.

Back to Top | Article Outline
90 Id Proteins are Differentially Expressed in Medulloblastoma Tumor Cells and Endothelia

Christopher Pierson1, Andrew Snyder2, Ronald Houston3, Jordan Marshall2, Basil Kahwash2, Ashley Dulin-Smith2. 1Nationwide Children's Hospital and the Ohio State University; 2The Research Institute at Nationwide Children's Hospital; 3Department of Laboratory Medicine at Nationwide Children's Hospital

Inhibitor of DNA binding or inhibitor of differentiation (Id) proteins regulate many essential facets of tumor biology such as cell proliferation, differentiation, cell survival, angiogenesis, and invasion. Id expression is upregulated in a variety of malignant tumors and it is frequently associated with high-grade, poorly differentiated lesions, while differentiated tissues show little or no Id expression. The four Id genes are members of the helix-loop-helix (HLH) family of transcription factors that act as negative regulators of HLH complexes by binding and sequestering these complexes. We hypothesized that Id proteins are overexpressed in medulloblastoma (MB). We performed immunohistochemistry using the MB tissue microarray from the Cooperative Human Tissue Network, which contains 47 unique MB and 11 normal control cerebella and antibodies specific to Id1, Id2, Id3 and Id4. Overall staining scores were generated as the product of staining intensity (0, no staining to 4, most intense) and the proportion of cells stained (0, 0%; 1, 1 to 25%; 2, 26 to 50%; 3, 51 to 75%; 4, >76%). Id1 was not detected in normal cerebella or in MB cells, but 81% of tumors showed strong Id1 expression in tumor vessel endothelial nuclei. Id2 expression was scant in normal cerebella and increased in MB (median overall staining score: 4). Id3 expression was scant in normal cerebellum, but it was markedly upregulated in MB (median overall staining score: 12) and in tumor endothelial cells. Id4 was not expressed in normal cerebellum and MB tumor cells were essentially negative. Id2 and Id3 are upregulated in MB tumor cells whereas Id1 and Id3 are expressed in tumor vessels, but not in native vessels. Studies indicate that Id proteins maintain cells in an immature, highly proliferative state so Id protein dysregulation in MB may function to maintain tumors by promoting cell proliferation, survival and angiogenesis.

Back to Top | Article Outline
91 Cerebral White Matter Hypoxia and Antioxidant Therapy in Rats With Hydrocephalus

Marc Del Bigio1, Osaama Khan2, Terry Enno2, Luiza da Silva Lopes3. 1Pathology - University of Manitoba; 2University of Manitoba; 3Universidade de São Paulo

Hydrocephalus is associated with reduced blood flow in periventricular white matter. We hypothesized that the brains of young rats with hydrocephalus would exhibit cellular evidence of hypoxic and oxidative brain damage, as well as protective responses. Hydrocephalus was induced by injection of kaolin into the cisterna magna of 1-day and 21-day-old Sprague-Dawley rats. Ventricle size was assessed by magnetic resonance imaging (MRI). In situ evidence of tissue hypoxia was shown by pimonidazole hydrochloride binding in periventricular glial and endothelial cells. Biochemical assay of nitrite indicates increased nitric oxide production, and nitrotyrosine was detected by immunohistochemistry in white matter. Biochemical assay of thiobarbituric acid reaction and immunohistochemical detection of 4-hydroxy-2-nonenal in white matter indicates presence of lipid peroxidation. Neither catalase nor glutathione peroxidase activities were increased. We did not detect a change in hypoxia inducible factor 1a by quantitative RT-PCR. Cerebral vascular endothelial growth factor (VEGF) expression determined by quantitative RT-PCR and ELISA was not changed, although VEGF immunoreactivity was increased in reactive astrocytes of hydrocephalic white matter. Hydrocephalus was induced in a separate set of rats at 21 days age and they were given a mix of antioxidant agents daily by oral gavage between 35 and 49 days. No benefit was seen, although the ventricles were not severely enlarged and therefore the experiment will be repeated. To assess the role of neuronal nitric oxide synthase (nNOS), we induced hydrocephalus in 7-day-old nNOS knockout and wild type mice. Mutant mice exhibited reduced astroglial reaction despite comparable ventricle size at 14 days. We conclude that in rodent models of neonatal kaolin induced hydrocephalus, hypoxia in white matter might contribute to the destructive changes and that the cellular compensatory mechanisms might not be adequate. Dietary manipulations are worth investigation.

Back to Top | Article Outline
92 Cerebellar Hemorrhagic Injury in Premature Infants and its Associated Neuropathology: A Clinicopathologic Study of 18 Cases

Krista Smith1, Carl Boesel2, Anna Hughes2, Christopher Pierson3. 1The Research Institute at Nationwide Children's Hospital; 2Department of Laboratory Medicine at Nationwide Children's Hospital; 3Nationwide Children's Hospital and the Ohio State University

Cerebellar hemorrhagic injury (CHI) affects 10-25% of premature infants. Since most CHI autopsy studies predate the current era it is crucial to update our knowledge. We hypothesize that CHI does not occur in isolation, but rather, in association with additional neuropathology such as germinal matrix hemorrhage (GMH), intraventricular hemorrhage (IVH) and/or periventricular leukomalacia (PVL). We defined CHI as grossly and microscopically evident hemorrhagic injury occurring in cerebellar parenchyma, and reviewed all preterm infants (<37 weeks gestation) autopsied at our institution from 1999-2009. Eighteen cases meeting these criteria were identified. Mean gestational age was 24.3±2.5 weeks (range: 19.5-30.5); mean postnatal age was 2.5±2.4 weeks (range: 0-10). Chorioamnionitis (33%) and placental abruption (28%) were notable maternal factors. All 16 of the live born infants had respiratory distress syndrome. Seventy-five percent of all infants had a patent ductus arteriosus. Infections were common (sepsis 94%, necrotizing enterocolitis 39%, pneumonia 33%). A hematoma destroyed the caudal aspect of the cerebellum in 17 cases (94%) while 1 had multiple scattered hemorrhages. Bilateral hemispheric and vermal involvement was noted in 17 (94%) cases while 1 had unilateral hemispheric CHI. Eighty-three percent of cases had GMH 73% of which also had IVH. PVL occurred in 22% of cases. At autopsy CHI tends to be bilateral, in contrast to imaging studies where unilateral CHI predominates. The frequent association of CHI with GMH suggests that there may be overlapping risk factors or pathogenetic mechanisms. Cognitive abnormalities are common in survivors of prematurity and recent data suggests that the cerebellum has a role in such higher order functions. However, since additional, often severe, brain injury frequently coexists with CHI, discerning the role of CHI in neurodevelopmental outcome may be challenging. Further studies are needed to better understand the pathogenesis of CHI and to determine how CHI may contribute to neurodevelopmental outcome.

Back to Top | Article Outline
93 Ectopic Cerebellar Neurons in a Novel Tuberous Sclerosis Mouse Model

June Goto1, Spencer Tung2, David Kwiatkowski1, Harry Vinters2. 1Division of Translational Medicine, Brigham and Women's Hospital; 2David Geffen School of Medicine, UCLA

Tuberous sclerosis complex (TSC) is a multi-system disorder, in the course of which affected patients frequently develop seizures as a result of cortical tubers, regions of pronounced neuronal disorganization and neuroglial cytologic abnormalities. A mouse model of TSC showing neuronal loss of Tsc1 shows dysplastic neocortex with cytomegalic neurons, reduced myelination, seizure activity, and markedly reduced survival (Meikle et al, J Neuroscience 27:5546-5558, 2007). We have examined brains from a related but novel mouse model in which neuroprogenitor specific recombination and loss of Tsc1 is induced at embryonic day 13 (E13). These mice display a median survival of 37 days, with 15% surviving past 6 months of age. Immunohistochemical study of brains from these mice demonstrates neuronal disorganization and neuronal cytomegaly within both cerebral cortex and hippocampi. In addition, cells that are morphologically similar to cerebellar Purkinje cells and positive for phospho-S6 (S240-244) are abundantly present in the cerebellar molecular layer of these novel TSC mutant mice, while they are not seen in either wild type mice or the previously described neuronal model. Immunoreactivity for pS6 (S240-244) in the cerebellar molecular layer cells is significantly less in the older vs. the younger mice. (The cerebellum is only rarely the site of neuropathologic abnormalities in human TSC.) We conclude that neuronal migration and cytologic abnormalities are widespread in this mouse model, involving not only neocortex and hippocampus, but also the cerebellum. The model may have value in the study of mechanisms of both and aberrant neuronal/neuronal precursor migration.

Back to Top | Article Outline
94 Atypical Teratoid Rhabdoid Tumours at British Columbia Children's Hospital: "Cryptic cases" and Long-Term Survivors

Adam Fleming1, Diane Birks2, Stephen Yip3, Michael Handler2, B.K. Kleinschmidt-DeMasters4, Christopher Dunham5. 1BC Children's Hospital; 2Department of Neurosurgery, University of Colorado at Denver, CO; 3Department of Pathology, British Columbia Cancer Agency, Vancouver, BC; 4Departments of Pathology & Neurology, University of Colorado at Denver; 5Division of Anatomic Pathology, BC Children's Hospital, Vancouver BC

INI-1 immunohistochemistry (IHC) has recently facilitated the diagnosis of Atypical Teratoid Rhabdoid Tumours (ATRTs). Haberler C., et al. (2006) have espoused the existence of a subgroup of ATRTs with a paucity of rhabdoid cells (ie, "cryptic"). In this context, our initial goal was to retrospectively determine BCCH's experience with ATRT from 1986-2009 using INI-1 IHC. From 120 cases of primary malignant CNS neoplasia tested, 15 were INI-1 negative, 10 of which did not carry an initial diagnosis of ATRT (ie, "cryptic"). Aside from rhabdoid features, all 15 cases were clinicopathologically similar to those reported in the literature, although some important exceptions were noteworthy. Three long term survivors (range: 4-8 years) were identified, all from the "cryptic" group. Distinguishing features of these three cases were as follows. Case #1, a 9 y/o female originally diagnosed as "gliosarcoma", displayed a diffuse sarcomatoid architecture, a complex cytogenetic pattern (46 XX der(1) t(1;1)(p36;q23), del (6)(p21p24), -22[10]/46, XX[11]), and was the only patient treated with radiation and CCG945 chemotherapy. Cases #2 and #3 were both 1 y/o females originally diagnosed with "medulloblastoma"; case #2 carried a clinical diagnosis of NF2 and was the only patient treated with the COG 99703 protocol, while case #3 did not demonstrate any additional unique features. Secondarily, we set out to establish the biologic basis for these 3 favorable outcomes. Preliminary epigenetic analyses of MGMT, RASSF1A, MLH3, RUNC3, and HIC1 via methylation specific PCR have essentially failed to reveal any differentiating features. Recently, Birks D. et al. (2009) demonstrated the sensitive and specific overexpression of claudin-6 in ATRTs. Accordingly, IHC staining of our 15 cases revealed positivity in 11. Interestingly, three of the four claudin-6 negative cases were long term survivors. Our results reiterate the existence of "cryptic" ATRTs and suggest that claudin-6 negativity may mark a prognostically favorable cohort.

Back to Top | Article Outline
95 Moderate Intermittent Hypoxia Protects Neurodevelopment in Newborn Mice

Homa Adle-Biassette1, Myriam Bouslama2, Boris Matrot2, Geraldine Favrais2, Pierre Gressens2, Jorge Gallego2. 1INSERM; 2INSERM U676

Apnea of prematurity and resultant intermittent hypoxic episodes are present in practically all preterm infants under 35 weeks of gestational age. Apnea is correlated with neurodevelopment disorders but evidence of causality is lacking. Animal studies showed that relatively stringent intermittent hypoxic episodes disrupted brain development and cognitive abilities. However, previous animal studies also showed that mild hypoxic preconditioning protected the brain against hypoxic-ischemic injuries. Here, we examined whether moderate intermittent hypoxia akin to those experienced during apneas may protect newborn's brain development and function. The study was conducted in newborn mice episodically separated from their mother, a condition common to many preterm infants and known to impair neurodevelopment. This effect was confirmed here: newborn mice separated from their mothers 6 hours per day from postnatal day 6 to postnatal day 10, showed poor memory score at adolescence. However, exposure to moderate intermittent hypoxia during separation periods restored normal memory scores. Furthermore, newborn mice with ibotenate-induced, excitotoxic brain lesions similar to those observed in preterm infants had smaller lesions after intermittent hypoxia, and better memory scores, compared to controls. The protective effects of intermittent hypoxia were associated with increased BDNF and VEGF production and increased neurogenesis in the hippocampus. The neuroprotective effects of apnea-like, intermittent hypoxia on development were not previously described. The elucidation of their mechanisms may lead to useful therapeutic strategies to prevent developmental disorders in preterm infants.

Back to Top | Article Outline
96 Distribution of Beta 4 Tubulin-Positive Cells During Human Brain Development

Angeliki Nikolakopoulou1, Susan Staugaitis2, Ansi Chang2, Bruce Trapp2. 1Mount Sinai School of Medicine; 2Cleveland Clinic

We recently reported a population of cells in the subventricular zone (SVZ) of human and rodent brain that expresses beta 4 tubulin (BT4) and has properties of primitive neuroectodermal cells (Wu et al., J Neurosci 2009; 29:7649-7657). This study describes the temporal distribution and phenotype of BT4-positive cells during human brain development. Tissue from 19 brains ranging from 17 weeks post conception (wpc) to 31 months post natal were examined. Detailed quantitative analysis was performed on sections from caudothalamic junction and posterior parietal lobe from 8 and 6 brains, respectively. In every region examined, BT4 immunoreactivity was first identified in immature ventricular zone (VZ) cells. A few cells were present in the thalamus and subcallosal VZ at 17 wpc. Their number increased until nearly all VZ cells labeled. As VZ BT4 cells increased, BT4-positive cells appeared in the SVZ. At 30 wpc, BT4 cells were present in the SVZ of the thalamus, caudate nucleus, and corpus callosum, but not in the SVZ of the posterior parietal lobe. SVZ BT4 cells peaked in the full term brain. Their number relative to SVZ nuclear density increased up to 18 fold in the 31 month brain. BT4 immunoreactivity was also observed in periventricular oligodendrocytes. The SVZ BT4 cells could be distinguished from oligodendrocytes by location and morphology. BT4 positive oligodendrocytes were Olig2-positive, but the SVZ cells were not. Double labeling showed that BT4-positive SVZ cells did not express NG2, O4, PLP, GFAP, PSA-NCAM, or Tuj1. Rare BT4-positive VZ cells expressed the Ki-67 proliferation antigen, but no labeling of BT4 SVZ cells was observed. The number and distribution of BT4 SVZ cells during development correlate with the period when most neurogenesis has ceased and gliogenesis peaks. Studies of transgenic mice are in progress to directly examine the fate of SVZ BT4 cells.

Back to Top | Article Outline

PLATFORM SESSION 7: NEUROPATHOLOGY - MISCELLANEOUS

97 Polymyositis Associated With Metastatic Thymomas: Report of Two Cases

Jodi Carter1, Zaeem Siddiqi2, Jian-Qiang Lu3. 1Department of Laboratory Medicine and Pathology, University of Alberta; 2Divsion of Neurology, University of Alberta; 3University of Alberta

Benign thymomas are frequently associated with paraneoplastic autoimmune diseases, particularly myasthenia gravis (MG), and less commonly polymyositis. In contrast, few cases of thymic carcinomas or metastatic thymomas co-existing with polymyositis have been described. We report two patients with stage IV (metastatic) thymoma associated with polymyositis.

Case 1: An 18-year-old female was diagnosed with sero-positive MG in the setting of an anterior mediastinal mass. Metastases to the lungs were subsequently found on CT scans. Biopsies of the mass, pericardium and pleura demonstrated pleomorphic epithelial cells admixed with lymphocytes, consistent with a lymphocyte-rich thymoma. She developed left diaphragmatic paralysis due to phrenic nerve compression by metastatic thymoma. Her treatment included chemotherapy, surgical resection and post-operative radiotherapy leading to remission. Three years later thymoma recurred for which she underwent another resection. Mild MG symptoms briefly recurred but went into remission with treatment. Five years later, she developed progressive weakness of pharyngeal muscles and right diaphragm requiring mechanical ventilation and nasogastric feeding. Electrophysiologic studies showed a diffuse and necrotizing myopathy with no evidence of MG recurrence. A biceps muscle biopsy showed morphological and immunohistochemical features typical for polymyositis.

Case 2: A 45-year-old female developed sero-positive MG, which went into remission after immunotherapy. Four years later she was found to have a mediastinal mass that was diagnosed as thymoma with metastases to the pleura and lungs. She received aggressive chemotherapy. Two years later, she developed respiratory failure and diffuse myopathy affecting the limbs and diaphragm. A vastus lateralis muscle biopsy exhibited the diagnostic features of polymyositis. In both patients, the polymyositis occurred after the metastases of thymoma. Although both patients initially had MG along with thymoma, neither had clinically active MG around the time of polymyositis. This study suggests that the pathogenesis of metastatic thymoma-associated polymyositis likely differs from that of thymoma-associated MG.

