Poster Abstracts Presented at the 24th Virtual Joint Meeting of The International Society of Dermatopathology, April 12–16, 2021 : The American Journal of Dermatopathology

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Poster Abstracts Presented at the 24th Virtual Joint Meeting of The International Society of Dermatopathology, April 12–16, 2021

The American Journal of Dermatopathology 43():p 1-14, August 2021. | DOI: 10.1097/DAD.0000000000002030
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Poster Abstracts Presented Monday–April 12, 2021

A Case of Salivary Gland Hyalinizing Clear Cell Carcinoma (HCCC) With Cutaneous Metastasis

Rand Abou Shaar, MD,* Shereen Zia, MD,* Mohamed Alhamar, MD*, and Ben J. Friedman, MD*,†

Departments of *Pathology and †Dermatology, Henry Ford Health System, Detroit, MI.

Hyalinizing clear cell carcinoma (HCCC) is a rare malignant tumor of the minor salivary glands with low-grade morphology and generally favorable outcome. In up to 16.4% of cases, aggressive disease and metastasis has been reported.  We report the case of a 44 year-old female with history of HCCC arising at the base of her tongue which had the typical   EWSR1-ATF1 fusion. She received wide local excision followed by adjuvant radiation, chemotherapy and immunotherapy. However, over the following few years, the tumor metastasized to multiple visceral sites. Interestingly, she also developed two closely adjacent nodules on her scalp which demonstrated variably sized aggregations of atypical pale-cuboidal cells with surrounding sclerosis filling the dermis and abutting the epidermis, morphologically resembling her previously known HCCC. To our knowledge, this is the first reported case HCCC with cutaneous metastasis, which is noteworthy because it can cause diagnostic confusion given the morphologic and immunophenotypic similarity to other primary skin adnexal tumors.

Fixed Drug Eruption Unresponsive to Doxycycline

Syeda Fatima Absar, MD, MPH,* Raj Patel, MD,† Eric Hossler, MD,* and Wells Chandler, MD*

*Department of Pathology, Geisinger, Danville, Pennsylvania; and †Department of Dermatology, Geisinger, Danville, Pennsylvania.

A 66-year-old female was seen in the dermatology clinic for a recurrent bull's-eye patch on the thigh that had accentuated five times in six months. Her primary care physician suspected erythema migrans and prescribed doxycycline as she had additional complaints of fatigue, night sweats and weight loss. After the antibiotic course, she presented to the dermatology clinic with a light brown erythematous patch on her left thigh (Figure 1). A punch biopsy showed subtle vacuolar interface dermatitis with mild melanin pigment incontinence and scant eosinophils, suspicious for a quiescent fixed drug eruption (Figures 2, 3, 4). Six weeks later she returned and the brown patch was now an erythematous plaque (Figure 5). She had ingested ibuprofen one week earlier and naproxen the previous day. A punch biopsy showed characteristic features of an active and intense fixed drug eruption (Figures 6, 7, 8). Attention to the periodicity of the rash and prompt clinical follow-up during an acute episode was critical to establishing the correct diagnosis.

Invasive Melanoma Presenting as Anal Discharge

Anupma Agarwal, MD, MA, Weihua Song, MD, PhD, Kokila Mody, MD, and Jocelyn Villanueva, MD

Department of Pathology and Laboratory Medicine, Staten Island University Hospital, Staten Island, NY.

Primary anal melanoma represents less than 1% of all gastrointestinal malignancies and has a poor prognosis. We present a 72 year old male with history of hypertension and bladder cancer in remission who presented with anal discharge and tenesmus for 2 months. Examination revealed internal and external hemorrhoids with a 5 × 2 cm pedunculated freely mobile black mass. Wide local excision revealed a primary invasive nodular melanoma composed of epithelioid and spindled cells with foci of pigmentation. The tumor was 13 mm in maximum thickness, with a mitotic rate of 20-30 mitoses/mm2. Perineural invasion was identified. The resection margins were not involved. Next generation sequencing reported a missense mutation in KIT (p.Leu576Pro). The patient was started on immunotherapy. A 7-month follow up revealed progression of disease. Biopsy of left and right groin lymph nodes revealed metastatic spindle cell melanoma on both sides. We reiterate the aggressiveness, poor prognosis, and high stage of anal melanomas at diagnosis, because of a concealed location and non-specific symptoms.

Pancreatic Adenocarcinoma Presented as Nodule Of Sister Mary-Joseph

Maryam Aghighi, MD,*,1, Mohammad Bagher Shokravi, MD,† and Maral Rahvar, MD‡

*Department of Pathology, Rutgers Robert Wood Johnson Barnabas Health, Livingston, NJ; †M.B. Shokravi Office, North Vancouver, BC, Canada; and ‡Department of Pathology and laboratory medicine, University of British Columbia, Vancouver, BC, Canada.


Background: Sister Mary-Joseph nodule is an uncommon metastasis to umbilical skin from internal tumors. Metastasis from pancreatic cancers is rarely reported. We report a case of metastatic pancreatic adenocarcinoma to umbilical skin.

Case Presentation: An 85-year-old female presented with a 1.8 cm protrusion of the right lateral umbilicus. CT revealed a 3.5 cm pancreatic mass, peritoneal carcinomatosis and abdominal lymphadenopathy.

Results: Histologically, there were atypical infiltrative glandular structures, positive for CK7, negative for CDX2 and P53 with mutated pattern which were consistent with metastatic adenocarcinoma. Pancreatobiliary or upper GI origin was favored.

Conclusions: In pancreatic ductal adenocarcinoma, CK7 highlights the ductal cells. Intestinal type adenocarcinoma expresses CDX2 whereas pancreatic ductal adenocarcinoma is negative for CDX2. Pancreatic mass in CT, CK7 positivity and CDX2 negativity in umbilical nodule tumor cells suggest the diagnosis of adenocarcinoma in the current case.

Therapy-Related Myeloid Sarcoma (T-MS) of the Skin (T-AML) with NPM1 Mutation Gained at Time of Leukemic Transformation

Meghana Agni MD,* Arjun Dayal MD,† Angad Chadha MD,† Angela Lager PhD,* Peng Wang MD,* Michael J. Thirman MD,‡ Chris Daugherty,‡ and Elizabeth Hyjek MD*

*Department of Pathology, Sections of †Dermatology and ‡Hematology/Oncology, Department of Medicine, University of Chicago, Chicago, IL.

A 77 y/o man with history of esophageal and lung carcinoma treated with radiation/resection and radiation, respectively, presented with therapy-related myeloid neoplasm (t-MN) with 12% blasts, myelomonocytic differentiation, and ASXL1, SETBP1, SRSF2, TET2, and NRAS mutations in the bone marrow (BM), preceded two years earlier by clonal hematopoiesis of indeterminate potential (CHIP) with the same mutations. At the time of t-MN diagnosis, he developed widespread blastic skin lesions with persistence of the same mutations plus gain of NPM1 mutation, consistent with t-MS (t-AML) with mutated NPM1. NGS analysis of t-MS, additionally detected KRAS mutation and CDKN2A loss, possible contributors to leukemic transformation. AML with mutated NPM1 usually presents as de novo AML. This is a rare occurrence of t-MN with “secondary-type” mutations progressing to t-MS (t-AML) with gain of NPM1 mutation at the time of leukemic transformation.

A Newly Described Hamartoma Associated With Tuberous Sclerosis Complex

Meghana Agni, MD* and Oluwakemi Onajin, MD†

*Department of Pathology and †Section of Dermatology, University of Chicago, Chicago, IL.

We report a case of a 23-year-old man with tuberous sclerosis complex (TSC) who presented with a long-standing scalp lesion. Physical examination revealed multiple angiofibromas on the face and a large, firm, skin-colored alopecic plaque with superimposed comedones, nodules, and cysts on the posterior vertex scalp. A biopsy revealed an exophytic lesion composed of thickened collagen bundles with stellate fibroblasts and concentric arrangement of collagen around adnexal structures. Keratin-filled infundibular cysts, and ruptured cysts demonstrated granulomatous and suppurative inflammation with naked hair shafts. These clinical and histopathologic findings were consistent with folliculocystic and collagen hamartoma (FCCH). FCCH is a rare, newly described entity that is associated with TSC. It was first described in 2012, by Torrelo et al., and to date, only 12 cases have been reported in the literature. Ten of the cases were in patients with TSC, and 10 of the patients were male, corroborating a strong association with TSC and male predominance. We present an additional case of a rare, under-recognized complex hamartoma associated with TSC.

Indeterminate Dendritic Cell Tumor With Braf-Positivity

Meghana Agni, MD,* Kristen M. Paral, MD,† Thomas Krausz, MD,* and Aaron Miller, MD*

*Department of Pathology, University of Chicago, Chicago, IL and †CPC Pathology, Libertyville, IL.

An 81-year-old man presented with a right posterior scalp lesion. The shave biopsy revealed a neoplasm, comprising large, discohesive, histiocytoid cells in the dermis, with limited “pagetoid” spread in the epidermis. The morphology suggested Langerhans cell histiocytosis (LCH) as the main diagnostic consideration, and immunohistochemistry was performed resulting in S-100 and CD1a positivity. However, subtle features deviated from LCH; tumor cells had mostly round, eccentric nuclei with variably prominent nucleoli. Nuclear grooves and reniform-shaped nuclei, seen in LCH, were limited. Moreover, the absence of significant inflammatory infiltrate, including eosinophils, did not fit with LCH. Ultimately, Langerin stain was negative, which excluded a diagnosis of LCH and provided a histopathologic picture consistent with indeterminate dendritic cell tumor (IDCT). IDCT is a rare neoplasm characterized by a dendritic cell proliferation that mimics Langerhans cells immunophenotypically (CD1a and S-100 positivity), but lacks LCH's characteristic Birbeck granules. Our case also demonstrated a BRAF V600E mutation, only reported in six other cases of IDCT. We present another example of this uncommon entity.

Pineoblastoma With Cutaneous Metastases

Hana Ahmed, MD, Danielle Fasciano, DO, Martin Hatch, MD, Alison Burkett, MD, Blake Phillips, MD, Peter Pavlidakey, MD, and Carly Elston, MD

UAB, Birmingham, AL.

Pineoblastomas are rare, high-grade pineal parenchymal tumors that infrequently metastasize extraneurally, with no known reported cases of cutaneous metastasis. We herein report a rare case presentation. A 50-year-old male presented with an asymptomatic nodule of his left cheek, present for 2–3 weeks. Relevant past medical history included pineoblastoma, diagnosed approximately 20 years prior and previous melanoma of the upper back. Based on the clinical history and high suspicion for metastatic disease, the lesion was treated with surgical excision. Histopathology revealed a poorly differentiated neoplasm consisting of hyperchromatic small round blue cells that were noncontiguous with the overlying epidermis or adnexal structures. Immunohistochemical staining demonstrated positive staining for chromogranin and synaptophysin, consistent with metastatic pineoblastoma. After excision, the patient was continued on his chemotherapy and radiotherapy regimen. This case highlights the aggressive nature of pineoblastoma. While CSF dissemination is common in this entity, cutaneous metastases have not yet been reported. This case highlights the importance of having a high degree of clinical suspicion when evaluating skin lesions in this patient population.

Atypical Aphthous-Like Oral Pemphigus in a Liver Transplant Patient

Nora S. Ali, MD, Nessa Aghazadeh Mohandesi, MD, Lawrence E. Gibson, MD, and Margot S. Peters, MD

Mayo Clinic Department of Dermatology, Rochester, MN.

A 56-year old woman, 6-years post liver transplantation, on oral tacrolimus, presented for evaluation of painful oral ulcers. No oral lesions were present on two previous evaluations. Indirect immunofluorescence (IIF) and ELISA for desmoglein (DSG) 1, DSG3, bullous pemphigoid (BP) 180 and BP230 were negative twice. She subsequently presented with aphthous-like erosions: two biopsies showed suprabasilar acantholysis and sloughing above the basal layer; direct immunofluorescence (DIF) revealed IgG and C3 deposition on epithelial cell surfaces and the basement membrane zone (BMZ) in a linear pattern. ELISA for BP180, BP230, DSG1, and DSG3, and IIF on monkey esophagus and rat bladder were negative. Histopathology and DIF findings of cell surface antibodies, in context with the clinical course, supported diagnosis of the rare aphthous-like pemphigus, especially atypical with the additional DIF finding of BMZ antibodies. She was treated with fluocinonide gel. We postulate the absence of circulating antibodies with mild clinical disease relates to immunosuppression with tacrolimus. This case highlights the delay in diagnosis associated with aphthous-like pemphigus vulgaris.

Pecoma Arising in the Buttock Region: A Call for Increased Awareness of This Tumor

Rafey Rehman, BS,* Mariam Aoun, BS,* Ronald Levitin, MD,† Thomas J. Quinn, MD,† and Peyman Kabolizadeh, MD, PhD†

*Oakland University William Beaumont School of Medicine, Rochester, MI; and †Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI.

Introduction: Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors that have a perivascular distribution. To our knowledge, this is the only reported instance of PEComa in the buttock region presenting with symptoms of discomfort.