Back to Top | Article Outline
98 Alcohol-Related Peripheral Neuropathy-Characterization in an Experimental Animal Model

VanAnh Nguyen1, Michelle Mellion1, Ming Tong1, James Gilchrist1, Suzanne de la Monte2. 1Rhode Island Hospital-Warren Alpert Medical School of Brown University; 2Rhode Island Hospital

Alcohol-related polyneuropathy (ALPN) is a chronic disease afflicting up to 66% of drinkers. ALPN causes significant morbidity due to weakness, sensory loss, incontinence, and disability, yet its pathogenesis remains poorly understood. Enthusiasm regarding the role of thiamine deficiency has waned due to disappointing clinical trials assessing thiamine treatment effects. Our hypothesis is that like alcohol-related liver and brain degeneration, ALPN is mediated by combined effects of insulin and IGF resistance and oxidative stress. We utilized an established experimental model in which adult male rats were pair-fed for 8 weeks with isocaloric liquid diets containing 0% (N = 24) or 37% (N = 22) ethanol by caloric content. Nerve conduction studies (NCS) were performed and peripheral nerve tissue was analyzed using semi-thin sections, ELISAs, and PCR. Chronic alcohol feeding significantly slowed motor nerve conduction velocities in both tibial (P = 2.3E-10) and peroneal (P = 2.3E-08) nerves. Conduction velocity remained intact in sensory nerves, and amplitudes in general were not altered. Tissue studies revealed demyelination of motor and mixed nerves, early denervation myopathy, and reduced mean myofiber diameter (gastrocnemius muscle; P < 00001) in ethanol-fed rats. PCR analysis revealed significantly reduced mRNA levels of insulin, IGF-1, IGF-2, IGF-1 receptor, IRS1, and IRS2 in the ethanol group. ELISAs demonstrated up-regulated expression of insulin and IGF-1 receptors, IRS-1, and ubiquitin, and reduced expression of myelin-associated glycoprotein and tau in peripheral nerves of alcohol-fed rats (all P < 0.05 or better). Together, these results suggest that ethanol exposure has direct neurotoxic effects on peripheral nerves despite adequate nutrition and that ALPN is characterized by 1) slowed conduction velocities with mainly demyelination, but some degree of axonal degeneration as well; 2) impaired expression of genes regulating insulin and IGF signaling pathways; 3) increased insulin and IGF resistance; and 4) loss or degeneration of myelin and axonal cytoskeletal proteins in peripheral nerve tissue.

Back to Top | Article Outline
99 Glial-Vascular Degeneration in CADASIL

Thea Brennan-Krohn1, Stephen Salloway2, Stephen Correia3, Matthew Dong4, Suzanne de la Monte5. 1Rhode Island Hospital; 2Butler Hospital and the Warren Alpert Medical School-Brown University; 3Veterans Affairs Medical Center and Alpert Medical School at Brown; 4Brown University; 5Rhode Island Hospital-Warren Alpert Medical School of Brown University

Background: CADASIL is a genetic vascular dementia caused by mutations in the NOTCH3 gene on Chromosome 19. However, little is known about the mechanisms of vascular degeneration.

Methods: We characterized upstream components of Notch signaling pathways that may be disrupted in CADASIL, by measuring expression of insulin, IGF-1, and IGF-2 receptors, Notch 1, NOTCH3, and aspartyl-(asparaginyl)-β-hydroxylase (AAH) in cortex and white matter from 3 CADASIL and 6 control brains. We assessed CADASIL-associated cell loss by measuring mRNA corresponding to neurons, oligodendroglia, and astrocytes, and indices of vascular degeneration by measuring smooth muscle actin (SMA) and endothelin-1 (ET-1) expression in isolated vessels. Immunohistochemical staining was used to assess SMA degeneration.

Results: Significant abnormalities including reduced cerebral white matter mRNA levels of Notch 1, NOTCH3, AAH, SMA, IGF receptors, myelin-associated glycoproteins, and glial fibrillary acidic protein, and reduced vascular expression of SMA, IGF receptors, Notch 1 and NOTCH3 were detected in CADASIL-lesioned brains. In addition, we found CADASIL-associated reductions in SMA, and increases in ubiquitin immunoreactivity in the media of white matter and meningeal vessels. No abnormalities in gene expression or immunoreactivity were observed in CADASIL cerebral cortex.

Conclusions: Molecular abnormalities in CADASIL are restricted to white matter and white matter vessels, corresponding to the distribution of neuropathological lesions. The findings demonstrate evidence of both vascular and glial degeneration with reduced expression of IGF receptors and AAH, which regulate Notch expression and function.

Back to Top | Article Outline
100 Degos Disease Involving the CNS: Report of a Case and Review of the Literature

Stephen Coons1, Sandipan Pati2. 1Barrow Neurological Institute; 2St. Joseph's Hospital and Medical Center

A 41 year-old physics professor with recent onset CNS symptoms reflecting widespread white matter disease was transferred to our institution after he underwent left frontal lobe biopsy that was non-diagnostic and left him aphasic. He also presented with with non-healing skin ulcers and was on dialysis for renal failure. Review of the biopsy and additional special stains showed cortical gray and subcortical white matter with normal architecture and cellularity. Thickened microvessels were seen focally and found to be PAS positive but with normal smooth muscle complement and negative for Beta-amyloid. Only modest reactive changes were seen in the surrounding white matter and comparison with the MRI suggested the biopsy was superficial to the significant disease. A skin biopsy of the papular rash was obtained. This showed similar but more severe vascular thickening in the deep dermis. A diagnosis of Degos' disease (malignant atrophic papullosis) was made. This rare disease is a microangiopathy affecting skin, systemic organs and, less commonly, the CNS, in which there is deposition of fibrillary material between the endothelium and internal elastic lamina.

Back to Top | Article Outline
101 A 20 year Retrospective Review of Traumatic Spinal Cord Injuries at a Statewide Medical Examiner's Office

Cecilia Wu, Sarah Lathrop, R. Ross Reichard. Office of the Medical Investigator, University of New Mexico

Background: In the United States approximately 250,000 persons have a spinal cord injury (SCI) and most will die from complications related to their injury. Analyzing trends in SCI and related medical complications can identify areas of potential medical intervention and generate data that may be clinically useful in predicting long-term outcomes.

Methods: In order to examine trends and patterns of traumatic SCI deaths in New Mexico we queried our electronic database for deaths meeting case inclusion criteria from 1989 to 2008.

Results: We identified 305 cases, of which 81% were males and 19% were females. Race/ethnicity generally followed the distribution of the New Mexican population and the mean age at death did not differ significantly between genders (53 years). The manner of death was listed as accident (80%), homicide (7%), natural (7%), suicide (4%) or undetermined (2%). The most common mechanisms of spinal cord injury were motor vehicle accidents (42.6%), fall from a standing height (12.8%), fall from above a standing height (9.2%), gunshot wounds (8.8%), diving accidents (4.6%) and motorcycle accidents (4.6%). Males tended to survive longer than females, and survival time was significantly (P < 0.0001) associated with extent of injury (complete quadriplegics had a mean survival time of 6.9 years versus 16.8 for paraplegics), manner of death (p = 0.03) and age at injury (p < 0.0001), with a mean survival time of 24.3 years for those injured before age 18 compared to 2.0 years for those injured after age 60. Mean survival time following SCI significantly increased over the past 20 years (p = 0.0002).

Conclusions: Analyzing patterns of deaths due to traumatic SCI in a state-wide medical examiner's office provides excellent epidemiological data for SCI researchers, a context for neuropathologists involved in evaluation of SCI neuropathology and a foundation for additional investigations into SCI.

Back to Top | Article Outline
102 Causes of Death and Neuropathology in Autism Spectrum Disorder: A Medical Examiner Perspective

Kenneth Hutchins1, Mariana Nunez2, Carol Petito2. 1Miami Dade County Medical Examiner Department; 2University of Miami Miller School of Medicine, Department of Pathology

Autism Spectrum Disorder (ASD) is characterized by abnormalities in how patients relate to and communicate with others and their environment. It develops in as many as 1 in 150 children and may be associated with co-morbid disorders including seizures and mental retardation. Because ASD reduces life expectancies, we reviewed autopsy records of 22 consecutive cases from two south Florida Medical Examiner Departments over a 10 year period and correlated cause of death (COD) with clinical history and neuropathology. Patient ages averaged 18±11 yrs and ranged from 3-51 years; 16 were male and 11 were children <18 yrs. 13 were white and 9 were black. Associated disorders included seizures in 6, mental retardation in 2 and one each with Down Syndrome (DS) or schizophrenia. 73% of cases had ASD-related CODs that included accidental drowning in 5, seizures in 4, asphyxia or adverse drug reactions in 3 each, and suicide in 2. Non-ASD CODs included infections (2), passengers in car accidents (2) and coronary artery disease. 5 of 11 children suffered accidental drowning in lakes or ponds, 2 had seizures and one each suffered an adverse drug reaction, MVA, food aspiration or infection. The average brain weight of the adults between 18 and 51 yrs. was 1266±130 g, exclusive of three with brain edema, and of children between 6 and 12 yrs. was 1344±93 g. Pathology changes included gyral pattern of DS, microcephaly, hippocampal or cerebellar atrophy, acute meningitis and hypoxic-ischemic encephalopathy. These results are consistent with prior studies showing that common CODs in this patient population are seizures and accidents such as asphyxia and drowning. They suggest that drowning and suicide in ASD patients are age-related whereas seizure-related deaths are not. We also found a trend for decreased brain weight in adults with ASD as compared with children with ASD.

Back to Top | Article Outline
103 The Mtm1C205T Knock-In Mouse: A New Model of Myotubular Myopathy With a Mild Phenotype

Christopher Pierson1, Ashley Dulin-Smith2, Kristen Roth2, Morgan Marshall2, Nada Naiyer2, Jordan Marshall2, Andrew Snyder2, Jordan Gladman2, Dawn Chandler2, Alan Beggs3. 1Nationwide Children's Hospital and the Ohio State University; 2The Research Institute at Nationwide Children's Hospital; 3Children's Hospital Boston

MTM1 mutations cause myotubular myopathy (MTM) an X-linked centronuclear myopathy. MTM1 encodes the lipid phosphatase myotubularin. The Mtm1 knockout mouse is it an excellent disease model, but its short life span (<6 weeks) limits the scope of pre-clinical trials that can be performed. To address this issue we sought to generate an MTM model with a milder phenotype. Based on data from human genotype-phenotype correlation studies we chose to model the C205T point mutation, which generates the R69C missense change in a catalytically inactive myotubularin domain. We predicted that a hypofunctional protein would result. Knock-in mice appear unaffected at birth, but by 2 months they have less body mass (15.8±1.3 gm) than wild type (21.2±2.7 gm) (p < 0.001). Knock-in body mass remains approximately half that of wild type between 3 and 12 months. Knock-in mice generate less grip strength force (0.07±0.008 kg) than wild type (0.1±0.02 kg) (p < 0.001) at 2 months and grip strength is persistently 60% to 70% that of wild type between 3 and 12 months. Fifty percent of affected mice live 50 weeks, and death is likely due to respiratory compromise. Histopathology is in keeping with MTM as the myofibers are small and many show centrally placed nuclei. Immunofluorescence staining shows perturbations in the localization of internal membrane proteins in many myofibers. Unexpectedly, introducing C205T disrupts splicing, by inappropriately excluding exon 4 in most mRNAs, and no myotubularin protein is detectable in immunoblots. However, a small amount of full length mRNA that contains the introduced mutation is present, and this may provide enough residual functional myotubularin to account for the relatively mild phenotype. The Mtm1C205T mouse is an excellent model of MTM and its milder phenotype makes it an ideal complement to the severe Mtm1 knockout mouse in pre-clinical trials.

Back to Top | Article Outline
104 Choroidal Findings in Neurofibromatosis Type 1 (NF1)

Caterina Giannini1, Fausto Rodriguez2, Charles Eberhart3, Diva Salomão2. 1Mayo Clinic College of Medicine; 2Mayo Clinic; 3The Johns Hopkins Hospital

Iris involvement in patients with NF1 is common, however, choroidal involvement is considered rare. Choroidal neurofibroma (NF) and ganglioneuroma have been reported. We report the choroidal findings of 4 NF1 patients. Two were surgically enucleated eyes: a 39-year-old woman undergoing plastic surgery for massive facial NF and a 3 year-old girl with congenital glaucoma and a large retro-orbital NF. Three were autopsy eyes from 2 NF1 patients without known ocular clinical manifestations. Both surgical eyes disclosed diffuse neurofibromatous proliferation largely composed of Schwann cells, spindle shaped melanocytes and numerous ganglion cells isolated and in clusters, causing marked diffuse thickening of the choroid, ciliary body (both cases) and iris (one case). One case showed prominent tactoid-like bodies. The 2 autopsy cases did not show distinct choroidal abnormalities. It is still unclear if this process involving the choroid represents a hamartomatous or a neoplasm, since all the components observed, nerve fibers, melanocytes and ganglion cells are normal components of the choroid.

Back to Top | Article Outline

PLATFORM SESSION 8: TUMORS - NONGLIAL

105 MicroRNA-9 and MicroRNA-200a Differentiate CNS Hemangioblastomas from CNS Metastatic Clear Cell Renal Cell Carcinomas

Sriram Venneti1, Aihua Liu2, John Tobias2, Donald Baldwin2, Alexander Judkins2, Zissimos Mourelatos2, Priti Lal2. 1Dept of Pathology, University of Pennsylvania; 2University of Pennsylvania

Hemangioblastomas and metastatic clear cell renal cell carcinomas in the CNS occur as part of von Hipple-Lindau syndrome and show similar histopathologic features. The distinction of these two entities is of prognostic significance as hemangioblastomas are relatively benign and treated with surgical resection while metastatic renal cell carcinomas are treated aggressively. Immunohistochemical markers currently used do not unequivocally differentiate between these two tumors. Further, the biology of hemangioblastomas is not completely understood. To determine novel markers that differentiate these two conditions, we hypothesized that microRNA profiling of these two tumors will help identify unique microRNAs to each of these conditions. We obtained formalin fixed paraffin embedded tissue from 10 cases each of hemangioblastomas, CNS metastatic renal cell carcinomas and primary clear cell renal cell carcinomas. Total RNA was extracted from each of these cases and microRNAs were labeled with Exiqon miRCURY LNA™ microRNA Power Labeling Kit. Labeled RNA was then hybridized to a glass slide microarray containing 2000 synthetic microRNA probes enabling simultaneous profiling of multiple microRNAs. We found 10 microRNAs increased and 39 microRNAs decreased more than 3 fold in hemangioblastomas compared to CNS metastatic renal cell carcinomas. Of these, microRNA-9 was increased 9-fold (p < 0.001) and microRNA-200a was decreased 22-fold (p < 0.0001) in hemangioblastomas compared to CNS metastatic clear cell renal cell carcinoma. These microRNAs did not differ significantly between primary and CNS metastatic clear cell renal cell carcinoma. Quantitative real time RTPCR confirmed these results with a 27-fold increase in microRNA 9 (p < 0.001) and a 4-fold decrease in microRNA-200a (p < 0.001) in hemangioblastomas compared to CNS metastatic clear cell renal cell carcinomas. Our data suggest that these microRNAs may be of value in the diagnosis of hemangioblastomas and help understand the biology of these tumors.

Back to Top | Article Outline
106 BCL-6 Gene Abnormalities are Common in Primary Central Nervous System Diffuse Large B-Cell Lymphoma

Sarah Martin1, Magdalena Czader2, Mousa Al-Abbadi3, Ryan Stohler4, Gail Vance4, Eyas Hattab2. 1Indiana University School of Medicine, Department of Pathology; 2Indiana University School of Medicine, Dept. of Path. and Lab. Med.; 3Dept of Pathology, James H. Quillen VA Med. Center, Mountain Home, TN; 4Indiana U. School of Medicine, Dept. of Medical and Molec. Genetics

Primary central nervous system lymphomas (PCNSL) are rare neoplasms characterized by a dismal prognosis. Emerging consensus suggests that these lymphoid neoplasms arise from lymphoid cells at the post-germinal center stage of differentiation. However, the majority of the cases of PCNSL of the diffuse large B-cell type are positive for BCL-6, a marker selectively expressed by germinal center B cells, and in limited studies, were shown to harbor BCL-6 gene rearrangements. We studied the incidence of BCL-6 gene rearrangements in 22 cases of well characterized PCNSL. Immunohistochemical stains for CD10, BCL-6 and MUM-1 were used to determine germinal center vs. postgerminal center cell origin. In-situ hybridization for EBER and fluorescence in-situ hybridization for BCL-6, MYC/IGH and IGH/BCL2 were performed. Survival was calculated using a Kaplan-Meier method. None of the patients were known to be HIV positive. Eighteen cases were of postgerminal center-cell phenotype. BCL-6 immunostain was positive in 20 cases. Only one case was positive for EBER, with 95% of cases not showing EBER hybridization. Eight cases (36%) showed rearrangements of BCL-6 gene. An additional three cases showed numerical abnormalities of BCL-6 (2 monosomy and 1 trisomy). The remaining 11 cases had normal BCL-6 signal. The majority of cases with BCL-6 rearrangement lacked MYC/IGH and IGH/BCL2 translocations with only one being positive for IgH/BCL-2 fusion. Two cases with rearranged BCL-6 showed trisomy/tetrasomy of BCL-2 gene, and one showed evidence of genomic instability with trisomy/tetrasomy for all studied probes. In conclusion, the majority of cases were of post-germinal center cell origin and were EBV negative. A high incidence of abnormalities of the BCL-6 gene was detected. Preliminary survival analysis showed no significant survival advantage in cases with normal BCL-6 genes. Additional cases are currently being studied.