Methods: We report a 49-year-old female who presented with a 2-month history of an enlarging mass on her right buttock and discomfort while sitting. Imaging revealed a soft tissue mass with central necrosis, and a small mass in the left upper lobe of the lung. Biopsy with pathology demonstrated high-grade malignancy and epithelioid cells that had clear to eosinophilic cytoplasm. Final pathology during surgical resection confirmed the diagnosis of a PEComa. Neoadjuvant radiation therapy was administered, followed by surgical resection. Repeat imaging after intervention revealed development of diffuse bilateral nodules, necessitating chemotherapy.

Results: Follow-up imaging showed mixed response with substantial improvement in the intrathoracic disease burden, but progression of disease elsewhere.

Conclusions: Early diagnosis and treatment is crucial in improving outcomes in patients with PEComa.

Cutaneous T-Cell Lymphoma in SHOC2 Mutation Associated Noonan-Like Syndrome With Loose Anagen Hair

Alexandria Avery, John Metcalf, John Maize, and Leah Swanson

MUSC, Charleston, SC.

Noonan-like syndrome with loose anagen hair (NS/LAH) is a newly described rare disorder caused by a mutation in SHOC2 which modulates the RAS/MAPK signaling pathway. NS/LAH has features overlapping with other RASopathies including cardiac defects, macrocephaly, central nervous system anomalies, and short stature with the addition of loose anagen hair and atopic dermatitis. A 25-year-old man with NS/LAH presented with a several-year history of a pruritic eruption recently treated as atopic dermatitis with dupilumab. On examination he had hyperpigmented patches and lichenified plaques involving the face, trunk, and extremities. Biopsy revealed an atypical epidermotropic and superficial dermal infiltrate of CD4+ T-lymphocytes. T-cell receptor gene rearrangement PCR was negative for clone. Clinical and histopathologic features were consistent with cutaneous T-cell lymphoma (CTCL). Tumor predisposition disorders are well described in RAS/MAPK syndromes. However, few malignancies, including neuroblastoma and myelofibrosis, have been reported in NS/LAH. This is the first report of CTCL in NS/LAH. These findings expand the phenotypic description of NS/LAH. Additionally, in the context of dermatitis reported with NS/LAH, dupilumab could pose a risk for CTCL progression.

“Linear IGA Bullous Dermatosis Resembling Toxic Epidermal Necrolysis”

Alexandria Avery, DO, Sally Self, MD, Laura S. Winterfield, MD, MPH, and Jessica A. Forcucci, MD

Medical University of South Carolina, Charleston, SC.

Linear IgA bullous dermatosis is a rare mucocutaneous blistering disease, characterized by IgA basement membrane autoantibodies. We present a case of clinically unsuspected linear IgA bullous dermatosis mimicking toxic epidermal necrolysis (TEN)/Stevens-Johnson Syndrome (SJS). A 65 year old man with past medical history of liver transplant was admitted for fevers of unknown origin and altered mental status. During hospitalization, the patient developed a diffuse blistering eruption and mucositis. Dermatology was consulted and a biopsy was performed given clinical suspicion of TEN/SJS. Chart review revealed multiple new medications including meropenem, vancomycin, and doxycycline. The biopsy demonstrated a subepidermal vesicle with neutrophils, and a microscopic differential diagnosis of linear IgA bullous dermatosis, drug eruption, and bullous lupus erythematosus. Additional biopsies, including direct immunofluorescence (DIF), were suggested to clarify the diagnosis and exclude sampling error given the clinical impression of TEN/SJS. Subsequent biopsy demonstrated similar findings and 2+ linear basement membrane deposition of IgA on DIF. Unfortunately, the patient died two days later. Autopsy revealed disseminated mycobacterial infection, and cause of death was deemed complications of transplantation.

Carcinoma En Cuirasse: A Rare Presentation of Salivary Gland Carcinoma

Daniel Bergman, MD and David J. DiCaudo, MD

Mayo Clinic Scottsdale, Arizona.

A 57-year-old man, with a history of a high-grade salivary neoplasm, presented with a painful rash of four months duration. Physical exam revealed a massive, well-circumscribed violaceous to salmon-colored woody plaque circumferentially encompassing the neck and broadly extending over the left chest and left scalp. A punch biopsy showed malignant epithelioid cells of metastatic carcinoma invading dermal vessels and diffusely infiltrating the dermis and subcutis. Taken together, the clinical and histopathologic findings confirmed a diagnosis of carcinoma en cuirasse. Immunohistochemistry was diffusely positive for androgen receptor, GATA 3, and CK7. HER2 expression was equivocal. Genomic findings included NF1/PTEN/RAD21/TP53 alterations. Although not specific, the above results were compatible with the patient's history of high-grade salivary gland carcinoma. Oncology offered chemotherapy, but the patient declined and succumbed to his illness two months later. Carcinoma en cuirasse is a rare presentation of cutaneous metastasis typically seen in breast carcinoma. Herein we report, to our knowledge, the second case of carcinoma en cuirasse due to a salivary gland tumor. The prognosis of cutaneous metastatic lesions is poor with a median survival of 7.5 months.

Mycobacterium Chelonae Mimicking Erythema Nodosum in Immunosuppressed Patient With COVID-19

Emily Bolton, MD, Matthew Dizon, MD, Sujeet Govindan, MD, Jesse Keller, MD, and Kevin White, MD

Oregon Health & Science University, Portland, OR.

Clinical History: A 68 year old man with sarcoid on adalimumab and prednisone was admitted with cough and fever from COVID-19. He had indurated red, purple-brown nodular plaques on the right medial knee and shin. His clinical picture was suspicious for erythema nodosum.

Histopathological Result and Tests: A 4-mm punch biopsy revealed suppurative and granulomatous dermatitis with necrosis. Gram and AFB staining showed gram positive/AFB-positive filamentous bacteria within areas of necrosis. The filamentous appearance and clinical picture was suspicious for cutaneous nocardia. Initial biopsy and two additional 4 mm punch biopsies sent for bacterial, fungal, acid-fast culture, and broad range PCR, identified mycobacterium chelonae.

Discussion: Mycobacterium chelonae (MC) is a rapidly growing non-tuberculous mycobacterium (NTM). NTM are a heterogenous group of environmental organisms. MC mainly causes disease in immunocompromised patients. Diagnosis is based on tissue culture. With gram and AFB staining, NTM can appear filamentous and similar to nocardia, creating potential for misdiagnosis. Treatment consists of induction and maintenance therapy, with 2-3 antibiotics.

BRAF and MEK Inhibitor Induced Granulomatous Dermatitis During the Treatment of Cholangiocarcinoma

Jordan L. Bormann, BA,* and Amy M. Kerkvliet, MD†

*University of South Dakota Sanford School of Medicine, Sioux Falls, SD; †University of South Dakota Sanford School of Medicine, Department of Pathology, Sioux Falls, SD.

Granulomatous Dermatitis (GD) has been described as a rare side effect of MEK and BRAF inhibitor use in the treatment of BRAF V600E positive metastatic melanoma. However, to the best of our knowledge, there have been no reported cases of GD in the treatment of BRAF V600E positive cholangiocarcinoma treated with BRAF and MEK inhibitors. Here we present the case of a 52 year old woman enrolled in a clinical trial who was treated with vemurafenib and cobimetinib for BRAF V600E mutation positive metastatic cholangiocarcinoma. During treatment, nonpalpable, violaceous areas of mottling on the medial aspects of the patient's legs and arms developed. Biopsies of the lesions were consistent with GD and revealed non-necrotizing granulomas in the superficial dermis extending into the subcutaneous adipose tissue with surrounding chronic inflammatory infiltrate and rare eosinophils. Within 2 months from onset, the lesions resolved without any medication use or interruption in scheduled BRAF and MEK inhibitor therapies.

Investigating SOX10 Positivity in Benign Cutaneous Ulcerations

Geoffrey Chen, MS and Kumaran Mudaliar, MD

Loyola University Medical Center, Maywood, IL.

Background: SOX10 is an immunohistochemical stain used by dermatopathologists for its sensitivity in highlighting melanocytes. However, there have been reports of non-specific SOX10 positivity. A recent case of a benign cutaneous ulceration contained SOX10 positive cells in the upper layers of the dermis adjacent to ulceration. Although the clinical context did not raise suspicion for melanoma, the pathology suggested Pagetoid spread of melanocytes and could erroneously support a diagnosis of melanoma.

Methods: Eleven cases of cutaneous ulcerations were immunohistochemically stained with SOX10 and histologically examined for size of ulceration, amount of dermal inflammation, and presence of significant upward movement of melanocytes.

Results: None of the 11 specimens showed significant upward movement of melanocytes. Ulcerations ranged in size from 1 to 4 mm, with 1/11 presenting with severe dermal inflammation, 4/11 with moderate dermal inflammation, and 5/11 with mild dermal inflammation.

Conclusions: Our results suggest the initial case demonstrating SOX10 positive cells in the upper layers may have been an aberrant finding. There was no evidence suggesting SOX10 positivity in the upper layers of the epidermis is expected in cutaneous ulcerations.

Systemic Mastocytosis: A Cutaneous Presentation

Dianna Chormanski, MD,* Casey Bowen, MD,† and Kevin Krauland, MD‡

*Capt, USAF, Pathology Resident, Brooke Army Medical Center, Fort Sam Houston, TX; †Maj, USAF, Chief of Dermatology, Ehrling Bergquist Clinic, Offutt AFB, NE; and ‡Maj, USAF, Anatomic, Clinical, and Dermatopathology, Brooke Army Medical Center, Fort Sam Houston, TX.

An otherwise healthy adult female presented to the dermatology clinic with a widespread rash on her proximal extremities and lateral trunk composed of partially confluent tan macules with blanchable erythema in a reticular pattern. She reported the rash became red with exercise. Biopsy showed numerous mast cells in the superficial dermis with spindled and usual morphology. The mast cells were highlighted with CD117 and tryptase. These findings were consistent with a diagnosis of mastocytosis and follow up bone marrow biopsy showed marrow involvement supporting a diagnosis of systemic mastocytosis. Mastocytosis is a broad term which refers to disorders with mast cell hyperplasia. It is subdivided into cutaneous and systemic disease. Systemic disease often presents with cutaneous involvement with subsequent bone marrow involvement identified. This case demonstrates an interesting clinical presentation of systemic mastocytosis and is presented with high quality photomicrographs of skin and bone marrow with immunostains.

Infantile Fibrosarcoma: A Case Report

Shiva Jabbarim, MD, Behzad Salari, MD, Louis P. Dehner, MD, and Mai He, MD, PhD

Department of Pathology & Immunology, Washington University in St. Louis.

Infantile fibrosarcoma is a rare soft tissue tumor that presents during first year of life. It has a characteristic translocation t(12; 15)(p13; q25), with focus of ETV6-NTRK3. It can be easily misdiagnosed as a hemangioma with its highly vascularized appearance. A case of a 3 month old full-term boy with rapidly increasing size mass on his left forearm, treated conservatively with antibiotic with minimal improvement. Upon follow-up, revealed a mass in the radial aspect of the left forearm on MRI. A biopsy was performed that showed a dense dermal lymphohistiocytic infiltrate. Immunohistochemical studies demonstrated immunoreactivity of the tumor cells for vimentin, CD99, WT-1, INI-1, CD43, and CD45. There was no aberrant expression of T-cell markers. They were negative for many other immunostains including S-100, pankeratin, EMA, desmin and myogenin to name a few. Fluorescence in situ hybridization (FISH) was positive for ETV6 (12P 13.2) rearrangement, confirming the diagnosis of congenital infantile fibrosarcoma. The patient underwent wide excision of his mass and 16 months following excision, he remains free of recurrence.

Bullous Pemphigoid With Cutaneous Crohn's Disease

Caryn Cobb, BA, Joseph Caravaglio, MD, Abrar Qureshi, MD, and Leslie Robinson-Bostom, MD

The Warren Alpert Medical School of Brown University, Providence, RI.

Cutaneous Crohn's disease is an extraintestinal manifestation of Crohn's disease characterized by nonspecific plaques or nodules. Bullous pemphigoid, a subepidermal autoimmune blistering disorder, has been observed in the setting of inflammatory bowel disease. We present a 58-year-old woman with a history of Crohn's disease who presented with recurrent bullae affecting the abdomen, thighs and buttocks of one year's duration. At the time of presentation, the patient was not on immunosuppressive therapies but had been previously treated with infliximab and azathioprine for Crohn's disease which were discontinued eight years before blistering commenced. Punch biopsy of lesional skin showed a sub-epidermal blister with eosinophils. Sarcoidal and tuberculoid granulomas were present in the dermis below the sub-epidermal vesicle. Punch biopsy of peri-lesional skin for direct immunofluorescence revealed linear 2+ IgG and 3+ C3 along the basement membrane. These findings support the diagnosis of bullous pemphigoid with concomitant cutaneous Crohn's disease. This case is believed to be the first report of cutaneous Crohn's disease and bullous pemphigoid manifesting concurrently on histologic examination.