Back to Top | Article Outline
107 Epstein-Barr Virus-Associated Primary Central Nervous System Lymphomas in Immunocompetent Elderly Patients

Yasuo Sugita, Daisuke Niino, Fumiko Arakawa, Koichi Ohshima. Department of Pathology, Kurume University School of Medicine

Epstein-Barr virus (EBV) has been implicated in the pathogenesis of primary central nervous system lymphomas (PCNSLs) in immunocompetent hosts. To investigate the role of EBV in the pathogenesis of PCNSLs in immunocompetent hosts, the present study assessed 6 PCNSL cases (elderly male immunocompetent patients; age > 60 years) histologically and immunohistochemically, and an EBV genetic study was performed. Histologically, all cases were diagnosed as diffuse large B-cell lymphomas with extensive necrosis. In all 6 cases, PCNSL cells were immunohistochemically positive for latent membrane protein 1 (LMP-1) and Epstein-Barr nuclear 2 (EBNA2). Atypical lymphoid infiltrate also showed positive signals for EBV-encoded small RNAs (EBERs) by in situ hybridization. EBV subtyping-PCR analysis demonstrated that 1 case was EBNA type 2B and the other 5 cases were EBNA type 2A, while 2 cases were EBV wild-type and 4 cases showed a 30-bp LMP-1 deletion by 30-bp LMP-1 deletion-PCR analysis. With regard to prognosis, 3 of the EBV-positive PCNSLs in the present study had a poor outcome. It is possible that LMP gene deletion, or EBNA-2 strain type, played a role in this outcome. In addition, EB-positive PCNSLs occurred in immunocompetent patients, arising in elderly patients (age > 60 years) without predisposing immunodeficiencies, thus suggesting that this disease also has a relationship with immunologic deterioration derived from the aging process.

Back to Top | Article Outline
108 Expression of SALL4 and LIN28 by Malignant Rhabdoid Tumors of the Central Nervous System

Jeremy Deisch1, Dinesh Rakheja2, Kimmo Hatanpaa1, Christa Hladik1, Emily Herndon1, Dennis Burns1, Charles White1, Jack Raisanen1. 1University of Texas Southwestern Medical Center; 2Children's Medical Center Dallas, Texas

Malignant rhabdoid tumors (MRTs) of the central nervous system (CNS) are highly aggressive neoplasms that usually occur in the posterior fossa of young children. MRTs are characterized by large cells with abundant cytoplasm and paranuclear inclusions, frequent expression of keratin, EMA, and SMA, and deletions and/or mutations of the SMARCB1/INI1 gene with absence of the protein product. Nevertheless, diagnosis may be difficult. Sometimes, large cells are missing, antigens are undetectable, tissue is not available for genetic analysis, or studies are not confirmatory and stains to detect the INI1gene product are equivocal. We used immunohistochemistry to assess expression of the stem cell transcription factor SALL4 and the RNA binding protein LIN28, markers of primitive germ cell tumors, in 11 intracranial MRTs and 113 other CNS lesions. We examined expression in 21 germinomas, 7 teratomas, 3 choriocarcinomas, one embryonal carcinoma, 30 gliomas, 13 medulloblastomas, 5 pituitary adenomas, 5 craniopharyngiomas, 7 pineal parenchymal neoplasms, 5 meningiomas, 5 primary CNS lymphomas, 5 metastatic carcinomas, 2 cases of intracranial sarcoidosis, 1 of Langerhans cell histiocytosis, and 3 sellar region inflammatory lesions. SALL4 was expressed by neoplastic cells in 9 of 11 MRTs and LIN28 in 7 of 11. Either SALL4 or LIN28 was expressed in 10 of 11. SALL4 and LIN28 were expressed by all germinomas, choriocarcinomas, and the embryonal carcinoma. The findings indicate that SALL4 and LIN28 are expressed by cells of most CNS MRTs. SALL4 and LIN28 are also expressed by poorly differentiated germ cell neoplasms but not other CNS neoplasms or inflammatory lesions. Immunohistochemistry to detect expression of SALL4 and LIN28 may aid in the diagnosis of intracranial malignant rhabdoid tumors.

Back to Top | Article Outline
109 Prox1 Protein of Prospero-Related Homeobox Gene in Meningiomas and Adult CNS

Roy Rhodes, Eric Richfield. Robert Wood Johnson Medical School

Lymphatic markers have been found in meningiomas, but not Prox1, a DNA-binding protein affecting cell fate and cell cycle exit in developing CNS and other organs. Its gene is in many pathways with upstream and downstream influences. In tumors Prox1 can have DNA or RNA mutations or possibly be affected only by upstream and downstream signals. The Drosophila homologue Pros directs glial or neuronal phenotype in neural progenitor cells, similar to Prox1 in vertebrates. In mitosis Pros exits the nucleus, locates near plasma membrane, incorporates into only one daughter cell for an asymmetric mitosis, allowing different genetic directions (i.e., glial or neuronal), and then returns to cytoplasm and then the interphase nucleus to direct cell fate. Nuclear Pros is prepositioned in fly glia where it keeps them immature, in G1 arrest, and immediately available for mitosis and signalling after injury. We find no Prox1 data on human arachnoid cells or meningiomas. Paraffin sections were stained with rabbit anti-human Prox1 in 12 meningiomas and normal adult CNS. Lymph node was a positive control. Some arachnoid cells had cytoplasmic but no nuclear Prox1, as did choroid plexus epithelium, ependymal cells, subependymal cells (some with the appearance of migrating progenitors) and subpial glia limitans. Scattered cortical and white matter glial cells and dentate gyrus granule cells had nuclear stain. Meningiomas (transitional, chordoid, oncocytic) had 1+ to 2+ cytoplasmic staining, with focal 3+ cells (3 point scale); many nuclei had small foci of nuclear stain. Recurrences had variable changes. Cytoplasmic Prox1 is demonstrated here in novel locations in human CNS and meningiomas. What is its purpose? Is Prox1 prepositioned for downstream nuclear target control? Could it alter genetic direction (meningioma metaplasia)? Is it a preparation for response to injury without prognostic implication? Is it in meningiomas due to different signalling than in normal CNS?

Back to Top | Article Outline
110 Transforming Growth Factor B Receptor Expression in Higher Grade Meningiomas.

Mahlon Johnson1, Aubie Shaw2, Mary O'Connell3, Fraser Sim4, Harold Moses5. 1Univ. of Rochester School of Medicine; 2Dept. of Cancer Biology, Vanderbilt Ingram Cancer Center, Vanderbilt U; 3Dept. of Pathology Univ. of Rochester School of Medicine, Rochester, N; 4University of Buffalo, Buffalo, NY; 5Dept. of Cancer Biology, Vanderbilt Ingram, Cancer Center, Vanderbilt

TGF-B receptors inhibit growth of many cell types including and some lower grade tumors. TGF-B effects are transduced through binding to the TGF-B type 2 receptor (TGF-B R2) that then complexes with the TGF-B type 1 receptor phosphorylating and activating its serine/threonine kinase. Expression and the role of TGF-B receptors in WHO grade II and III meningioma proliferation has not been studied. Real time PCR found no statistically significant difference in TGF-B R1, TGF-B R2, TGF-B R3 and Smad 7 RNA expression in WHO grade I, II and III meningiomas although TGF-B R3 expression was lower in grade III compared to grade I tumors (p = 0.0666). By western blot analysis, TGF-B R1 was detected in 16, 20, 22, 23 week fetal and one adult leptomeningeal sample, all 18 WHO grade I meningiomas, 14 grade II and 3 grade III meningiomas. TGF-BR2 was detected in none of the leptomeningeal samples, 55% of grade I meningiomas, 71% of grade II and none of 3 grade III meningiomas analyzed. Strong TGF-BR3 was detected in 94% of grade I and 70% of grade II (weak in 30%), and all 3 grade III tumors. Phospho-Smad 3 and Smad 7 were detected in nearly all grade I, II and III tumors. TGF-B1 (10ng/ml) treatment of cells had no effect on basal cell proliferation in all 7 grade II and the grade III meningioma cells at 72 hrs based on CyQUANT DNA analysis. TGF-B1 significantly reduced PDGF-BB stimulation of DNA synthesis in 22 wk fetal leptomeninges and 1 of 2 grade I meningiomas but had no effect on PDGF-BB stimulation in 6 grade II and the grade III meningioma while blocking PDGF-BB stimulation in 1 grade II meningioma. These findings raise the possibility of attenuated TGFB receptor expression and growth regulation in some higher meningiomas.

Back to Top | Article Outline
111 Malignant Transformation of Intracranial Meningeal Melanocytoma. Case Report and Review of the Literature

Fulin Wang, Xin Lou, Guangyu Qiao, Xin Song. Chinese PLA general hospital

Meningeal melanocytoma is an uncommon pigmented neoplasm that affects the CNS. Here we report an extremely rare case of malignant transformation of intracranial supratentorial melanocytoma within a short time. A 32-year-old man presented with history of a headache for five months. The neurological examination was normal. On MRI, the mass measuring 6 cm in diameter showed as an inhomogeneous bright on T1- and dark on T2-WI in the right temporal lobe. The patient underwent gross total removal of the tumor in 2006. The surgical specimens were soft and appeared to be deeply pigmented on the cut surface portion. The histological findings showed a highly cellular lesion composed of monomorphic cells with epithelioid features and heavily melanin-laden that tested positive for HMB-45 and S-100 and negative for cytokeratin. The histological diagnosis was consistent with a meningeal melanocytoma. An extensive workup failed to find evidence of any other primary site. The patient received no further treatment. The postoperative course was uneventful. After three years, an additional operation was performed in 2009 because the tumor was local recurrence with intracranial spread. The main mass was subtotally excised by right temporal craniotomy. Histological examination revealed epithelial and significant anaplastic changes, numerous atypical mitotic figures, and the MIB-1 indices were greater than 25% led to the diagnosis of a primary malignant melanoma originating from the prior melanocytoma. This case and cases from the literature demonstrate that the biological behavior of melanocytoma is uncertain and that these lesions may recur and transform into malignant melanoma.

Back to Top | Article Outline
112 Carcinoma, Metastatic to Intracranial Meningioma - Unusual Pattern of Metastasis

Patricia Moody1, Kevin Murtagh2, Sarat Piduru2, Steven Brem3, Reed Murtagh3, Amyn Rojiani3. 1Department of Pathology and Cell Biology, University of South Florida; 2College of Medicine, University of South Florida; 3Moffitt Cancer Center, University of South Florida

The phenomenon of tumor-to-tumor metastasis has been reported in the literature for over a century. However, it remains fairly uncommon with fewer than 100 cases being described during that time. Virtually any benign or malignant tumor can be a recipient, but meningiomas have been implicated as the most common intracranial neoplasm to harbor metastasis. The donor neoplasm is most frequently lung or breast carcinoma, while rare cases of metastasis from other primary tumors have been reported. We report here three examples of such metastases. Case 1: A 77-year-old male initially diagnosed via colonoscopy and biopsy with poorly differentiated rectal adenocarcinoma. Approximately one year later, the patient returned with a mass on his calvarium, short term memory loss, and difficulty speaking. MR imaging of the brain showed multiple intracranial lesions. Following surgery, the lesions were diagnosed as a meningioma, a metastatic adenocarcinoma and a meningioma with metastatic adenocarcinoma. Case 2: 58 year old with a remote history of prostate carcinoma, presented with dizziness and memory changes. A frontal lesion was identified on imaging. Surgical pathology revealed the tumor was seen to be composed of intermixed meningioma and metastatic prostate carcinoma. Case 3: 59 year old man with a history of widely disseminated prostate carcinoma, initially diagnosed 4 years prior. He had a left foot drop and left lower extremity weakness. Neuroimaging studies identified an extra-axial tumor with significant vasogenic edema. The resected lesion was diagnosed as prostate carcinoma, metastatic to meningioma. The terms "tumor-to-tumor metastasis" and "collision tumor" are discussed. Radiological imaging techniques, such as standard CT and MR, cannot reliably identify the presence of metastasis within a meningioma. However physiology-based neuroimaging methods, such as perfusion MR and MR spectroscopy, maybe more useful in noninvasively differentiating tumor histology.

Back to Top | Article Outline

FRIDAY POSTER SESSION 2

113 Synaptic Plasticity in Parkinson's Disease as Revealed by the Study of Trans-synaptic Cell Adhesion Molecules

Lili-Naz Hazrati. University of Toronto

Parkinson's disease (PD) is a movement disorder associated with changes in the basal ganglia (BG). Its pathophysiology involves loss of dopaminergic input to the sensorimotor territories of the striatum and ensuing neuronal discharge abnormalities within the entire motor circuit. It is widely speculated that most of the pathophysiology observed in PD patients arises from striatal dysfunction, which then translates into changes throughout basal ganglia circuits. Classically the BG-thalamocortical circuitry model has been used to explain the pathogenesis of PD by an imbalance in the direct D1-mediated and indirect D2-mediated dopaminergic pathways. However, some changes such as altered discharge patterns in the pallidal complexes are difficult to reconcile with the model. This suggests that more complex changes occur beyond the straightforward circuit physilogy of the model; changes that likely involve cellular and synaptic properties of neurons in the extra-striatal components of BG. Neurexins (NRXNs) and neuroligins (NRLG) are cell adhesion proteins that are crucial in maintaining the functional balance of excitatory and inhibitory synapses. Our results indicate that in PD, levels of NLGN are extensively decreased in both pallidal segments. This suggests that NLGNs (and possibly NRXNs) undergo important level changes in the pallidum of PD patients and possibly switches in NLGN and NRXN isoforms are a likely possibility. These results provide the first evidence of molecular changes at the synaptic level that can have a critical effect on the firing properties of pallidal neurons in PD. The reversibility of these changes as well as the causative mechanisms remain to be unraveled.

Back to Top | Article Outline
114 GRN/PGRN Gene Expression Regulation via a microRNA, Studied using in vitro and in vivo Experiments

Wang-Xia Wang, Kathryn Saatman, Sindhu Madathil, Bernard Rajeev, Peter Nelson. University of Kentucky

Granulin (GRN, or progranulin/PGRN) is a protein involved in wound repair, inflammation, and neoplasia. GRN has also been directly implicated in frontotemporal dementia and may contribute to Alzheimer's disease pathogenesis. However, genetic regulation of GRN is poorly understood. MicroRNAs (miRNAs) are powerful players in gene expression regulation that were discovered relatively recently. MiRNAs are relatively short (22 nucleotides) RNA molecules that are known to act potently at the level of mRNA translation. In a high-throughput experimental miRNA assay, we found that GRN mRNA is the strongest target for miR-107 in human H4 "neuroglioma" cancer cells. MiR-107 has been implicated in Alzheimer's disease pathogenesis. Sequence elements in the open reading frame - rather than the 'canonical' 3' untranslated region - of GRN mRNA are recognized by miR-107 and are highly conserved among vertebrate species. In vitro and in vivo studies indicate that regulation of GRN by miR-107 may be functionally important. Glucose supplementation in cultured cells that leads to increased miR-107 levels also produce decreased GRN expression including changes in cell compartmentation and decreased secretion of GRN protein. This effect was eliminated following miR-107 transfection. We also tested an in vivo mouse model where miR-107 has been shown to be downregulated. In brain tissue subjacent to 1.0 mm depth controlled cortical impact, surviving hippocampal neurons show decreased miR-107 with augmentation of neuronal GRN expression. These findings indicate that miR-107 contributes to GRN expression regulation with implications for brain disorders including brain trauma and neurodegenerative diseases.

Back to Top | Article Outline
115 Cognitive Improvement After Ventriculoperitoneal Shunt Placement in Alzheimer Disease and non-Alzheimer Dementias

John Donahue1, Conrad Johanson2, Petra Klinge2, Edward Stopa1, Stephen Salloway3, Brian Ott4, Stephen Mernoff5, John Stoukides6, Suzanne de la Monte1, Miles Miller1, Gerald Silverberg7. 1Dept. of Pathology, Rhode Island Hospital/Alpert Medical School; 2Dept. of Neurosurgery, Rhode Island Hospital/Alpert Medical School; 3Dept. of Neurology, Butler Hospital/Alpert Medical School; 4Dept. of Neurology, Rhode Island Hospital/Alpert Medical School; 5Dept. of Neurology, Providence VA Medical Center/Alpert Medical School; 6Dept. of Internal Medicine, Roger Williams Med Ctr/B.U. Sch of Med; 7Dept. of Neurosurgery, Stanford University Medical Center

Introduction: Growing evidence suggests that aging-induced 'wear and tear' on the blood-brain and blood-CSF barriers contribute to the development of dementia. Our novel hypothesis posits a continuum whereby aging-related disturbed barrier functions progressively lead to the accumulation of potentially toxic peptides and proteins and to the development of ventriculomegaly and normal-pressure hydrocephalus (NPH). This NPH syndrome ultimately contributes to clinical dementia in Alzheimer disease (AD) and possibly other forms of neurodegeneration.There are numerous case reports of significant cognitive improvement after shunt placement in clinically diagnosed NPH patients. Beneficial effects in patients with AD have also been reported, but the therapeutic efficacy of shunt placement for treating AD remains controversial. There are no studies indicating the beneficial effects of shunt placement in patients with non-AD dementias, such as frontotemporal dementia (FTD), progressive supranuclear palsy (PSP), and dementia with Lewy bodies (DLB).

Methods: We report a series of four dementia cases that all exhibited a sustained improvement in cognitive abilities (months to years) following VP shunt placement.

Results: At autopsy, the first patient was found to have evidence of severe AD (Braak/Braak stage VI/VI). Our second patient had classical FTD. The third patient had evidence of DLB with superimposed early PSP. The fourth patient had classic PSP. All four patients had evidence of ventriculomegaly and white matter injury.

Conclusions: Although preliminary, our data suggest that VP shunt placement may be an under-utilized treatment modality that should be considered in the proteinopathy-based dementias; e.g., AD, DLB, and the tauopathies that exhibit the ventriculomegaly and white matter injury typically associated with NPH.

Back to Top | Article Outline
116 Clinicopathologic Characterization of Frontotemporal Dementia Associated with the IVS10-10G>T MAPT Gene Mutation

Bernardino Ghetti1, Jill Murrell1, Matthew Hagen1, David Geldmacher2, Tatiana Foroud1, Michel Goedert3, Salvatore Spina1. 1Indiana University; 2University of Virginia; 3Medical Research Council

Background: Mutations in the Microtubule Associated Protein Tau (MAPT) gene are associated with frontotemporal lobar degeneration with tau-immunoreactive deposits (FTLD-tau). We report clinical and neuropathologic findings of two siblings affected with FTLD-tau associated with the IVS10-10G>T MAPT gene mutation.

Subjects: At age 41, the proband developed headaches, forgetfulness, progressive non-fluent aphasia and disinhibition. One year later, she developed executive dysfunction, sleep disorder, and loss of judgment and insight. Later, she lost initiative, became mute, and developed urinary incontinence and frontal release signs. She died at age 48. At age 55, the proband's brother presented short-term memory loss, behavioral changes, loss of judgment and insight, spatial disorientation and urinary incontinence. He developed language difficulties and died at age 60. Subjects' father and paternal grandmother presented progressive non-fluent aphasia at age 40 and died in their mid-40s.

Methods: Postmortem examination of the brain was carried out on the proband and her brother. DNA was extracted from fresh blood samples.

Results: Macroscopically, there was severe frontal and temporal atrophy as well as marked atrophy of the striatum and hippocampus. There was severe neuronal loss, gliosis and microvacuolar changes of the frontal and temporal cortices. Tau-immunoreactivity was see in neurons and tufted astrocytes in the frontal and temporal cortices, striatum, amygdala, thalamus, entorhinal cortex and brainstem. Tau-immunoreactivity was seen in oligodendroglial cells in the form of coiled bodies, which were numerous in the subcortical white matter. The IVS10-10G>T MAPT gene mutation was found in one allele of both subjects'. The MAPT haplotype was H1H2 and H1H1 in the proband and proband's brother, respectively.

Summary: We describe the neuropathologic findings in subjects affected with FTLD-tau associated with the IVS10-10G>T MAPT gene mutation in the background of an H1 MAPT allele. Supported by P30AG010133 and U24AG021886.

Back to Top | Article Outline
117 Bridge Cases Between the Classical Variants of FUSopathies

David Munoz1, Lorne Zinman2, Ekaterina Rogaeva3, Beverly Young2, Ian Mackenzie4, Juan Bilbao2. 1St. Michael's Hospital, University of Toronto; 2Sunnybrook Hospital; 3University of Toronto; 4University of British Columbia

Mutations in the FUS gene cause familial amyotrophic lateral sclerosis (ALS) type 6. The FUS protein has been identified as the critical component of neuronal cytoplasmic inclusions (NCI) in TDP-43 negative ALS, and in 3 previously considered unrelated variants of frontotemporal lobar degeneration (FTLD): atypical FTLD with ubiquitin inclusion (aFTLD-U), basophilic inclusion body disease (BIBD) and FTLD-IF, formerly known as neuronal intermediate filament inclusion disease. We encountered 2 patients simultaneously exhibiting histopathological features of several variants. Both patients were male, ages 59-62 and 70-72 at presentation-death. Patient 1 presented with slurred speech and choking, followed by parkinsonism and behavioral variant frontotemporal dementia, and finally diffuse bilateral weakness. At autopsy FUS antibodies revealed numerous NCI and vermiform neuronal intranuclear inclusions (NII). Subcortical BIBD-type inclusions were also FUS+. There were synuclein + Lewy bodies in the substantia nigra, but no internexin+ NCI were seen. Patient 2, presented with classical bulbar and spinal ALS. Neurons contained 2 types of NCI: basophilic (FUS+) and pale (neurofilament and internexin +). FUS + NCI appeared round and grainy whereas NF + NCI were ropey. NII were absent. FUS+ glial cytoplasmic inclusions were abundant in both cases. Genetic analysis showed no mutation in the FUS, TDP, or progranulin genes in either case. Vermiform NII characterize aFTLD-U, and thus patient 1 bridges BIBD and aFTLD-U. NCI characteristic of BIBD and FTLD-IF are simultaneously present in patient 2. We conclude that aFTLD-U, BIBD, and FTLD-IF represent a spectrum of manifestations of a basic FUSopathy, rather than discrete entities.

Back to Top | Article Outline
118 Neurites Containing C-Terminally Truncated A-Synuclein in Alzheimer's Disease Without Conventional Lewy Body Pathology

Karen Lewis1, Yang Su2, Olina Jou2, Caroline Ritchie1, Chan Foong2, Linda Hynan3, Charles White2, Philip Thomas1, Kimmo Hatanpaa4. 1Department of Physiology; 2Department of Pathology; 3Department of Clinical Sciences; 4Department of Pathology, UT Southwestern Medical Center

The pathologic hallmark of Parkinson's disease and diffuse Lewy body disease (DLBD) is the deposition of aggregated a-synuclein (a-syn) in the form of Lewy bodies and Lewy neurites. Cases with both Alzheimer's disease (AD) and cortical Lewy pathology represent the Lewy body variant of AD (LBV) and constitute 25% of AD cases. C-terminally truncated forms of a-syn enhance aggregation of a-syn in vitro. To investigate for the presence of C-terminally truncated a-syn in DLBD, AD, and LBV, we generated polyclonal antibodies to truncated a-syn ending at residues 110 (a-syn110) and 119 (a-syn119), putative products of endoproteolytic cleavage by the 20S proteasome. The specificity of the antibodies was demonstrated by immunoblots of recombinant truncated a-syn. Double-immunofluorescence on the cingulate cortex showed that a-syn110 and a-syn140 (full-length) aggregates were predominantly not colocalized in LBV. Aggregates containing a-syn140 also contained a-syn119, but some aggregates contained only a-syn119. Immunohistochemistry and image analysis on tissue microarrays of cingulate cortex from cases of DLBD (n = 27), LBV (n = 27), AD (n = 19), and age-matched controls (n = 15) showed that AD is characterized by frequent Lewy neurites containing a-syn119. Notably, these neurites did not contain any a-syn110 or a-syn ending at residues 122-140. The presence of a-syn119 aggregates in AD without conventional Lewy body pathology suggests that AD and Lewy body disease may be even more closely related than previously thought. (Supported by NIH DK49835, Welch Foundation, GM07062, NIA/NIH 5P30AG012300, NCRR/NIH UL1RR024982, Winspear Family Center for Research on the Neuropathology of Alzheimer Disease, and McCune Foundation).

Back to Top | Article Outline
119 The Spectrum of FUS-Positive Pathology in Frontotemporal Lobar Degenerations

Tamas Revesz1, Tammaryn Lashley2, Zashen Ahmed2, Jonathan Rohrer2, Jason Warren2, Safa Al-Saraj3, Nick Fox2, Hans Braendgaard4, Martin Rossor2, Andrew Lees2, Janice Holton2. 1Institute of Neurology, University College London; 2UCL Institute of Neurology, University College London, London, UK; 3Institute of Psychiatry, King's College London, London, UK; 4Aarhus Kommunehospital, Aarhus, Denmark

Atypical frontotemporal lobar degeneration (aFTLD-U) and neuronal inpresencetermediate filament inclusion disease (NIFID) are characterised by the ubiquitin-positive, TDP-43 and tau-negative inclusions. Mutations in the fused in sarcoma (FUS) gene have been shown to cause familial amyotrophic lateral sclerosis (ALS) associated with FUS-positive inclusions. Subsequent studies demonstrated that inclusions in aFTLD-U, NIFID and basophilic inclusion body disease (BIBD) contain FUS protein. FUS pathology was systematically investigated in 6 NIFID (3 with spinal cord) and 7 aFTLD-U cases (2 with spinal cord) with antibodies to FUS, alpha-internexin, ubiquitin and p62. FUS-positive neuronal cytoplasmic (NCI) and intranuclear inclusions (NII) and their distribution in cerebral cortex, subcortical and brainstem nuclei and spinal cord were recorded. When available, clinical, neuroimaging and neuropsychometry data were analysed. The most common presenting clinical syndrome was behavioural variant frontotemporal dementia (bvFTD). Neuroimaging revealed mainly atrophy of the frontal and anterior temporal lobes, but also atrophy of the caudate. In some NIFID cases clinical evidence of motor neuron involvement was present. Several FUS-positive inclusion types were common to both diseases. The NCIs were frequently globular or 'bean' shaped while the NIIs were either filamentous or vermiform and varied in number. Cortical FUS-positive NCIs were often Pick body-like in NIFID; ring-like or comma-shaped inclusions were seen in both conditions. Brainstem and spinal cord motor neurons contained variable numbers of compact, granular or skein-like NCIs. alpha-Internexin immunoreactivity was restricted to NIFID, but identified only a minority of all FUS-positive inclusions. In our NIFID and aFTLD cases the clinical features were heterogeneous, although the most common association was with bvFTD. Clinical and pathological evidence of ALS may be found in cases previously diagnosed as NIFID. FUS-positive inclusions in both cerebral cortex and motor neurons in NIFID and aFTLD-U extend the spectrum of diseases with frontotemporal degeneration and involvement of the motor system.

Back to Top | Article Outline
120 TDP-43 Proteinopathy in Chronic Traumatic Encephalopathy

Ann McKee1, Brandon Gavett2, Robert Stern2, Christopher Nowinski2, Robert Cantu2, Chris Sullivan3, Daniel Perl4, E. Tessa Hedley-Whyte5, Daniel Daneshvar2, Neil Kowall6, Andrew Budson3. 1Bedford VAMC/Boston University School of Medicine; 2Boston University School of Medicine; 3Bedford VAMC GRECC; 4Mount Sinai School of Medicine; 5Massachusetts General Hospital, Harvard Medical School; 6Jamaica Plain VAMC GRECC

Mild repetitive head injury is associated with the development of chronic traumatic encephalopathy (CTE), a progressive tau immunoreactive neurofibrillary degeneration of the brain. The characteristic features of CTE are extensive tau-immunoreactive neurofibrillary tangles deposited throughout the frontal and temporal cortices in a patchy, superficial distribution, most prominent around small blood vessels and at sulcal depths in the relative absence of beta-amyloid deposits (McKee et al., 2009). Using standard techniques and a rabbit polyclonal to TDP-43, we examined 10 cases of CTE and found a widespread TDP-43 proteinopathy in addition to tau neurofibrillary tangles. In 9 cases, there were abundant TDP-43 neurites, neuronal intracytoplasmic inclusions (NCI), diffusely immunoreactive neurons and glial cytoplasmic inclusions (GCI) in the frontal and temporal cortices, medial temporal lobe, basal ganglia, diencephalon, and brainstem. TDP-43+ NCI were found in the substantia nigra and oculomotor nuclei and TDP-43+ GCI and neurites were found in the white matter. In 1 case, TDP-43 positive neurites were limited to the brainstem. Confocal microscopy showed only minimal co-localization of TDP-43 and tau. While TDP-43 proteinopathy has been described in other 3R/4R tauopathies, including Alzheimer's disease and Parkinson's Dementia Complex of Guam, in those conditions it is primarily found in the medial temporal lobe co-localized with tau. Although CTE is also a 3R/4R tauopathy, TDP-43+ NCI, diffuse neurons, and GCI were widely distributed throughout the brain. These findings include areas not previously known to be involved, such as the substantia nigra pars compacta and oculomotor nuclei. The pattern of TDP-43 immunoreactivity in CTE is most similar to that found in FTLD-U (TDP) (MacKenzie type 3), yet there are distinctive differences. Axonal damage may be the fundamental underlying mechanism of TDP-43 proteinopathy in both conditions.

Back to Top | Article Outline
121 Distribution of Phosphorylated Alpha-Synuclein Histopathology in the Bodily Organs of Subjects With Lewy Body Disorders

Thomas Beach1, Charles Adler2, Lucia Sue1, Charles White3, Haru Akiyama4, John Caviness2, Holly Shill1, Marwan Sabbagh1, LihFen Lue1, Douglas Walker1. 1Sun Health Research Institute; 2Mayo Clinic Arizona; 3University of Texas Southwestern Medical Center, Dallas, TX; 4Tokyo Institute of Psychiatry, Tokyo, Japan

A sensitive immunohistochemical method for phosphorylated alpha-synuclein was used to stain sets of sections of spinal cord and tissue from 41 different sites in the bodies of 92 subjects, including 23 normal elderly, 7 with incidental Lewy body disease (ILBD), 17 with Parkinson's disease (PD), 9 with dementia with Lewy bodies (DLB), 19 with Alzheimer's disease with Lewy bodies (ADLB) and 17 with Alzheimer's disease with no Lewy bodies (ADNLB). The relative densities and frequencies of occurrence of phosphorylated alpha-synuclein histopathology (PASH) were tabulated and correlated with diagnostic category. The greatest PASH frequency occurred in the spinal cord and paraspinal sympathetic ganglia, followed by the vagus nerve, the gastrointestinal tract and endocrine organs. The frequency of PASH within other organs and tissue types was much lower. Spinal cord and peripheral PASH was most common in subjects with PD and DLB, where it appears likely that it is universally widespread. Subjects with ILBD had lesser densities of PASH within all regions but had frequent involvement of the spinal cord and paraspinal sympathetic ganglia, with less-frequent involvement of end-organs. Subjects with ADLB had infrequent involvement of the spinal cord and paraspinal sympathetic ganglia with rare involvement of end-organs. Within the gastrointestinal tract there was a rostrocaudal gradient of decreasing PASH frequency and density, with the lower esophagus and submandibular gland having the greatest involvement and the colon and rectum the lowest. The implications of these findings for non-motor symptoms of PD and other Lewy body disorders is discussed.

Back to Top | Article Outline
122 Incidence and Extent of Alpha-Synucleinopathy in the Human Aging Peripheral and Central Nervous System

Sayaka Funabe1, Hiroyuki Hatsuta1, Tadashi Adachi1, Mikiko Sugiyama1, Yuko Saito2, Tomio Arai1, Motoji Sawabe1, Nobutaka Hattori3, Shigeo Murayama1. 1Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology; 2National Center Hospital for Neurology and Psychiatry; 3Department of Neurology, Juntendo University

Background: Prion hypothesis of Lewy body disease speculates the initial entry zone of the specific pathogen as gastrointestinal and olfactory tracts.

Methods: Consecutive autopsy cases since October 2008 from a general geriatric hospital were employed for this study. Brain and spinal cords, as well as olfactory epithelium, cribriform plate, thoracic sympathetic ganglia, anterior wall of the left ventricle of the heart, the wall of gastroesophageal junction, bilateral adrenal glands and skins of abdominal wall and upper and lower extremities were immunohistochemically examined with anti- phosphorylated alpha-synuclein antibody (psyn#64). The central nervous system (CNS) was also screened with anti- phosphorylated tau (AT8), Abeta (11-28), ubiquitin and TDP43 antibodies.

Results: Until now, sixty seven cases were examined. Ten cases of Alzheimer disease and six cases of Parkinson disease/ dementia with Lewy bodies were included in the series. Twenty eight patients presented alpha-synucleinopathy (AS) in the olfactory bulb, six of whom also presented AS in olfactory mucosa and one in a nerve fascicle in cribriform plate. Fourteen cases contained AS in dorsal motor nucleus of vagus, 11 of whom had AS in enteric nerve plexus. AS was also observed in seventeen cases of the sympathetic ganglia, 11 cases of the heart, five cases of the adrenal gland, no case of the skin, 13 cases of the spinal cord and 20 cases of the amygdala.

Conclusion: Our study demonstrated higher incidence of AS in olfactory bulb than in olfactory mucosa and in dorsal motor nuclus of vagus than in enteric plexus. The incidence of AS in the peripheral nervous system (PNS) was lower than the AS in the CNS and occur in more advanced stage of AS in the CNS. Our study did not support the hypothesis that AS extended from the PNS to the CNS in human aging process.

Back to Top | Article Outline
123 Isolation of Spiroplasma from the Eyes of Sheep Infected With Scrapie Reveals a New Direction for TSE Research

Frank Bastian1, Charles Boudreaux1, Sue Hagius1, Marie Bulgin2, Sharon Sorensen-Melson2, Frederick Enright3, Philip Elzer3. 1LSU AgCenter, Dept of Veterinary Science; 2Veterinary Science Dept, University of Idaho College of Agriculture; 3Department of Veterinary Science, LSU Agricultural Center

Spiroplasma have been linked to scrapie in sheep, chronic wasting disease (CWD) in deer and Creutzfeldt-Jakob disease in humans by ultrastructural and molecular studies. These cell wall-less bacteria have been cultured from brains of transmissible spongiform encephalopathy (TSE)-confirmed cases via passage in embryonated eggs. Inoculation of the lab strain [suckling mouse cataract agent (SMCA)] of Spiroplasma mirum or Spiroplasma sp. isolated from TSE (scrapie or CWD) confirmed brains into rodents and small ruminants induces spongiform encephalopathy and neurological degeneration simulating naturally occurring disease. In this study, examination of the eyes of deer and sheep experimentally inoculated with SMCA revealed severe retinopathy identical to eye changes characteristically seen in scrapie sheep. Immunohistochemistry of the SMCA-infected sheep eyes using hyperimmune rabbit serum specific for SMCA showed spiroplasma antigen concentrated in the retina, vitreous and corneal endothelia. Based on these results, we focused on eyes obtained from a scrapie research flock at the University of Idaho to determine if spiroplasma were present. The contents of the sheep eye were directly inoculated into M1D media and after two weeks incubation at 37oC, the spiroplasma were found by dark-field microscopy (DFM) in samples from 3 of 4 scrapie sheep. The eye tissues were also explanted onto tissue cell cultures and following incubation, spiroplasma were seen in one instance in the tissue culture fluid by DFM and in a tissue culture pellet by electron microscopy. A control eye from a normal sheep handled in the same manner was negative for spiroplasma. These data suggest the ruminant eye will be the focus of future investigations for factors involved in the pathogenesis of TSE, including determining the relationship between spiroplasmosis and the prion.