Cutaneous Crohn's Disease Presenting as Granulomatous Panniculitis With Caseation Necrosis

Caryn Cobb, BA, Christopher Elco, MD, PhD, Gladys Telang, MD, Leslie Robinson-Bostom, MD, and Lionel Bercovitch, MD

The Warren Alpert Medical School of Brown University, Providence, RI.

Cutaneous (metastatic) Crohn's disease clinically presents with plaques, nodules, erosions, ulcerations and abscesses. Histopatholology characteristically shows noncaseating granulomas. A 15-year-old female developed a nodule on her left lower extremity that progressed to a painful ulceration. After treatment with multiple courses of antibiotics and debridement of the lesion, it healed over 6 months. She subsequently developed indurated pink nodules with ulceration on her left pretibial region that did not resolve with oral and intravenous antibiotics. Initial biopsy of the pretibial area showed non-necrotizing granulomatous panniculitis. Repeat biopsy showed subcutaneous granulomas with caseating necrosis. Acid-fast, periodic acid-Schiff and Gram stains were negative for microorganisms. She was diagnosed 14 months after initial presentation with intestinal Crohn's disease. Cutaneous Crohn's disease may predate gastrointestinal symptoms and should be included in the histologic differential diagnosis of granulomatous dermatitis with or without caseation necrosis. This case is unique in its presentation with granulomatous panniculitis with caseation necrosis.

Giant Spiradenocylindroma of the Scalp Clinically Mimicking a Vascular Tumor

Yahya Daneshbod, MD, Jason Kissell, DO, and Justin Kerstetter, MD

Department of Pathology and Laboratory Medicine, Loma Linda University Medical Center, Loma Linda, CA.

A 68-year-old female presented to the emergency department with recent rapid growth of a hemorrhagic mass on her forehead, chronic fatigue and hemoglobin of 5 g/dl. She states that the mass has been present for four years and initially began as a small, clear cyst-like structure that has been progressively growing (Panel A1-3). Computed tomography (CT) scan without contrast showed a 6.4 × 6.9 × 9.1 cm soft tissue mass along the right frontal scalp, demonstrating marked heterogenous enhancement (Panel A4). A CT scan with contrast revealed that the mass may represent a neoplasm of vascular origin, such as a hemangioma, hemangiosarcoma or a venous malformation (Panel A6-7). A biopsy of the lesion caused hemorrhaging of about 250 cc, necessitating a blood transfusion. Immunohistochemical studies performed on the biopsy were positive for pan-cytokeratin, Cam5.2 and S100, while CK5/6 and EMA were only found to be positive in scattered basal cells and ductal cells respectively. The lesion was negative for Ber-EP4 and p63. Histologic impression of the biopsy was for a benign adnexal neoplasm with ductal differentiation, favoring eccrine spiradenoma. Later complete surgical excision of the mass revealed a variegated tan-pink, smooth and red-yellow, semi-firm, subepidermal tumor with friable central areas (Panel A8). Histologically it was still thought to be a benign eccrine neoplasm, specifically a spiradenocylindroma (Panel A9). Spiradenomas and dermal cylindromas are cutaneous benign neoplasms occurring as solitary or multiple tumors arising from eccrine glands. They have a predilection for head and neck areas and can arise within the same lesion or as separate lesions. They can be found as a component of Brooke-Spiegler syndrome. Clinically, radiologically and pathologically adnexal skin tumors may mimick more common tumors of soft tissue, salivary gland or skin.

An Unusual Presentation of Lupus Vulgaris Misdiagnosed as Psoriasis

Farhad Handjani,* Parastoo Khairandish,† Mojgan Akbarzadeh Jahromi,‡ and Yahya Daneshbod, MD§

*Molecular Dermatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran; †Sal Medical Complex, Shiraz, Iran; ‡Department of Pathology, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran; and §Department of Pathology and Laboratory Medicine, Loma Linda University Medical Center, Loma Linda, CA.

We report a case of lupus vulgaris (LV) on the left upper extremity and left axillary area of a 17-year-old female. Her skin lesions started when she was five years old and she was misdiagnosed as having psoriasis for years before she referred to our dermatology department for a second-opinion evaluation. On clinical examination, she had two large lesions on the left upper extremity and left axillary area with central atrophic changes and a dry erythematous scaly border (Figures 1 & 2). The lesions had increased in size with time and she was diagnosed as having psoriasis. She received many topical steroid formulations with no response. At our clinic we requested some lab tests and a skin biopsy. Laboratory resulted showed a high ESR as well as monocytosis. Her PPD test was strongly positive (25 mm) and her skin biopsy showed chronic granulomatous inflammation with a negative PAS stain. PCR for mycobacterium tuberculosis and leishmaniasis was negative. Since detecting acid-fast bacilli is very rare in cases with lupus vulgaris, taking into account her clinical picture and course as well as her positive TB skin test and laboratory results in the setting of a chronic granuloma, we started anti-TB therapy and the patient is being followed. Our experience is discussed (Handjani F, Delir S, Sodaifi M, Kumar PV. Lupus vulgaris following bacille Calmette-Guérin vaccination. Br J Dermatol. 2001 Feb;144(2):444-5.).

A Case of Cutaneous Peripheral T-Cell Lymphoma With Novel Findings for Targeted Treatment

Carlo De-la-Sancha, Simon Warren, and Mehdi Nassiri

Indiana University School of Medicine.

A 70-year-old man with a history of T-cell-prolymphocytic leukemia, who developed donor-derived NK-lymphoproliferative disorder post-bone marrow transplant presented with a 4cm abdominal plaque concerning for recurrence of lymphoproliferative disorder. Biopsy revealed a dermal infiltrate of medium-sized atypical lymphocytes positive for CD2, CD3, CD5 and CD8 with aberrant CD20 expression. TCR clonality studies showed different clone compared to his two previous diagnoses. Six months later, he progressed with multiple skin lesions and lymphadenopathies with similar immunophenotype and clone. He received localized radiation therapy, however within three months he developed multiple additional cutaneous lesions. Since tumor cells were CD20 positive, rituximab was attempted with unsuccessful response. NGS showed MTOR mutation and he received MTOR inhibitor TAK-228, which had a dramatic effect for a short period. The patient developed multiorgan failure and died within six months. Primacy cutaneous peripheral T-cell lymphoma is a progressive, fatal dermatologic disease that needs to be distinguished from other cutaneous T-cell lymphomas due to its prognostic and therapeutic implications. In addition, mTOR mutation, which is uncommon in T-cell lymphoma, may play a therapeutic role.

Neosporin®-Induced Allergic Contact Dermatitis With Spongiforn Pustules, An Unusual Presentation

Carlo De la Sancha,* and Terrence Katona†

*Indiana University School of Medicine; and †Roudebush VA Medical Center.

Neosporin® is a widely used topical antibiotic preparation with active ingredients of neomycin, bacitracin, and polymyxin. Neomycin is known to cause allergic contact dermatitis but the presence of spongiform pustules would be unusual in this setting. We report a case of a 49 year-old man with history of melanoma who presented with a 1-month duration erythematous, vascular appearing papule on his chest with surrounding erythema. The patient had been using Neosporin ointment in effort to treat his primary lesion. Skin shave biopsy demonstrated an eroded pyogenic granuloma with adjacent spongiotic dermatitis. The adjacent intact epidermis showed eosinophilic spongiosis and areas of spongiform pustule formation. A PAS stain was negative for pathogenic fungal organisms. We believe that our case is unusual based on the presence of spongiform pustules in an allergic contact dermatitis, a feature not typically seen in this entity. The possibility that nearby erosion contributed to this morphology (impetiginization) can be considered. Alternatively, these findings may represent pustular variant of contact dermatitis.

Primary Parotid Tumor Thrombosis: Immunohistologic Features and Awareness of Metastatic Potential

Antonio Dekhou, BS,* Rafey Rehman, BS,* Jacob Parzen, MD,† Thomas Quinn MD,† and Rohan Deraniyagala, MD†

*Oakland University William Beaumont School of Medicine, Rochester, MI; †Department of Radiation-Oncology, William Beaumont Hospital, Royal Oak, MI.

Introduction: Tumor thrombosis is a poor prognostic feature and is exceptionally rare in salivary gland malignancies.

Methods: We identified a case of primary parotid epithelial-myoepithelial carcinoma (EMC) with tumor thrombosis.

Results: An 82-year old male presented with a complaint of a right facial mass. Imaging demonstrated a mass of the right parotid gland with attenuation of the right external jugular vein (EJV). The patient underwent right parotidectomy and selective neck dissection. Tumor thrombosis was found intraoperatively within the EJV. Final pathology demonstrated a poorly differentiated EMC. The tumor was positive for CK5/6, p16, p40, SOX10, smooth muscle actin, myosin, and synaptophysin, but negative for INSM1, NUT, S100, ERG, and uroplakin. Adjuvant radiation therapy was administered. Three months later, imaging revealed numerous bilateral pulmonary nodules with biopsy demonstrating poorly differentiated EMC without locoregional relapse.

Conclusions: Primary parotid tumor thrombosis is rare and carries a poor prognosis. The use of early systemic therapy should be investigated.

CK20+/CK7- Metastatic Breast Carcinoma to the Skin

Roman Drozdowski, Kristin Torre, and Michael Murphy

UConn Dermatology, Farmington, CT.

A 72-year-old women presented with a right chest mass. She was diagnosed with breast cancer (ductal carcinoma) 41 years prior, with metastatic disease (CK20+/CK7- immunophenotype) to non-cutaneous sites over recent years. Histopathology of skin biopsy showed intradermal infiltrating adenocarcinoma. By immunohistochemistry, tumor cells were reactive for Cam 5.2, ER, GATA3, and CK20; and negative for CK7, PR, CDX2, and Villin. The histopathologic and immunochemical features supported the diagnosis of metastatic breast carcinoma to the skin with variant CK20+/CK7- immunostaining. Up to 6%–8% of breast cancers express CK20+, with 1%-1.6% of cases showing a CK20+/CK7- immunoprofile, as in our case. CK20 expression has been reported to carry prognostic significance in breast cancer—associated with increased stage, metastases, and lower overall survival. Only one prior example of metastatic cutaneous CK20+/CK7- breast cancer has been described in the literature. For metastatic carcinomas, immunostaining for cytokeratin expression is used to confirm epithelial differentiation and determine primary tumor site (CK7 and CK20). Rarely aberrant immunophenotypes are identified. This report highlights the importance of correlating cytokeratin immunostaining with that of previously sampled tumor, if available.

Hyperpigmentation in a Transplant Patient: Not What We Expected

Danielle Fasciano, DO, David Ullman, MD, Stephanie Bevans, MD, Natalie Larsen, MD, Craig Elmets, MD, and Peter Pavlidakey, MD

Department of Dermatology, UAB, Birmingham, AL.

HPyV7-associated pruritic and dyskeratotic dermatosis (HPDD) is exceedingly rare. We present one such case in an immunosuppressed individual. A 58-year-old male with a history of cardiac transplant and extensive tinea corporis presented with a 5-month history of a papulosquamous rash characterized by hyperpigmented papules and plaques with minimal scale along the extremities and back. The differential diagnosis included worsening tinea corporis or possible graft versus host disease. Treatment with terbinafine showed no improvement with continued spreading of lesions. Biopsy revealed an expanded stratum corneum and keratinocytes with eosinophilic viral inclusions characteristic of a “peacock plumage pattern.” GMS was negative for fungal organisms. Staining for human polyomavirus 7 was positive in the stratum corneum and epidermis. While rare, HPDD's unique “peacock plumage pattern” should trigger an appropriate workup including confirmatory immunohistochemical studies. This entity has unique treatments necessitating establishing the correct diagnosis. This case highlights the difficulty in establishing this diagnosis especially in the context of other more common entities such as tinea corporis.

Angioimmunoblastic T Cell Lymphoma: An Aggressive Peripheral T Cell Lymphoma

Danielle Fasciano, DO, David Ullman, MD, Alison Burkett, MD, Harris Reynolds, MD, Craig Elmets, MD, and Peter Pavlidakey, MD

Angioimmunoblastic T cell lymphoma (AITL) is an aggressive neoplasm of mature T-follicular helper cells. Extranodal sites are frequently involved at presentation. We present a case with skin involvement at the time of diagnosis. An 80-year-old male presented with a painful, pruritic rash. Physical examination revealed diffuse erythema and scale affecting >80% of his body surface area (BSA), along with fissuring of the palms and soles. Histologic examination showed a dermal infiltrate of small lymphocytes with limited involvement of the epidermis. The lymphoid infiltrate consisted predominantly of CD3+/CD4+/CD8- T cells that showed partial expression of CD10 and partial loss of CD2 and CD7. BCL-6, CD56, CD30, and CD1a were negative. Concurrent flow cytometry demonstrated an aberrant CD4/CD279+ T cell population. The IHC and flow cytometry findings were consistent with skin involvement by AITL. The patient underwent port placement and subsequent chemotherapy. This case emphasizes the aggressive nature of AITL. There is frequently extranodal involvement at the time of diagnosis; therefore, prompt diagnosis and treatment are essential.