Back to Top | Article Outline
124 Whipple's Disease: An Endless Infection Forty Four Years of Disease and 15 Years of Brain Involvement, Report of a Case

Ana Lia Taratuto1, Graciela Zuccaro2, Eugenia Arias3, Pieter Mac Keith4, Clara Muller5, Raul Dominguez5. 1Institute for Neurological Research.FLENI.Buenos Aires.Argentina; 2Neurosurgery, Garrahan National Pediatric Hospital, Argentina; 3Neuropathology-Institute for Neurological Research, Argentina; 4Brighton and Sussex Medical School, London,United Kingdom; 5Neurology, Sirio Libanés Hospital, Buenos Aires, Argentina

A 76 year old male had migratory polyarthralgias, abdominal pains, changes in bowel evacuation and fever with multiple relapses and remissions since the age of 33. Whipple's disease (WD) was diagnosed by duodenal biopsy in his 53rd year. At 62 yrs old he had abnormal frontal gait and normal pressure hydrocephalus (NPH) that was surgically treated. For the next 8 years, he was asymptomatic. Several episodes of transient dysarthria occurred at 70 and 71 years old; acute confusional state, severe gait disturbances and urinary incontinence at 72 years old. He received simultaneously Sulfametoxazol and Trimetroprime (SMT) treatment. Brain MRI showed hyperintensities in the left brain hemisphere and asymmetric ventricular enlargement. During a second NPH surgical treatment, a ventricular synechia and brain biopsy was obtained showing macrophages full of PAS+ microorganisms consistent with tropheryma whipplei. PCR performed in the biopsy confirmed the diagnosis. Continuous SMT and periodic Ceftriazone treatments were performed with normalization of neurological symptoms. Throughout our lengthy observation,we have demonstrated infectious manifestations of WD relapses. Central Nervous System involvement by tropheryma whipplei should be suspected even in chronic encephalopathies of unclear etiology.

Back to Top | Article Outline
125 Fatal Case of Deer Tick Virus Encephalitis

Phyllis Faust1, Heng Wang2, Michelle Dupuis2, Rene Hull2, Gregory Ebel3, Emily Gilmore4, Norma Tavakoli2. 1Columbia University; 2Wadsworth Center, New York State Department of Health; 3Department of Pathology, University of New Mexico School of Medicine; 4Department of Neurology, Columbia University

Deer tick virus (Powassan lineage II) is related to Powassan virus (Powassan lineage I), a tick-borne encephalitis virus. Powassan lineage I virus is a cause of encephalitis in Canada and the Northeastern United States and is associated with high case fatality (14%) and neurologic sequelae (>50%). Involvement of deer tick virus in human disease has been poorly documented. A 62-year-old man with a past medical history of chronic lymphocytic leukemia/small lymphocytic lymphoma presented with a meningoencephalitis syndrome and died 17 days after onset of symptoms. Analyses of tissue samples obtained during surgery and at autopsy revealed a widespread necrotizing meningoencephalitis. Nucleic acid was extracted from formalin-fixed tissue, and the presence of deer tick virus was verified on a flavivirus-specific polymerase-chain-reaction (PCR) assay, followed by sequence confirmation and phylogenetic analysis. Immunohistochemical studies with antisera specific for deer tick virus identified numerous immunoreactive neurons, with prominent involvement of large neurons in the brain stem, cerebellum, basal ganglia, thalamus, and spinal cord. This case demonstrates that deer tick virus can be a cause of fatal encephalitis. In areas of northeastern and northcentral United States, deer tick virus has been reported to infect as many as 1-5% of adult Ixodes scapularis ticks and may also be associated with polymicrobial infections in these ticks. Diagnostic testing for POW viruses are not routinely performed for patients with symptoms of encephalitis and standard serologic tests will not distinguish these two strains. Future studies are needed to better establish the human incidence of Powassan versus deer tick virus infections and the relative virulence of these strains.

Back to Top | Article Outline
126 Ribonucleic Acids Co-Localize to Prion Protein Aggregates in Sporadic and Variant CJD

Brent Harris1, Pablo Valdes1, Colin Smith2, Surachai Supattapone1. 1Dartmouth Medical School; 2Western General Hospital

There is incomplete understanding of the mechanism of conversion of PrPc to PrPsc with subsequent PrP aggregate deposition in prion pathogenesis. We previously showed that RNA co-localized to PrP aggregates in situ in scrapie infected hamster brains, suggesting that RNA, or other such polyanionic molecules, may become incorporated into stable PrPsc complexes in the formation of hamster prion aggregates in vivo. In this study we address the hypothesis that RNA also localized to PrP aggregates in human prion diseases. To test this hypothesis, we utilize a double-labeling assay using the cationic dye acridine orange to stain for RNA and PrP immunohistochemistry to detect the PrP aggregates. Double-labeling and differential enzymatic treatments with RNase and/or heparinase of tissue sections from sporadic and variant forms of Creutzfeldt-Jakob disease are performed. We find that RNA co-localizes to neuropathological lesions of PrP aggregates in both sporadic and variant Creutzfeldt-Jakob disease infected brain tissues. Quantitatively, there is less co-localization of RNA to human PrPsc than hamster PrPSsc, although a careful analysis suggests a statistically significant association. Additional studies are required to determine whether RNA plays a role in the formation of human prions.

Back to Top | Article Outline
127 Cerebral β-Amyloid Deposition in HIV Infection

Virawudh Soontornniyomkij, Schafer Boeder, David Moore, Ben Gouaux, Cristian Achim. University of California, San Diego

Differential individual susceptibility to the development of HIV-associated neurocognitive disorders (HAND) may be attributed to differences in complex interactions among HIV, host and comorbid factors that may contribute to neural injury. The premature appearance of cerebral β-amyloid (Aβ) and tau pathologies in HIV+ brains was shown to increase with age. We explored the relationship between these histopathologic lesions and clinical parameters including age, HAND, methamphetamine use and hepatitis C virus (HCV) serostatus in postmortem brains from the California NeuroAIDS Tissue Network. Of 30 patients, 8 were = 50 years old, 6 with normal cognition, 16 with HAND, 14 with methamphetamine use, and 7 with HCV seropositivity. Immunoperoxidase staining was performed on paraffin-embedded frontal cortex tissues for Aβ40, Aβ42 and p-tau. Of 30 brains, a concurrence of Aβ40 and Aβ42 plaques was observed in 7, and Aβ40 plaques only were present in 3. There were trends for Aβ42 plaques to occur more frequently in older (=50 years) patients (P = 0.06, 2-tailed Fisher's exact test), for Aβ40 and Aβ42 plaques to happen more often in patients without methamphetamine use (P = 0.058 and 0.086, respectively), and for Aβ40 plaques to occur preferentially in patients without HCV seropositivity (P = 0.064). No significant association was found between the presence of Aβ40 or Aβ42 plaques and the diagnosis of normal cognition vs. HAND. These findings suggest that methamphetamine and HCV may promote cerebral Aβ clearance possibly via enhancement of microglial activation. The presence of Aβ40 plaques without accompanying Aβ42 plaques in HIV+ brains is in contrast to the characteristic findings in Alzheimer's disease brains, suggesting different mechanisms of Aβ deposition.

Back to Top | Article Outline
128 An Autopsy Study of Putative Lyme Disease With Neurological Manifestations

Boro Ilievski1, Ziyan Liang2, Branislav Mancevski3, Brian Fallon4, Andrew Dwork4. 1NY State Psychiatric Inst/School of Medicine, SKopje, Macedonia; 2Columbia University/Chinese PLA General Hospital; 3NY State Psych Inst/Columbia University; 4NY State Psychiatric Inst/Columbia University

Neurological symptoms are frequently attributed to Lyme disease in seropositive patients. Response to antibiotics provides supportive evidence. However, the roles of spirochetes and immune processes remain unclear. Furthermore, there is often evidence of independent neurological disease, so it is unclear whether Lyme infection is causative, exacerbatory, or incidental. Autopsy studies may shed light on this. We present four cases of seropositive individuals with sensory or cognitive symptoms. All were treated with antibiotics, and three showed at least temporary improvement. Three died of their disease, and one committed suicide. Neuropathological examinations of one case showed multiple foci of necrosis and cellular reaction in the brain. A second case, with clinical and pathological features of Cogan's syndrome, also showed evidence of chronic cerebral vasculitis. Neuropathological examinations of the remaining cases are in progress, as are stains for Borrelia and other spirochetes, as well as characterization of the inflammatory elements. Financial support provided by the Lyme and Tic-Borne Disease Research Center at Columbia University, established by Time for Lyme, Inc. and the Lyme Disease Association, Inc.

Back to Top | Article Outline
129 Clostridium Septicum Pneumocephalus and Hemolytic Uremic Syndrome: A Case Report and Review of the Literature

Sarah Martin1, Stephen Allen2, Philip Faught2, Dean Hawley2, Jose Bonnin1, Eyas Hattab2. 1Indiana University School of Medicine, Department of Pathology; 2Indiana University School of Medicine, Dept. of Path. and Lab. Med.

Clostridium septicum infection following hemolytic uremic syndrome is rare and carries a poor prognosis, especially when the brain is involved. We report a case of a previously healthy 2-year-old male who presented with one to two days of anuria and bloody diarrhea. He was admitted to the local children's hospital with a diagnosis of hemolytic uremic syndrome, presumably secondary to E. coli O157. Eleven hours after admission, he required intubation and was noted to have fixed and dilated pupils. Head CT revealed left frontal subcortical white matter vasogenic edema and gyral hyperdensity, as well as scattered pockets of pneumocephalus. Left-to-right midline shift and left uncal herniation were also observed. Neurosurgical consultation advised that no intervention was possible. The patient expired 14 hours after admission. Ante-mortem blood cultures grew Clostridium septicum. Gross pathologic examination of the brain revealed a 6.5 cm area of dark brown discoloration with friable tissue and cavitation in the left frontal and parietal lobes, extending down the internal capsule to the midbrain, consistent with a large intraparenchymal cerebral hemorrhage. There was extensive vacuolization throughout the brain, cerebellum, and brainstem. Microscopic examination revealed vacuolization and diffuse colonization with rod-shaped bacteria, but without the expected tissue response. General autopsy revealed a similar diffuse bacterial colonization of nearly every organ. There have been only six previously reported cases of C. septicum infection following hemolytic uremic syndrome, four of which had brain involvement. Injured ischemic colonic epithelium is the likely portal of entry of C. septicum in these children, and the mechanism of spread to distant sites appears to be hematogenous. Mortality rate is high, with only two known survivors. With brain involvement, the mortality rate is even higher at 75 percent, with the one known survivor having a brain abscess rather than diffuse pneumocephalus.

Back to Top | Article Outline
130 Neuropathologic Findings in a Fatal Case of H1N1 Influenza Virus Infection

Wael Milyani, Kathryn Skitarelic, Fahad Bafakih, Kymberly Gyure. West Virginia University

Human infection with the novel H1N1 influenza virus was first reported in April 2009 and has reached pandemic proportions in a short period of time. This virus has caused a considerable number of deaths, particularly in young patients. We present the neuropathologic findings of a 17-year-old woman who succumbed to H1N1 influenza virus infection. The patient presented following a 4-day history of an upper respiratory infection and was admitted with a diagnosis of pneumonia. Her past medical history was significant for morbid obesity and obstructive sleep apnea. She was given broad-spectrum antibiotics, but her respiratory status continued to decline and she required intubation and mechanical ventilation. She was sedated and paralyzed to maximize oxygenation. One week into the course of her illness, her pupils were noted to be fixed and dilated, and a CT scan showed cerebral edema with descending herniation of midline structures. Support measures were subsequently withdrawn. A pre-mortem sample of respiratory secretions and a post-mortem tracheal swab sample were positive for influenza A by polymerase chain reaction testing. Significant autopsy findings included diffuse alveolar damage with intra-alveolar hemorrhage and macrovesicular hepatic steatosis with bridging fibrosis. The brain weight was 1480 g with diffuse widening of the gyri and narrowing of the sulci but was without significant herniation. Essentially all gray matter structures exhibited dusky discoloration, and numerous petechial hemorrhages were present at the base of the forebrain, in the temporal lobes, and at multiple brainstem levels. Microscopic examination confirmed the presence of petechial hemorrhages and diffuse anoxic encephalopathy. There was no evidence of a meningoencephalitis. The neuropathologic findings in this case are most likely secondary to the patient's severe systemic disease rather than a primary manifestation of her viral infection, however, an awareness of potential neurologic complications in this patient population is important to ensure adequate treatment.

Back to Top | Article Outline
131 Cerebellar Ganglioglioma, an Uncommon Location for a Rare Tumor: A Report of Three Cases

Peter Saunders, Luis Moral, Dennis Oh. Baystate Medical Center

The cerebellum is an uncommon location for the ganglioglioma, a rare tumor characterized by the presence of neoplastic neurons and glial cells, which is usually found supratentorially. There are 30 case reports of cerebellar ganglioglioma in the literature and the largest series to date includes two cases. The majority of cases have occurred in patients under the age of 30. We report three cases of cerebellar ganglioglioma in adult patients, all diagnosed and treated at our institution between 2001 and 2009. Our patients were 25, 49, and 53 years of age and presented with headaches, posterior headaches, and vertigo respectively. Upon imaging with MRI the first patient was found to have a large posterior fossa mass, the second patient a 1.8 cm left cerebellar vermian-based mass, and the third patient a 2.3 cm left cerebellar mass. Subsequently, the patients underwent craniotomy and resection of the tumors. Intraoperatively the tumors were respectively found to be multicystic, cystic with a central grayish-green avascular mural nodule, and cream-pink and fleshy with calcifications. At grossing the tumor fragments were described as red and soft in consistency. The frozen section diagnoses for the three tumors were as follows: "spindle cell neoplasm with prominent Rosenthal fibers consistent with pilocytic astrocytoma"; "favor low-grade astrocytoma"; and "hypercellular astroglial tissue in keeping with low-grade astrocytoma". On permanent section all three were found to be composed of neoplastic neurons and glial cells, and were diagnosed as ganglioglioma, WHO grade I. Cases of gangliogliomas found in the cerebellum are extremely rare, and they are difficult to differentiate from more common cerebellar tumors at frozen section. Although the majority of cerebellar gangliogliomas occur in patients younger than 30 years of age, gangliogliomas should be included in the differential diagnosis of cerebellar tumors in patients older than 30.

Back to Top | Article Outline
132 Leptomeningeal Amyloidosis in an Argentinian Patient of Basque Descent

Ana Lia Taratuto1, Horacio Breyter2, Rosana Salvatico3, Ahmet Dogan4, Christopher Klein5, P James Dyck5. 1Institute for Neurological Research. FLENI. Buenos Aires, Argentina; 2Neurology Department, Swiss Medical Institution, Buenos Aires, Argentina; 3Imaging Department, Swiss Medical Institution, Buenos Aires, Argentina; 4Laboratory Medicine and Pathology, Mayo Clinic, Rochester, USA; 5Department of Neurology, Mayo Clinic, Rochester, USA

Leptomeningeal amyloidosis is a rather infrequent expression of systemic amyloidosis due to transthyretin (TTR) deposition. TTR amyloidosis can be age-related or caused by mutations in the TTR gene. A 52 years old female, with no family history of neurological disease, developed recurrent transient aphasia and right brachiocrural motor deficit of 15 minutes duration with full recovery. A cervical vessel ultrasound, brain vessel angiography as well as a transesophagic ultrasound proved normal. Brain and spinal cord MRI showed leptomeningeal contrast enhancement. CSF proteins were increased but there were no oligoclonal bands. PCRs for CMV,VVZ, HSV, HIV and VDRL were negative. She developed 2 yrs later acute right hypoacusia. Brain stem auditive evoked potentials showed delay in central conduction while visual evoked potentials were normal. A right parietal brain and leptomeningeal biopsy showed leptomeningeal amyloidosis with subpial amyloid deposition and vessel wall involvement. Mass spectrometry based amyloid typing showed that amyloid deposits were caused by TTR deposition. Search for the most common Val 30 Met mutation of the TTR gene which causes familial amyloid polyneuropathy proved negative; while whole TTR gene sequencing is in progress. Her symptomatology progressed for the last three years,she developed dysphagia with several episodes of aspiration pneumonia (a gastrostomy was performed), bilateral deafness, muscular atrophy and difficulty in gait. Leptomeningeal amyloidosis should be considered in the differential diagnosis of meningeal involvement of unclear etiology.

Back to Top | Article Outline
133 The Spectrum of Spinal and Paraspinal Pathological Processes Encountered in Neuropathology Practice

Mahtab Tehrani1, Theodore Friedman1, Glenn Pait2, Murat Gokden1. 1Department of Pathology, University of Arkansas for Medical Sciences; 2Department of Neurosurgery, University of Arkansas for Medical Science

Many surgical procedures on the spine are performed by neurosurgeons, allowing neuropathologists to see a variety of lesions from non-neuroglial tissues, especially of bone and soft tissue origin, as well as hematolymphoid lesions and metastatic neoplasms. Some of these lesions can also present as primary nervous system pathology due to their close association with the coverings of the spinal cord. Therefore, neuropathologists should be familiar with a wide spectrum of non-neuropathological processes. Here, we present a review of neuropathological material with respect to spinal and paraspinal pathology. Pathology archives of the University of Arkansas for Medical Sciences were searched for those specimens that originated from spinal and paraspinal tissues and that were operated by a neurosurgeon between 1997-2009. Cases were analyzed for demographic, clinical and pathological features. Slides of unusual cases or of those cases requiring clarification or confirmation were reviewed.A total of 825 cases were identified (mean age: 49.3, median: 48, range: 13-91 years; male-to-female ratio: 1.28); 620 were degenerative intervertebral disc disease. The remaining 205 cases were 69 metastatic carcinomas {most commonly of renal (15), lung (13), unknown primary (12) and breast (8) origin}, 31 soft tissue neoplasms {most common: schwannoma (17)}, 24 hematolymphoid neoplasms {most common: plasma cell neoplasms (19)}, bone neoplasms {most common: chordoma (10)}, while the remainder were a variety of reactive, inflammatory, cystic and malformative lesions. A variety of spinal and paraspinal pathological conditions can be encountered in neuropathology practice due to the involvement of different types of neural and non-neural tissues in this region. While the case variety is consistent with general trends, it may fluctuate based on the subspecialty interests in the clinical departments within the institution. Neuropathologists should be familiar with these conditions, as they can also be encountered during intraoperative consultations, where the opportunity for consultation may not be readily available.

Back to Top | Article Outline
134 One Hundred Years of Neuropathology in Canada (1874-1974)

Marc Del Bigio. Pathology - University of Manitoba

After training with Virchow, in Montreal from 1874-1894 William Osler became the first Canadian to write about autopsy neuropathology. Ernest Jones, who studied under Alzheimer and Horsley, was a neuropathologist in Toronto from 1908-13, before turning to psychotherapy. William Boyd worked in Winnipeg from 1915-1937, publishing the world's first CSF cytology book in 1920. The neurosurgeons Wilder Penfield and William Cone moved to Montreal in 1928 and founded the Montreal Neurological Institute (MNI) in 1934. Penfield, who trained with Osler, Sherrington, Cushing, Greenfield, and del Rio Hortega, edited the world's first multiauthor textbook on neuropathology. Cone ran the neuropathology in his spare time until 1959. Penfield and Cone help train several influential neuropathologists including Russell, Haymaker, Earle, and Klatzo. They attracted Jerzy Olszewski from Poland in 1948, initially as a neuroanatomist, gradually transitioning to neuropathology, leaving for Saskatoon in 1956. In 1932 in Toronto, the neurohistologists Eric Linell and Mary Tom, neither of whom had pathology training, were transferred from Anatomy to serve as neuropathologists. Gordon Mathieson trained under Linell and Tom in 1954, then in 1957 became neuropathologist at the MNI. In 1959, Francoise Robert, who trained with Richardson in Boston, became the first Francophone neuropathologist in Montreal. While at the 1959 AANP meeting in Atlantic City, Olszewski and Mathieson thought it would be a good idea to have a similar meeting in Canada. In 1960 they formed the Canadian Association of Neuropathologists (CANP). Neuropathology expanded gradually in the 1960s with trainees of the Toronto, Montreal, Boston and Stanford (under Rubinstein) programs assuming positions. In 1965 the Royal College of Physicians and Surgeons of Canada (RCPSC) recognized Neuropathology as an independent specialty and the first examination given in 1968, under the proctorship of Rubinstein. The CANP celebrates its 50th anniversary in 2010.

Back to Top | Article Outline
135 Acute Autonomic, Sensory, and Motor Neuropathy With Associated Autoimmune Myositis

Neil Anderson, Khang-Cheng Ho, Richard Komorowski, Rahul Nanchal, Julia Durrant. Medical College of Wisconsin

We report a case of acute combined sensory, motor, and autonomic neuropathy with coexisting polymyositis. The patient, a 52 year old female with a remote history of lupus, presented with bilateral lower extremity numbness and weakness. Additionally, the patient had nausea, vomiting and abdominal pain. On admission she was found to have an ileus. An ileocecal resection revealed severe degeneration of Aurbach's plexus with chronic inflammation. Cerebrospinal fluid, electromyogram, and sural nerve biopsy findings were consistent with acute inflammatory demyelinating polyneuropathy. The patient failed to respond to intravenous immunoglobin and showed only mild increase in strength in response to steroids and cytoxin. Her ileus failed to resolve and as her course progressed she developed labile blood pressure. After two and a half months, the patient became acutely hypoxic and hypotensive, eventually expiring. At autopsy it was found that she had developed dilation, necrosis and perforation of the ascending colon. Histology of the gastrointestinal tract showed a diffuse and near total loss of neurons as well as inflammation within the myenteric plexus affecting the esophagus, stomach, small bowel, and large bowel. The patient's sural nerve showed inflammation, vacuolization, and demyelination consistent with a demyelinating neuropathy. There was a near complete loss of neurons within the dorsal root ganglion diffusely, and secondary degeneration of the dorsal columns within the spinal cord. Also present was degeneration and gliosis of the interomediolateral nucleus of the thoracolumbar spinal cord, indicating involvement of the sympathetic nervous system. Histology of the patient's skeletal muscle revealed neurogenic atrophy and a superimposed auto-immune polymyositis with a severe mononuclear inflammatory cell infiltrate consisting mainly of CD8 positive T cells and an absence of plasma cells. There was no evidence of lupus erythematosus. This represents a unique case of autoimmune polymyositis found in association with acute autonomic, sensory, and motor neuropathy.

Back to Top | Article Outline
136 Pathological Findings in a Case of Familial Amyloidosis, Thr60Ala (Appalachian-Type), With Prominent Peripheral Neuropathy

Juanita Evans, Charles Specht, Zachary Simmons. Penn State-Hershey Medical Center; Department of Neurology

Familial amyloid polyneuropathy (FAP) is a heterogeneous group of clinical disorders in adults, which in most cases are due to a specific point mutation in the transthyretin (TTR) gene. The most common variant is Val30Met, with change of valine to methionine at position 30 of the transthyretin molecule. Thr60Ala is a less common variant that causes severe cardiomyopathy in older adults and predominantly affects Appalachian and Northern Irish kindreds. Our patient was a 59 year old male who was non-ambulatory due to a progressive sensorimotor polyneuropathy. Past medical history included cardiomyopathy of uncertain etiology that was successfully managed with medication and frequent diarrhea and urinary incontinence that was consistent with autonomic neuropathy. His family history was significant for cardiomyopathy and renal failure. The neuropathy was initially thought to be due to chronic inflammatory demyelinating polyneuropathy (CIDP). Upon presentation at Penn State-Hershey Medical Center, nerve conduction and EMG studies demonstrated demyelination and axonal degeneration, but lacked temporal dispersion and conduction block characteristic of CIDP. Subsequent electrodiagnostic testing was consistent with axonal sensorimotor polyneuropathy. A distal radial nerve biopsy was diagnostic for mixed axonal and demyelinating neuropathy; inflammation was absent and amyloid was not demonstrated. Muscle biopsy at the same procedure showed denervation atrophy. These findings were concordant with sensorimotor neuropathy. A proximal sciatic nerve biopsy done nine months later showed severe loss of axons, with perivascular and endoneurial deposits of Congo red- and Thioflavin T-positive amyloid. Electron microscopy demonstrated 7-10 nm diameter fibrils, consistent with amyloid. TTR analysis at an outside institution revealed the Thr60Ala variant. Thr60Ala variant FAP usually presents with severe cardiomyopathy and this case is unusual in that presentation was dominated by polyneuropathy. The diagnosis of FAP in patients without a definite family history requires a high index of clinical suspicion and multiple attempts to identify amyloid deposition.

Back to Top | Article Outline
137 Compressive Spinal Elastolytic Granuloma Secondary to Occult Plasmacytoma

Jane Cryan1, Catherine Moran2, Conor O'Keane3, Michael Farrell4. 1Neuropathology Department, Beaumont Hospital; 2Neurosurgery, Beaumont Hospital; 3Pathology Department, Mater Hospital; 4Beaumont Hospital

Case A 62 year old man presented with an eight week history of severe neck pain and recurrent falls with weakness and numbness in the upper limbs. Examination showed pyramidal weakness in all limbs with extensor plantar responses. Gait was ataxic and Romberg's sign was positive. ImagingCT cervical spine showed a lytic process replacing the body of C5. T2 weighted MRI showed an enhancing soft tissue mass which bowed both the anterior and posterior longitudinal ligament and narrowed the thecal sac. The spine was decompressed, stabilised and the soft tissue removed. PathologyMicroscopic examination showed a mixed cellular infiltrate composed of giant cells which contained refractile, non-amyloidogenic eosinophilic elastic tissue and macrophages. Rare plasma cells were also present and showed Lambda light chain restriction. Skeletal survey and serum protein electrophoresis were negative. The patient received local radiotherapy and 18 months later is disease free and neurologically intact. DiscussionAnnular elastolytic giant cell granuloma of the dermis is characterised granulomatous inflammation with giant cells, elastolysis and elastophagocytosis possibly related to actinic dermal elastic injury. The granulomatous nature of the response may in part, be governed by the hosts immunological response to altered endogenous collagen or elastic tissue. Incidental elastolysis may accompany cutaneous lymphomas. In this report we describe vertebral collapse with necrosis of elastic ligamentum flavum which was complicated by an intense and unusual granulomatous reaction which almost masked an underlying plasmacytoma.

Back to Top | Article Outline
138 Rosai-Dorfman Disease Mimicking Plasmacytoma of the Skull

Dana Altenburger, Gary Pearl. Orlando Health

Isolated intracranial Rosai-Dorfman disease is a rare tumor with approximately 20 previously reported cases. The usual presentation of intracranial Rosai-Dorfman disease mimics a meningioma. Our case is unusual in the fact that it was a destructive bony lesion that clinically resembled a plasmacytoma.We report a case of a forty-five old female who presented with a left frontal scalp nodule in August 2009. It was initially thought to be a cystic lesion but the patient developed headaches and further underwent a CT scan with a follow-up MRI in December 2009. The MRI showed a T2 hyperintense, heterogeneous enhancing destructive mass in the left frontal calvarium. This mass extended into the dura as well as the soft tissue superficial to the calvarium. A craniotomy was performed and the mass was grossly resected without complication. A diagnosis of plasmacytoma was rendered at the time of frozen section due to the large number of plasma cells on touch preparation. Histological examination of the permanent tissue revealed sheets of S-100 and CD68 positive and CD1a negative lymphophagocytic histiocytes within a background of plasma cells and lymphocytes. The plasma cells were found to be polyclonal and the lymphocytes had a CD3 positive dominant subtype. No fungi or acid fast bacilli were seen with GMS and AFB stains. The histological features and immunohistochemical findings are consistent with Rosai-Dorfman disease. Our case, however, is unique with the tumor clinically mimicking plasmacytoma. This case illustrates the necessity for awareness of this lesion so a correct intraoperative diagnosis can be made.

Back to Top | Article Outline
139 Embryonal Rhabdomyosarcoma Arising in the Pituitary Gland

Thor Stein1, Yang-seok Chae2, Namehee Won2, Jeong-hyun Lee2, E. Tessa Hedley-Whyte1. 1Massachusetts General Hospital, Harvard University, Boston; 2Anam Hospital, Korea University Seoul, Korea

Rhabdomyosarcoma is a malignant tumor of skeletal muscle that predominantly affects children. It is most common in the extracranial regions of the head and neck and only exceptionally occurs intracranially. We report a case of primary intrasellar rhabdomyosarcoma in a 34 year-old man. The patient had a two year history of decreased visual acuity and increased intraocular pressure for which he was on medical therapy. He presented with a five month history of bitemporal hemianopsia. Magnetic resonance imaging revealed an intrasellar enhancing mass with suprasellar extension pushing on the optic chiasm. The mass was partially excised, but regrew in 3 months causing the same symptoms, and he had a second resection. Histologically, the biopsies were identical. The tissues were composed of infiltrating small spindled cells and elongated striated strap cells interdigitating between large eosinophilic cells with a vaguely glandular arrangement. Immunohistochemistry revealed that the spindle cells and strap cells were positive for desmin, myogenin, and myo-D1. This combination is diagnostic of embryonal rhabdomyosarcoma. The large eosinophilic cells were positive for Cam5.2, chromogranin, synaptophysin and ACTH confirming their pituitary origin. Rare smaller cells were positive for prolactin. The dominance of enlarged ACTH positive cells suggests that the rhabdomyosarcoma may have arisen in a pituitary adenoma. Primary intrasellar rhabdomyosarcoma is extremely rare and has been reported on only two other occasions. The association with an excess of ACTH secreting pituicytes was not noted in those reports.

Back to Top | Article Outline
140 Posterior Column Degeneration in the Cervical and Thoracic Spinal Cord in Lesch-Nyhan Syndrome

Jennifer Stall1, Matthew Hagen1, Marilyn Bull2, Dean Hawley1, Eyas Hattab1. 1Indiana University School of Medicine, Dept of Pathology & Lab Med; 2Indiana University School of Medicine, Dept of Pediatrics

Lesch-Nyhan syndrome (LNS) is a rare genetic disorder that results in the dysregulation of purine metabolism due to defects in the enzyme hypoxanthine-guanine phosphoribosyl transferase. It is characterized by a broad range of neuropsychological symptoms - delayed psychomotor development, compulsive self-mutilation, spasticity, and choreathetoid movements. Of the limited number of autopsies documented, about thirty have examined the brain while examinations of the spinal cord was reported in three cases only. A wide range of nonspecific neuropathological findings were recorded, but overall, no consistent gross or histological changes have been linked to LNS. We report the autopsy findings in a 15 year-old male with LNS in whom a thorough evaluation of the brain and spinal cord was conducted. The patient displayed signs of motor delay at six months of age and was subsequently diagnosed with LNS after developing self-mutilating behaviors. The patient's symptoms progressively worsened leading to increased motor difficulties and eventual wheelchair confinement. Of note, the patient developed a macrocytic anemia with normal levels of vitamin B12 and folate. At the age of fifteen, the patient died following an episode of bronchopneumonia. Postmortem brain examination failed to reveal significant gross or microscopic changes. Unlike previous reports, the cerebellar cortex was virtually unremarkable. However, sequential sectioning of the spinal cord revealed vacuolation and pallor involving the dorsal columns bilaterally in the lower cervical and upper thoracic regions. Luxol-fast blue stained sections showed marked loss of myelin in the corresponding areas. This is the first report of dorsal column demyelination in the spinal cord of a patient with LNS. Similar spinal cord findings are seen in association with vitamin B12 deficiency, which has symptoms overlapping with those of LNS. While this phenomenon could be an isolated event, it may be worth investigating, as treatment can be easily initiated with vitamin B12 supplementation.

Back to Top | Article Outline
141 Two Cases of Paraspinal Atypical Teratoid/Rhabdoid Tumor

Dimitri Trembath1, Thomas Bouldin2, Stuart Gold2, Julie Blatt2, Krystal Bottom3, Arie Perry4. 1University of North Carolina; 2University of North Carolina School of Medicine; 3Mission Health and Hospitals; 4Washington University School of Medicine

Atypical teratoid/rhabdoid tumor (AT/RT) is a highly malignant childhood neoplasm characterized by loss of INI-1 expression. Typically, AT/RTs present in the cerebral hemispheres; here we describe two cases of AT/RT in the spinal cord.The first case was a 5 year-old female with a history of progressive lower extremity weakness and ataxia. MRI revealed an intradural/extradural mass at T8-9. Following laminectomy, microscopic examination demonstrated a poorly differentiated neoplasm consisting of cells with medium to large nuclei, frequently with prominent nucleoli. Mitoses and apoptotic debris were extensive. Immunohistochemically, the tumor cells were vimentin positive with rare cells positive for desmin and a subset positive for synaptophysin. The tumor cells were negative for GFAP, chromogranin, myogenin, actin, neurofilament, S-100, CD99, and pan-cytokeratin. The second case was a 7 month-old female who presented with increasing head tilt. MRI demonstrated a left cervicothoracic paraspinal mass with extension through the neural foramina into the spinal cord. Biopsy and microscopic examination demonstrated a poorly differentiated neoplasm consisting of small round blue cells intermixed with islands of larger cells with medium to large nuclei and prominent nucleoli. Mitoses and apoptotic debris were frequent; also present was focal necrosis. Immunohistochemically the tumor cells were diffusely vimentin and CD99 positive with focal positivity for cytokeratin, EMA, and synaptophysin. Tumor cells were negative for chromogranin, myogenin, desmin, and actin. For both cases, INI-1 immunohistochemical staining showed loss of expression in tumor cells with positive staining in intra-tumoral endothelial cells and lymphocytes. Fluorescence in-situ hybridization (FISH) showed evidence of chromosome 22q loss with no evidence of EWS gene rearrangement. Given this evidence, the final diagnosis for each case was AT/RT. While AT/RTs classically present intra-cranially, there is increasing evidence that these tumors can present within the spinal cord and INI-1 studies should be considered for poorly differentiated neoplasms in this area.

Back to Top | Article Outline
142 Clincopathologic and Immunohistochemical Characteristics of Metastatic Breast Carcinoma to the Brain: A Series of 59 Cases

Sarah Martin1, Karen Johnson2, Patricia Steeg3, Eyas Hattab2. 1Indiana University School of Medicine, Department of Pathology; 2Indiana University School of Medicine, Dept. of Path. and Lab. Med.; 3National Cancer Institute, Bethesda, MD

Metastatic breast cancer to the central nervous system (CNS) is second only to lung in frequency. Affected patients typically have advanced systemic disease by the time CNS involvement is manifested. Patients with triple negative primary breast cancer and those with Her2 amplification usually are at an increased risk for metastasis. Currently, therapeutic options are limited with surgery generally offered to those with solitary lesions, and prognosis is poor. Therefore, greater understanding of this disease and its risk factors is essential for improved clinical outcome. We identified 59 cases of metastatic breast cancer to the CNS and created two cohorts: one for which paraffin blocks from both the primary and the metastatic lesions were available (matched) and another for which only the metastasis was available (unmatched). Cases were evaluated for various demographic, clinical and pathologic parameters. Additionally, immunohistochemistry for ER, PR, Her2 and EGFR, and Her2 FISH analysis were performed. Survival data was assessed. The median age at diagnosis of the CNS metastasis was 56 years with an average latency of 32 months. The majority of solitary breast cancer metastases to the CNS were supratentorial, of the infiltrating ductal type, and either triple negative or ER/PR negative-Her2 positive. In at least two-thirds of the matched cases, the immunoprofile of the metastatic lesion was predictive of that of the primary tumor. Loss of ER or PR expression occurred in the remaining cases. Follow-up interval ranged from 3 to 567 months, with a median follow-up of 57 months. At last follow-up, 25% of patients were still alive. The median overall survival from the time of diagnosis of CNS metastasis was 14 months. In general, patients experienced poor clinical outcome, however, multivariate analysis of various clinical, pathologic and immunohistochemical characteristics is underway.