SOX2 Upregulation in Actinic Keratoses Indicate Evolution to Invasive Squamous Cell Carcinoma and Positively Correlate With the Basal Growth Pattern of Atypical Keratinocytes (PRO I-III)

Caterina Ferreli,* Luca Pilloni,† Elisa Robustelli Test,* Licia Vultaggio,* Laura Casula,‡ and *Franco Rongioletti

*Section of Dermatology, †Section of Pathology, ‡Section of Statistics, Department of Medical Sciences and Public Health, University of Cagliari, Italy.

In recent times there has been some debate as to whether the classic histopathological classification of AK (AK I-III) is of any utility in the identification of the probability of progression to invasive SCC (iSCC). Lately a more appropriate new classification has been proposed, (PRO I-III) based on basal growth patterns of atypical keratinocytes. This classification seems to be more reliable in assessing the progression form AK to iSCC and do not correlate with the classic AK I-III classification (1,2). The transcription factor Sox2 has been widely reported to be involved in human carcinogenesis and several malignancies, including SCCs. In the normal human skin Sox2 is not expressed but is expressed in cutaneous iSCC(3). The purpose of the present study is to assess, by immunohistochemistry, the expression of Sox2 in patients with AK and to evaluate the expression in the different histological subtypes of AK according with the PRO I-III classifications in order to better understand the stepwise progression of AKs into iSCC. Fifty-seven sections from skin biopsies of 56 patients were first observed and catalogued according with the PRO I-III classification giving a descriptive analysis of the expression of the anti-SOX2. Of the 57 lesions included in the study, 18% (10) were histologically classified as crowding (PRO I), 35% (20) as budding (PRO II) and 47% (27) as papillary sprouting (PRO III). Overall, 61% (35) of the 57 AK showed weak to moderate and strong nuclear expression of Sox2. The pattern of expression was categorized focal 83%(29) or diffuse 17%(6); the positivity was either on basal 57%(20) or spinous 14%(5) layers of the epidermis, or on both basal and spinous 20% (7). Regarding the hypothesized difference in the expression of Sox2 in the different grades of AK, we observed an exponential raise of Sox2 expression consensual with the increased basal growth patterns of atypical keratinocytes PRO I-III (P = 0.023).

Conclusions: The results of our study improve our understanding of the pathogenesis of SCC developing from AK suggesting that SOX2 may be involved in later events of carcinogenesis, and not in the early progression. They also support the PRO classification of AK as indicative of AK progression into iSCC. Additionally, our findings indicate that the positivity for SOX2 expression in the spinous and basal layers may be a prognostic factor for tumor progression of AK.

Dermatofibrosarcoma Protuberans With Fibrosarcomatous Transformation Arising at the Site of Breast Implant

Koorosh Haghayeghi,* Joseph A Dicomo,† David Edmonson,† and Natalie Banet*

Departments of *Pathology and †General Surgery. Brown University, Rhode Island Hospital/Women and Infants Hospital. Providence, RI.

Fibrosarcomatous dermatofibrosarcoma protuberans is a rare variant of dermatofibrosarcoma protuberans (DFSP) with increased risk of recurrence and metastasis. Herein, we report the first case of DFSP with fibrosarcomatous transformation arising at the site of breast implant. The patient is 33-year-old woman with two year history of gradually enlarging medial breast mass arising adjacent to breast implant. This mass was radiologically suggestive of intradermal sebaceous cyst. Physical exam revealed a 5x4 cm erythematous mass. Excisional biopsy showed deep dermally based proliferation of cells with elongated spindle-shaped nuclei arranged in storiform pattern with focal areas of increased atypia and mitoses consistent with early fibrosarcomatous transformation. The tumor cells were diffusely positive for CD34, and negative for caldesmon, CD31, S-100 and desmin. Surgical excision was limited due to adjacent implant. Patient is to undergo radical re-resection with removal of breast implant for complete tumor clearance. Further study is warranted to examine possible relation between implants and DFSP.

Misdiagnosed Majocchi Granuloma in Immunocompromised Men

Mina Haghighiabyaneh,* and Shawna K. Langley†

*Department of Pathology, Loma Linda University School of Medicine, CA; and †Department of Dermatology, VA Loma Linda Healthcare System, CA.

Majocchi's granuloma is a very rare condition in which a dermatophyte invades the deeper layers of the dermis and subcutaneous tissue and can often be misidentified and treated as Prurigo Nodularis. Clinical presentation varies according to the response of the host. Immunocompetent patients may develop erythematous papules, perifollicular nodules, or even pustules. Immunocompromised hosts may also present subcutaneous nodules or abscesses. Seldom, systemic dissemination may occur. The aim of this study is to describe the case of a immunocompromised patient who developed severe rashes on his shoulder and back for one year that have been diagnosed as Prurigo Nodularis but were not improving with empirical steroid treatment. A combination of physical exam and KOH was used to identify the disease. Patient had satisfactory relief after treatment with terbinafine.

An Indolent Cutaneous Gamma/Delta T-Cell Lymphoma With Prominent Epidermotropic Pattern in Three Years Old Patient

Y. Hambaroush, C. Sorge, R. Arora, and D. Piecoro

Primary cutaneous gamma-delta T-cell lymphoma (GDTCL) is a rare aggressive disease that typically involves the dermis and subcutis in young adults with male predilection. The lymphoma cells are diffusely positive for CD3 and T-cell receptor. TCR-γ. We hereby present a rare case of GDTCL with epidermotropic pattern in a pediatric patient with indolent course. Three years old male presented to the dermatology clinic with a large raised cutaneous flaky satellite lesions on left arm. The patient was otherwise healthy with unremarkable family history. The skin biopsy revealed a patchy perivascular and periadnexal dermal lymphoid infiltrate in the superficial and deep dermis. The infiltrate showed marked epidermotropism, with occasional mitotic figures and scattered apoptotic cells. The atypical lymphoid cells were positive for CD3, CD56 with partial loss of CD7 and double negative for CD4 and CD8. They stained positive for TCR-γ and negative for CD5, BF1, perforin, granzyme, CD117, TdT and EBER. The overall features were consistent with Primary cutaneous GDTCL with significant epidermtropism and Pautrier microabscesses. Close observation was opted as some of the skin lesions resolved spontaniously over the course of five months, since this does not appear to be as aggressive as suspected based on adult literature. Primary cutaneous GDTCL is associated with significantly decreased survival, however the GDTCL with predominantly epidermotropic pattern are clinicopathologically distinct from classic primary cutaneous GDTCL, and has shown a better prognosis and median survival according to Merrill et al.

CD138 Staining in Neurothekeoma

Madison Hannay, DO and Jessica Forcucci, MD

Medical University of South Carolina, Charleston, SC.