Back to Top | Article Outline
143 Differential Expression of gamma-Tubulin and Class III beta-Tubulin in Medulloblastomas and Human Medulloblastoma Cell Lines

Valentina Caracciolo1, Luca D'Agostino1, Eduarda Draberova2, Vladimira Sladkova2, Dimitri Agamanolis3, Jean-Pierre de Chadarevian4, Agustin Legido4, Antonio Giordano1, Pavel Draber2, Christos Katsetos4. 1Center for Biotechnology, Temple University, Philadelphia, PA; 2IMG, Academy of Sciences of the Czech Republic, Prague; 3Akron Children's Hospital, Akron, OH; 4Drexel UCOM and St. Christopher's Hospital for Children, Phila, PA

In previous studies we have shown overexpression and ectopic subcellular distribution of gamma-tubulin and class III beta-tubulin (betaIII-tubulin) in human glioblastomas and glioblastoma cell lines (J Neuropathol Exp Neurol 2006, 65:455-467; Neurochem Res 2007, 32:1387-1398). Here we determined the expression of gamma-tubulin in relation to betaIII-tubulin in a series of surgically excised medulloblastomas (n = 20) representative of classic, large cell/anaplastic and nodular/desmoplastic subtypes as well as in the human medulloblastoma cell lines D283 Med and DAOY. In clinical tissue samples, the immunohistochemical distribution of gamma-tubulin labeling was pervasive and inversely related to neuritogenesis. Overexpression of gamma-tubulin was widespread in poorly differentiated, proliferating tumor cells but was significantly diminished in quiescent differentiating tumor cells undergoing neuritogenesis, highlighted by betaIII-tubulin immunolabeling. By quantitative real time-PCR, gamma-tubulin transcripts for TUBG1, TUBG2 and TUBB3 genes were detected in both cell lines but expression was less prominent as compared to human glioblastoma cell lines. Immunoblotting revealed comparable amounts of gamma-tubulin and betaIII-tubulin in different phases of cell cycle, however a larger amount of gamma-tubulin was detected in D283 Med as compared to DAOY cells. Interphase D283 Med cells exhibited predominantly diffuse cytoplasmic gamma-tubulin localization, in addition to the expected centrosome-associated distribution. Robust betaIII-tubulin immunoreactivity was detected in mitotic spindles of DAOY cells. Our data indicate that overexpression of gamma-tubulin may be linked to phenotypic dedifferentiation (anaplasia) and tumor progression in medulloblastomas and may potentially serve as a promising tumor marker.

Back to Top | Article Outline
144 Plasmablastic Lymphoma and Cryptococcal Meningitis in a Patient With Chronic Steroid Therapy for Sarcoidosis.

Matthew Hagen1, Kathryn Rizzo1, Thomas Witt2, Riley Snook3, Jose Bonnin4. 1Department of Pathology, Indiana University School of Medicine; 2Department of Neurosurgery, Indiana University School of Medicine; 3Department of Neurology, Indiana University School of Medicine; 4Indiana University School of Medicine

Plasmablastic lymphoma (PBL) is an aggressive form B-cell neoplasm often associated with HIV infection that typically arises in the oral cavity, gastrointestinal tract, and lymph nodes. We report a case of a primary PBL in an HIV(-) 67-year-old male with a history of chronic steroid therapy for sarcoidosis. The patient presented with altered mental status and progressive neurological deficits including third nerve palsy and ataxia. An abscess-like lesion was demonstrated radiologically in the midbrain. The diagnosis of cryptococcal meningitis was made and he was treated with IV AmBisomeR and flucytosine. There was improvement in his ataxia, but his oculomotor symptoms remained unchanged. Over the next month, the midbrain lesion continued to enlarge and neuroimaging studies showed peripheral contrast enhancement. There were also scattered small enhancing lesions in the cerebral hemispheres. The midbrain lesion did not show abnormal uptake of radiotracer by FDG-PET imaging. A stereotactic biopsy of the lesion was performed and demonstrated extensively necrotic tissue with diffuse and perivascular infiltration with highly atypical cells with plasmacytoid features. Immunohistochemically, the atypical cells were positive for CD138, MUM1 and bcl-6 while they were negative for CD20, CD79a, and PAX-5. They were also positive for Epstein-Barr virus but negative for HHV-8. In addition, the biopsy showed numerous yeast-like forms that stained positively with GMS, PAS and mucicarmin, compatible with Cryptococcus sp. Primary PBL of the CNS is extremely rare while metastases to the brain appear to occur more often than previously suspected. It usually occurs in HIV(+) patients and also in cases with a simultaneous or previous second malignancies as well as in patients with severe immunosupression, as in this case.

Back to Top | Article Outline
145 Intraventricular Dysembryoplastic Neuroepithelial Tumor in a Child: Is it the Most Common Extracortical Location of DNT?

Jane Yuan1, Haroon Choudhri2, Suash Sharma3. 1Dept of Pathology, Medical College of Georgia; 2Dept of Neurosurgery, Medical College of Georgia; 3Medical College of Georgia

Dysembryoplastic neuroepithelial tumor (DNT) is commonly located in the supratentorial cortex. Extracortical localization of DNT is extremely rare. A 15-year-old female presented with loss of consciousness after head trauma. CT scan and MRI imaging demonstrated hydrocephalus secondary to a small mass lesion in the foramen of Monro. Tumor was gross totally resected. Histologic examination showed partly microcystic architecture with oligodendroglia-like cells, glioneuronal element, and floating neurons, consistent with DNT. Although synaptophysin reactivity was noted in the axons and neuropil only, the tumor cellularity and morphology did not support a central neurocytoma. Patient was asymptomatic and was radiologically stable 3 months post-surgery. Literature review of previously reported supratentorial extracortical DNT cases demonstrate that 23 of 24 cases involved the ventricular system (as in our case) of which 8 additionally involved peri-ventricular deep gray or white matter. None of the cases recurred following surgery. This report emphasizes the need to recognize intra-ventricular DNT as the second most common location and most common extra-cortical location for histologically classic DNT, that in the limited number of cases reported thus far have had a 100% disease free survival.

Back to Top | Article Outline
146 Frequent Gain at Chromosome 1q Occurs in Atypical Meningioma but is a Poor Predictor of Likelihood of Recurrence

Michael Jansen1, Gayatry Mohapatra1, Catherine Keohane2, David Louis3. 1Pathology Service, Massachusetts General Hospital; 2Neuropathology, Cork University Hospital, Ireland; 3Pathology Service and Cancer Center, Massachusetts General Hospital

Atypical (WHO Grade II) meningiomas have moderately high recurrence rates; between 30 and 40% of completely resected tumors will recur. Thus, many patients receive post-operative radiotherapy (RT) to optimise local control and improve survival, but this carries the risk of side effects. More accurate prediction of recurrence risk might obviate the need for RT in some patients. Previously, we used high resolution array CGH to identify genetic variations in 47 primary atypical meningiomas and found that a greater proportion of tumours show gain of 1q at 1q25.1 and 1q25.3 to 1q32.1 (59%) than prevously documented and that 1q gain appears to correlate with shorter progression-free survival. We have now further investigated this association in a series of 101 atypical meningiomas (with 30 recurrences) from 2 neurosurgical centers in Ireland. Utilizing dual-color interphase FISH, 1q gain was assessed using BAC probes directed against 1q25 and 1q32. The results, which will be presented in detail, confirm the high prevalence of 1q gain in atypical meningiomas, and raise the possibility that assessment of 1q copy number status might provide clinically useful information for the management of patients with atypical meningiomas.

Back to Top | Article Outline
147 Sinonasal Teratocarcinosarcoma With Extensive Intracranial Involvement and Normal Chromosome 12p Status. A Case Report

Ada Baisre, James Liu, Gaurav Gupta, Manuel Cruz, Lisa Osborne, Neena Mirani. UMDNJ-New Jersey Medical School

Sinonasal teratocarcinosarcomas (SNTCS) were first recognized as an entity in 1984 and since then approximately 80 cases have been reported in the literature. The characteristic components include epithelial, mesenchymal and immature teratoma. We report a case of SNTCS in a 62-year-old man from Sri Lanka, who presented with headache, nasal stuffiness and epistasis. A biopsy was done in his native country and reported as Ameloblastoma. The patient came to the U.S., and by then he had developed confusion and change in mental status. On MRI there was an enhancing mass centered within the cribriform plate extending into the anterior cranial fossa causing severe mass-effect on the left frontal lobe, lateral ventricles, and corpus callosum, with extensive surrounding edema and infarctions in the inferior frontal lobes. Gross total resection was achieved by combined craniofacial and endoscopic sinonasal approaches. Morphologically the tumor included areas of squamous cell carcinoma, osteosarcoma, abundant immature neural components with rosettes in a neurofibrillary background, organoid structures, cartilage, clear cell "fetal appearing" squamous epithelium, adipose tissue and skeletal muscle among others. The tumor was attached the pial surface, however, frank brain invasion was not identified. Malignant germ cell components were not identified. Fluorescent in situ hybridization showed 2 copies of chromosome 12p. Regardless of the histogenesis of SNTCS remaining elusive, the absence of isochromosome 12p or any kind of amplification of chromosome 12p, which is a non-random genetic event associated with germ cell tumors, supports the current understanding that SNTCS are not germ cell neoplasms. SNTCS are rare and aggressive tumors that are commonly misdiagnosed on small biopsies because of their vast intratumoral heterogeneity and can extensively involve the brain.

Back to Top | Article Outline
148 Evaluation of Microscopic Criteria Used in Selection of Archived Meningiomas for Pending Studies of Tumor Genomes

Marie Beckner, Kristopher Katira, Raghu Sampath, Shashikant Patil, Mary Nordberg, Anil Nanda. Louisiana State University Health Sciences Center - Shreveport

Although most meningiomas are benign, some are atypical and aggressive. Molecular markers should enhance tumor evaluations but performance of investigative genomic studies to establish markers using large numbers of archived meningiomas is difficult. In view of the labor and costs involved in performing DNA studies on paraffin-embedded tissues, selection of small meningioma subsets with a high probability of yielding markers for aggressiveness is desired. Meningiomas resected by one surgeon, primarily at our institution, were examined microscopically to select a subset for pending molecular studies. Among 94 patients with tumors resected between 1992-2008, 91 patients with 105 meningiomas had slides available with diagnoses confirmed. Tumors from 17 patients were selected based on the following features: at least 4 mitoses/10 HPF (14 tumors from 12 patients), brain invasion (8 tumors from 7 patients) or a high proliferation rate (1 tumor) in any of each patient's resected meningiomas (24 original tumors or recurrences). Rhabdoid and chordoid variants were included. To confirm this group as significantly more atypical than most meningiomas, other WHO features of atypical meningiomas were compared on a 1 to 3 point scale in the selected and unselected (typical) groups of meningiomas. Loss of lobularity (sheeting), hypercellularity, cytologic atypia with macronucleoli, necrosis, small cell change and cellular anaplasia with pleomorphic, enlarged nuclei were found to be 2.40, 1.66, 4.08, 4.78, 5.10 and 2.10-fold greater, respectively, in the group of 24 tumors selected for DNA studies. The mitotic rate in the selected group was 4.458/10 HPF, representing a 9.27-fold increase over the mitotic rate in unselected (typical) meningiomas. Thus, 18.7% of the patients with meningiomas had tumors with microscopic features of atypia or aggressive behavior and warrant DNA studies to determine if new prognostic markers and therapeutic targets can be identified. We thank JoAnn Dismuke and Sherry Martin for assistance.

Back to Top | Article Outline
149 Intracranial Mesenchymal Chondrosarcoma: Light and Electron Microscopic Study of a Pediatric Case

Kun Jiang1, Yue Wang1, Mark Iantosca2, Melanie Comito3, Charles Specht1. 1Penn State - Hershey Medical Center; Dept. of Pathology; 2Penn State - Hershey Medical Center; Dept. of Neurosurgery; 3Penn State-Hershey Medical Center; Dept. of Pediatrics

Mesenchymal chondrosarcomas (MC) are bone-based malignant neoplasms of adults that rarely present as primary CNS tumors. Fewer than 20 pediatric cases of primary CNS MC have been reported. We studied an intracranial MC from an 18-month-old male by light microscopy (LM) and electron microscopy (EM). The patient was referred to Penn State-Milton S. Hershey Medical Center after several weeks of progressively worsening incoordination, emesis, and difficulty with ambulation. Imaging studies showed an enhancing, 7.0 × 6.3 × 5.5 cm complex cystic mass in the left parietal lobe. The patient became progressively obtunded with increasing intracranial pressure, and gross total excision of the tumor was performed. This white-tan, gelatinous tumor had cut surfaces that were focally hemorrhagic without necrosis. By LM, the highly-cellular tumor consisted of undifferentiated cells in a vascular stroma; there was focal chondroid differentiation. Pericellular and perivascular reticulin fibers were seen. Scattered tumor cells were positive for S100, GFAP, or p53, and chondroid foci were S100-positive. About 30% of the tumor cells were Ki-67-positive. The tumor was negative for EMA, NeuN, NFP, and synaptophysin. Reactivity for S100, GFAP and p53 are also features of extracranial chondrosarcoma. By EM, the tumor cells revealed minimal cytoplasmic differentiation, with RER and some intermediate filaments; basal lamina and intercellular junctions were absent. The stroma had poorly-developed collagen fibrils and focal features of a chondroid matrix. Because of the young age of this patient, he was treated postoperatively with chemotherapy, and is without recurrence nine months post resection. A literature review suggests that the extent of primary surgical resection is a major prognostic factor, and our experience indicates that gross total excision can be recommended as a primary therapeutic modality. Chemotherapy has been shown to increase survival in extracranial MC, and results thus far from our case support the value of that strategy.

Back to Top | Article Outline
150 Central Nervous System Amyloidomas Presenting With Progressive Cognitive Impairment

Matthew Hagen1, Merrill Benson1, Juris Liepnieks1, Thomas Witt2, Jose Bonnin3. 1Department of Pathology, Indiana University School of Medicine; 2Department of Neurosurgery, Indiana University School of Medicine; 3Indiana University School of Medicine

Isolated mass deposits of amyloid within the central nervous system are rare. We report a case of a 65-year-old female with a year-long history of progressive cognitive deterioration including attention, visuospatial, and procedural deficits as well as tremor in her hands. Magnetic resonance imaging of the brain revealed numerous foci of abnormal enhancement in multiple locations including the left frontal and parietal lobes, left centrum semiovale, both cerebellar hemispheres, left superior cerebellar peduncle, and walls of the fourth ventricle. The areas of enhancement were confluent within the deep white matter of the left parietal lobe, where they were associated with surrounding T2 prolongation with associated volume loss and without midline shift. The findings were suggestive of metastatic disease. Additional workup showed no evidence of a systemic malignancy. Stereotactic biopsies of the left parietal lesion were obtained. Histologically, it consisted of coarsely nodular masses of amorphous, congophilic material that showed apple-green birefringence when examined under polarized light, compatible with amyloid. Only a scant mononuclear cell infiltrate was associated with the deposits. Ultrastructural studies of the deposits showed the classical fibrillar pattern of amyloid and amino acid sequencing of the fibrils protein isolated from the paraffin embedded tissue revealed lambda light chain amyloid. A bone marrow biopsy showed a normocellular marrow with no evidence of increased plasma cells or a clonal lymphocytic proliferation. Further workup for plasma cell dyscrasia and systemic amyloidosis was negative. Less than 30 cases of central nervous system amyloidomas have been reported in the literature. The majority of them occurred in the supratentorial compartment and a few developed in the brain stem, preferentially in the periventricular region. In the present case, the deposits also involved both cerebellar hemispheres. No lesions were demonstrated in the spinal cord.

Back to Top | Article Outline
151 Intrathecal Ossifying Neurothekeoma or Nodular Arachnoiditis Ossificans: A Case Report.

Howard Chang. Neurology, Michigan State University

A 26-year-old woman presented with history of low back and left-sided pain. MRI of the lumbar spine revealed a 1-cm intrathecal mass in the left side of the spinal canal at the L1-L2 level. Gross total surgical excision of the tumor revealed a reddish tan firm, well circumscribed oval mass attached to a small nerve rootlet. The specimen was bisected to reveal irregular white gritty substance in the cut surfaces. A touch-preparation from the freshly cut surface revealed granules of dystrophic calcification and clusters of small spindle-shaped cells and epithelioid cells. A frozen section showed multiple calcified nodules surrounded by small spindle-shaped or epithelioid cells. After decalcification, the H&E stained paraffin sections showed multiple hypocellular nodules with pale blue chondromyxoid matrix. Some of these nodules had hollow central regions containing loose connective tissue and small vessels. Some nodules appeared contiguous with small bony fragments. These nodules were surrounded by small epithelioid cells with eosinophilic cytoplasm. Similar cells also formed small hypercellular nodules between the hypocellular chondromyxoid nodules. Small bundles of axons were found within the cellular region. No mitoses were seen.Immunohistochemistry showed that the most cells were positive for vimentin. The tumor cells were negative for CD10, EMA, S-100, muscle actin, GFAP, and CD68. Stain for neurofilament protein labeled the axons, as well as irregular profiles within the chondromyxoid nodules. The Ki67 labeling index was negligible, less than 1%. The overall features are those of a low-grade tumor. The negative immunoreactivity for S-100 and EMA indicate that this tumor is not schwannoma, neurofibroma, nerve sheath myxoma, perineurioma, or meningioma. Whether this is an unusual nodular arachnoiditis ossificans involving the nerve rootlet, an unusual intrathecal neurothekeoma, or another rare tumor, awaits experts' opinions.

Back to Top | Article Outline
152 Tuberous Sclerosis Complex and Langerhans Cell Histiocytosis in an 11 Month-Old Infant

Joshua Bradish1, Matthew Hagen1, Yi Zeng2, William Nunery3, Jose Bonnin4. 1Department of Pathology, Indiana University School of Medicine; 2Pediatric Hematology-Oncology, Indiana University School of Medicine; 3Oculofacial Plastic and Orbital Surgery, Indianapolis, Indiana; 4Indiana University School of Medicine

Tuberous sclerosis complex (TSC) is associated with multiple hamartomatous lesions and neoplastic processes, generally benign. We report an exremely uncommon occurrence of Langerhans cell histiocytosis (LCH) in an infant with stigmata of TSC. An 11 month-old previously healthy Hispanic infant presented with right eye bulging and periorbital erythema. A CT scan revealed a right orbital tumor with homogenous contrast enhancement and bone erosion that extended into the infratemporal fossa and the eyelid. A bone scan revealed abnormal uptake in the right orbit, cervical vertebrae and ribs. A biopsy of the orbital mass showed sheets of cells with irregularly grooved or wrinkled nuclei, moderate pleomorphism and pale amphophilic vacuolated cytoplasm intermingled with numerous eosinophils, sometimes forming small abscesses. The cells were positive for both S-100 protein and CD1a. There were no manifestations of diabetes insipidus. The child also had multiple hypomelanotic macules in the skin as well as radiological evidence of cortical tubers and subependymal nodules. Multiple cardiac rhabdomyomas were detected by ultrasound. CT scans of the chest and abdomen also revealed multiple small lesions in the lungs, liver and kidneys. They were considered hamartomatous and were not biopsied. The patient is currently undergoing chemotherapy for LCH. The simultaneous occurrence of the two diseases in this patient is unusual. Since there is no increased incidence of lymphoproliferative or histiocytic disorders in TSC, it is quite unlikely that patients with tuberous sclerosis have a predisposition to develop LCH. While the incidence of tuberous sclerosis is 1 in 6000 newborns, the simultaneous occurrence of LCH is extremely rare. To our knowledge, there is only one similar case previously reported in the literature.

Back to Top | Article Outline
153 Primitive Neuroectodermal Tumors of the Leptomeninges Mimicking Meningitis: A Report of Two Cases

Kathy Newell. University of Kansas Medical Center, Department of Pathology

Primitive neuroectodermal tumors (PNET) of the brain may show secondary spread within the subarachnoid space, but primary central nervous system (CNS) PNETs of the meninges are extremely rare. We describe the findings in 2 cases of PNET, apparently primary to the leptomeninges. A 73 year-old man with progressive lower extremity weakness underwent MRI which revealed enhancing areas of leptomeninges along the base of the brain and cervical and lumbar spinal cord, suspicious for an inflammatory or infectious meningeal disorder. After numerous uninformative laboratory studies, laminectomy for biopsy of a focus of cervical enhancement was undertaken. A 46 year-old man with a 2 month history of chronic headache developed photophobia, nausea, vomiting, and back pain. Spinal fluid revealed leukocytosis and MRI studies of the brain and spinal cord identified linear to nodular enhancing, thickened areas of the meninges, clinically suspicious for meningitis. Cultures were negative, and other laboratory studies did not suggest an etiology. Cerebral edema progressed to tonsillar herniation and death. No significant pathological findings were identified in the general autopsy examination. A diffuse infiltrate of atypical primitive cells centered in the subarachnoid space lining the spinal cord and brain. Histologically similar cells were identified in the arachnoid biopsy from the 73 year-old man. The neoplastic cells from both cases showed similar immunoreactivity profiles (positive for CD56, CD57, negative for CD99). No other primary site for the neoplastic cells was identified in the 46 year-old man. As with the 3 cases described by Dr. Kepes (Clin Neuropathol 1985;4:1-11) there was no detectable primary intracranial neoplasm in either subject, neither by imaging studies (both) nor autopsy evaluation (46 year-old man). In each case, the distribution and immunohistochemical profile of the neoplastic cells support the diagnosis of CNS PNET, apparently primary to the leptomeninges, an extremely rare tumor.

Back to Top | Article Outline
154 Multiple Epstein-Barr Virus-Associated Smooth Muscle Tumors in a Pediatric Patient Following Renal Transplantation

Syed Kazmi1, Michele Aizenberg2, James Harper3, McComb Rodney1. 1Dept. of Pathology and Microbiology, Univ. of Nebraska Medical Center; 2Dept. of Neurosurgery, University of Nebraska Medical Center; 3Dept. of Pediatrics, University of Nebraska Medical Center

Epstein-Barr virus-associated smooth muscle tumors (EBV-SMT) are rare lesions that occur in immunocompromised patients. Causes of immunosuppression include AIDS, organ transplantation, and steroid therapy. Anatomical sites of these tumors have included the lungs, gastrointestinal tract, subcutis, liver, retroperitoneum, vertebral body, adrenal gland, and dura. Dural involvement is more common in HIV patients than in organ transplant recipients, where only a few cases of dural-based EBV-SMT have been reported. Majority of these tumors is multifocal, whereas analysis of clonality showed different clones in tumors from different sites. We describe a case of an 8-year-old female who presented with adrenal, small bowel and intracranial tumors six years following living related donor renal transplantation for congenital bilateral renal dysplasia. MRI of the brain showed two enhancing hemorrhagic extraaxial masses in the right frontal area. At surgery, both masses were well circumscribed and dural-based without brain invasion. Histopathological analysis revealed a highly cellular spindle to round myoid cell neoplasm with numerous mitoses (up to 15 per 10 hpf). Tumor focally demonstrates a hemangiopericytoma-like vasculature. Necrosis was not seen. The tumor stained diffusely for smooth muscle actin. CD34 and EMA were negative. Epstein-Barr virus (EBV) was demonstrated within the neoplastic nuclei by in situ hybridization for EBV-encoded RNA (EBER). This tumor would be classified as leiomyosarcoma using traditional criteria for smooth muscle tumors. However, due to the paucity of reported cases following organ transplantation, the natural history of these lesions is unclear and little is known about the prognosis and optimal treatment of EBV-SMT in this setting.

Back to Top | Article Outline
155 Rosai-Dorfman Disease of the Sellar Region With Multiple Intracranial Recurrences: Report on Two Cases

Fulin Wang, Xin Lou, Guangyu Qiao. Chinese PLA general hospital

Two patients presenting sellar region extranodal Rosai-Dorfman Disease (RDD) with multiple intracranial recurrences are described. A 10-year-old girl presented with 1 year history of polydipsia and polyuria. MRI revealed a sellar mass arising from posterior pituitary gland. The patient underwent trans-oronasosphenoidal microsurgical exploration. Histopathology was compatible with RDD. The patient followed by radiotherapy. Five months later the patient complained of recurrence of the symptoms. MRI showed two masses differently located in the third ventricular and suprasellar region. Nine months later repeated MRI showed a lobulated lesion in anterior horn of the right lateral ventricular. Additionally, head of right caudate nucleus, anterior limb of right internal capsule and rostrum and genu of corpus callosum were involved. Corticosteroid agents were administrated. Recent Following-up MRI demonstrated marked resolution of the multiple lesions. A 27-year-old man presented with 1 year history of polydipsia and polyuria. MRI disclosed a mass in sellar region. The patient underwent microsurgical treatment by transsubfrontal-sphenoidal approach. Histopathology was consistent with RDD. One year later the patient complained of recurrence of the symptoms. The laboratory investigation showed evidence of hypopituitarism. Corticosteroid agents were administered for 6 months. Three years and 7 months later MRI disclosed multiple intracranial sites of involvement. Radiotherapy and corticosteroid agents were administered. A Follow-up MRI disclosed near-complete resolution of the lesions and corticosteroid agents were gradually tapered. These two cases and cases from the literature demonstrate that intracranial RDD with multiple intracranial recurrences postoperatively corticosteroid agents should be advisable.

Back to Top | Article Outline
156 A Case of Adrenomyeloneuropathy with Frontal Lobe Type Dementia

Namita Sinha1, John Wherrett2, Sidney Croul2. 1University of Toronto, Dept. of Lab Medicine and Pathobiology; 2University of Toronto

Adrenomyeloneuropathy is a phenotype of X-linked Adrenoleukodystrophy, a disorder of peroxisomal β oxidation. It is characterized by accumulation of very-long-chain fatty acids leading to damage of central and peripheral myelin, adrenal glands and gonads. We describe an interesting case of adrenomyeloneuropathy with frontal lobe type dementia who presented at the age of 23 with features of hypogonadism, adrenal insufficiency and developed gait abnormality and dementia late in the disease course. His two brothers died of adrenoleukodystrophy at an early age. Our patient died at 68 years of age and an autopsy revealed bilateral adrenal atrophy and marked atrophy of brain predominantly involving centrum semiovale, parieto occipital white matter, brainstem and spinal cord.

Back to Top | Article Outline
157 Primary Central Nervous System Lymphoma Presenting as a Solitary Brainstem Lesion in an Immunocompetent Adult

Kimberly Stogner-Underwood, Gary Tye, Christine Fuller. Virginia Commonwealth University Health System

Primary central nervous system lymphomas are generally high grade large B-cell neoplasms, and most commonly arise in either immunocompetent older adults or immunocompromised patients of any age. They usually occur in a supratentorial location. We present a case of a 48 year old immunocompetent, HIV negative man with no significant past medical history, who developed weakness, blurry vision, nausea, vomiting, dysphagia, and weight loss. MRI confirmed a well-circumscribed 2 cm contrast-enhancing mass arising from the floor of the fourth ventricle with invagination into the lower pons and medulla; there was associated edema in the medulla and cerebellum. The differential diagnosis initially being entertained based on the location and radiographic appearance included ependymoma, astrocytoma, metastasis, medulloblastoma/PNET, and hemangioblastoma. Histologic examination and immunohistochemical studies performed on brainstem biopsy material however were indicative of a high grade large cell B-cell lymphoma. The neoplastic cells were immunopositive for CD20, bcl-2, bcl-6, MUM-1, CD79a, and pax-5, and negative for CD3, CD30, CD34, and myeloperoxidase. A bone marrow biopsy was negative for lymphoma, and no evidence of systemic lymphoma was identified on examination or additional imaging studies. Following surgical resection, the patient was treated with high dose methotrexate and intrathecal chemotherapy. No evidence of tumor recurrence was seen on imaging at 2.5 months post surgery; however, he has required a PEG tube for persistent dysphagia. This case is unusual in terms of the location of the tumor, young age of the patient, and lack of a predisposing immune compromised state.

Back to Top | Article Outline
158 Immunohistochemical Analysis of INI1 in a Retrospective Study of the Central Nervous System Tumors With Embryonal Morphology

Maria Gorgan1, Keyla Kleyser-Sugrue2, Xianyuan Song1, Deborah Stevens1, Richard Cartun1, Thomas Ciesielski1, Srinivas Mandavilli1. 1Hartford Hospital; 2Hartford Hospital, Hartford Connecticut

INI1 is a tumor suppressor gene with a consistent loss of expression in atypical teratoid/rhabdoid tumors (AT/RT). In the absence of rhabdoid features, the diagnosis of AT/RT can be challenging and such cases can be misclassified as medulloblastoma/PNET or high-grade glioma. Recent literature suggests use of INI1 in the immunohistochemical (IHC) analysis of pediatric CNS tumors with embryonal morphology. There is limited literature regarding INI1 expression in such tumors in older children and adults. It is unclear whether it needs to be part of the IHC work-up in CNS tumors with an embryonal morphology, regardless of patient age. The current study evaluates the expression of INI1 in CNS tumors with embryonal morphology in patients with a wide age range. We retrieved all CNS tumors with an embryonal morphology from our institution's files from 2000 to 2009, which resulted in 18 cases (six males and 12 females). The age range was 5 weeks to 43 years. INI1 IHC stains were performed. Two cases (11%, age of 5 weeks and 2-year old, respectively) show complete loss of INI1, confirming the diagnosis of AT/RT. The rest of the 16 cases (89%, age 5 to 43 years) showed diffuse nuclear positivity for INI1 in the malignant cells. Of these 16 cases, two had epithelioid/glandular foci, consistent with choroid plexus carcinoma. The other 14 cases were cerebellar/posterior fossa tumors morphologically typical of medulloblastoma. Our results show that all the CNS tumors with an embryonal morphology in patients greater than 5-year old displayed intact INI1 expression, excluding the diagnosis of AT/RT. The only two cases of AT/RT were less than 2 years of age, (confirmed with negative INI1 expression). Based on this study, INI1 IHC does not appear to be warranted in the work up of CNS tumors of embryonal morphology in older children and adults.

Back to Top | Article Outline
159 Inhibition of Placental Growth Factor (PlGF) Leads to Regression of Medulloblastoma

Matija Snuderl1, Nathaniel Kirkpatrick2, Elisa Walsh2, Euiheon Chung2, Walid Kamoun2, Teresa Peterson2, Dan Duda2, Dai Fukumura2, Peter Carmeliet3, Lei Xu2, Rakesh Jain2. 1Pathology Service Massachusetts General Hospital; 2Department of Radiation Oncology, Massachusetts General Hospital; 3Department of Transgene Technology and Gene Therapy, K.U. Leuven

Introduction: Medulloblastoma contains a rich and abnormal vascular network offering a potential target for anti-angiogenic treatment. However, current antiangiogenic drugs offer little to pediatric patients due to serious adverse effects. Here, we examine the role of placental growth factor (PlGF), another angiogenic mediator, in medulloblastoma growth and as a target for therapy.

Methods: Tissues collected from 5 pediatric medulloblastomas and 4 adult cerebelli were screened for 96 genes associated with angiogenesis using a PCR array. Immunohistochemistry was performed on 14 formalin fixed paraffin embedded (FFPE) medulloblastoma samples. D283Med and D341Med human medulloblastoma cells were transfected with Gaussia luciferase cDNA and implanted orthotopically into cerebelli of SCID mice. Tumor growth was followed by whole body imaging and blood Gluc assay. Tumor-derived PlGF was blocked by anti-PlGF antibody (PL5D11D4, ThromboGenics) or silenced by siRNA. WST-1 Cell Proliferation Assay was performed to explore direct effects of anti-PlGF Ab in vitro.

Results: PlGF was not expressed in adult cerebelli and was overexpressed in all medulloblastoma tissues by PCR. Twelve of fourteen (85%) FFPE medulloblastomas showed expression of PlGF by immunohistochemistry. Mice with implanted medulloblastoma cells with PlGF silenced by siRNA or blocked by the antibody from the day of implantation showed a significant delay in tumor growth (p < 0.0001) and prolonged survival (p = 0.003) when compared to IgG-treated controls. Treatment of established tumors 3 weeks post-implantation with anti-PlGF antibody showed stabilization of disease and regression of medulloblastomas (p = 0.017) by Gluc and whole body imaging measurements, and prolongation of survival (p = 0.0009). There was no direct effect of anti-PlGF treatment on tumor cells in vitro.

Conclusion: PlGF is overexpressed in medulloblastomas. Mice bearing orthotopic tumors showed significantly delayed tumor growth and longer survival after PlGF inhibition. Thus, PlGF targeting may provide a safe and efficient therapy for pediatric medulloblastoma.

Back to Top | Article Outline
160 Utility of the Presence of Brain Tissue as a Surrogate Marker of Brain Invasion in Predicting Recurrence in Meningiomas

Fahad Bafakih1, Salwan Almashat2, Kenneth Fallon3, Kymberly Gyure1. 1West Virginia University; 2Beth Israel Deaconess Medical Center; 3University of Alabama at Birmingham

The presence of brain invasion in patients with meningiomas connotes a greater likelihood of recurrence and may be seen in histologically benign (grade I), atypical (grade II), or anaplastic/malignant (grade III) tumors. Brain invasion is characterized by the infiltration of surrounding tissue by tongue-like protrusions of tumor cells without an intervening layer of leptomeninges. The presence of tumor along perivascular spaces is thought not to qualify as true invasion and may make the evaluation of the presence or absence of brain invasion difficult in individual cases. To determine whether or not the mere presence of brain tissue in resection specimens might correlate with recurrence and therefore serve as a relatively simple to determine surrogate marker of brain invasion, we evaluated a series of 61 consecutive patients with meningioma resections in whom adequate clinical follow-up information was available. These included 51 grade I, eight grade II, and two grade III lesions. Fragments of brain tissue were identified in 19 cases, seven of which also had unequivocal brain invasion. Five of these 19 patients (26%) experienced recurrences an average of 62 months following surgery. Four of the patients with recurrences also had brain invasion, and four had grade II lesions. Overall, eight of the 61 patients (13%) experienced recurrences, seven of whom had grade II lesions. Only one of the 12 patients whose slides exhibited brain tissue without definitive brain invasion experienced a recurrence; this patient had a grade II lesion. In our series, tumor grade was the best predictor of recurrence; seven of eight patients with recurrences had grade II lesions. In the absence of unequivocal brain invasion, the presence of brain tissue in meningioma resection specimens does not correlate with recurrence.

© 2010 American Association of Neuropathologists, Inc

Login