Neurothekeomas are benign dermal tumors with a broad differential diagnosis that can mimic soft tissue tumors and recur if incompletely excised. We describe CD138 staining of neurothekeomas, as additional immunophenotypic information may aid in diagnosis and differentiation from other entities.

Methods: Following unexpected CD138 positivity in one neurothekeoma (index case), a retrospective search of departmental archive material was conducted. Tweleve cases were obtained. Unstained, de-identified sections were acquired from archival paraffin blocks and were stained with CD138. The staining pattern was assigned a strength (as compared to internal epidermal control) of blush, weak, moderate, or strong, and distribution of rare (<5%), minority (5-50%), and diffuse (>50%).

Results: Eight of 12 cases demonstrated some degree of positivity for CD138. One demonstrated strong, diffuse staining (index case). Three exhibited moderate, diffuse staining. Four were negative. The remaining cases demonstrated variable weak or patchy staining.

Conclusions: While not all cases were positive, the majority showed some degree of CD138 expression. The significance of this finding and reproducibility with other antibody clones is unknown. Knowledge of this positivity may prove useful in avoiding potential diagnostic pitfalls.

Birt-Hogg-Dubé Syndrome Presenting as Multiple Fibrous Papules

Christian Hopkins,* and Jacqueline M. Junkins-Hopkins†

*University of Pennsylvania, Philadelphia, PA; and †Geisinger Medical Center, Danville, PA.

Birt-Hogg-Dubé syndrome (BHDS) is caused by a mutation in the folliculin gene and is clinically characterized by multiple facial papules that include fibrofolliculomas, trichodiscomas and acrochordons. BHDS is additionally associated with multiple lung cysts, an increased risk of spontaneous pneumothorax, and renal tumors. A 61-year-old male with a history of numerous facial papules previously diagnosed as fibrous papules presented with additional papules. A diagnosis of BHDS was suspected and a biopsy was obtained revealing a dome shaped neoplasm with a fibrous stroma, sparsely scattered dendritic cells, and perifollicular fibrosis. Review of prior biopsies showed similar findings. The neoplasm was diagnosed as a benign mesenchymal neoplasm consistent with BHDS. The patient was referred to genetic counseling, where a family history of pneumothorax and kidney disease was identified. Subsequent genetic testing uncovered a mutation in the folliculin gene, confirming BHDS. Until recently, fibrous papules have not been included in the proposed criteria for BHDS, and it is beneficial to recognize this rarely reported presentation of the disease such that adequate tumor screening can be pursued.

New Variant of Fibrous Papule Containing Ganglion-Like Cells: Case Report and Literature Review

Aamir Hussain, MD, MAPP,* Amor Khachemoune MD, FAAD, FACMS,† and Masoud Asgari MD‡

*MedStar Washington Hospital Center, Dermatology Residency, Washington, DC; †Veterans Affairs Medical Center and SUNY Downstate, Department of Dermatology, Brooklyn, NY; and ‡Yosemete Pathology Medical Group, San Ramon Regional Medical Center, Department of Pathology and Laboratory Medicine, San Ramon, CA.

Background: Fibrous papules are common, benign lesions that appear on the face among middle-aged adults. Although several histologic variants have been described including epithelioid-cell, clear-cell and granular-cell types, ganglion-cell type is not generally seen.

Methods: We report the unique case of fibrous papule with ganglion-like cells, describe morphologic features of this variant and emphasize its similarities with other soft-tissue neoplasms containing pleomorphic cells. Database search of PubMed, Scopus, and Google Scholar was conducted to review other reports of these rare neoplasms.

Results: We found only one other published report of fibrous papules containing ganglion-like cells. This variant has not been well-elaborated and should be considered a distinct subtype.

Conclusions: The differential diagnosis of cutaneous lesions with ganglion-like cells should be expanded to include fibrous tumors in order to avoid misdiagnosing malignant processes that may lead to unnecessary procedures.

First Case Report of Hemodialysis Catheter-Induced Subcutaneous Hair Shaft Granuloma

Christopher P. Julien, MD, Mitul B. Modi, MD, and Michael A. Husson, MD

Department of Pathology and Laboratory Medicine, Pennsylvania Hospital of the University of Pennsylvania Health System, Philadelphia, PA.

Case Description: A 37-year-old female with a history of end stage renal disease presented with a 1 cm, hard, mobile, subcutaneous nodule located above the midline of the left clavicle. Her initial hemodialysis catheter was placed at this site in 2014, the same year that the nodule was first noted. The lesion has been stable in size and asymptomatic since then. An FNA was non-diagnostic and revealed multiple multinucleated giant cells, prompting excision. On H&E, the lesion is a fibrous nodule consisting of numerous hair shafts with an associated giant cell reaction. Extensive hemosiderin deposition is present. A pankeratin stain was negative and did not reveal any other features of a dermoid cyst (adnexa, squamous epithelium). No cyst lining or sinus tract is present. We postulate that the nodule represents the residual elements of a dermoid cyst, although the possibility of traumatically introduced patient hair at the time of catheter placement cannot be excluded.

A Rare Case of Oncocytic Hidradenoma With Epidermal Connection

Karimi S. S.,* O'Brien R.,† Tsoukas M.M.,† and Braniecki M.*

Departments of *Pathology and †Dermatology University of Illinois at Chicago, IL.

Hidradenoma is a sweat gland adnexal neoplasm that can display numerous varieties including clear cell, mucinous squamoid, polyhedral eosinophilic, transitional and oncocytic cell types. Cutaneous oncocytic hidradenoma is a rare subtype of hidradenoma characterized by granular eosinophilic cytoplasm due to the abundant presence of mitochondria. Hidradenomas typically show a solitary dermal nodular lesion that usually do not exhibit epidermal connections. Herein, we report a rare case of an oncocytic hidradenoma with epidermal connection. Our patient is a 44-year-old female who presented with a 0.6 × 0.6cm skin nodule on her left nasolabial fold that was first noticed 6-months ago. Microscopic examination of the excisional biopsy showed a well-demarcated, dermal nodular lesion, composed of cohesive glandular epithelial cells containing abundant eosinophilic cytoplasm with direct connection to the overlying epidermis. Immunohistochemical studies demonstrated tumor immunopositvity for EMA, Brst-2, and CK7. PAS showed cytoplasmic uptake consistent with glycogen content. PTAH staining highlighted the cytoplasmic granules. In conclusion, we share this case of a rare oncocytic variant of a hidradenoma that also showed epidermal connection.

A Case of Post-Irradiation Extragenital Lichen Sclerosus ET Atrophicus With Prominent Elastophagocytosis

Esther Kim, MD and Oluwakemi Onajin, MD

Section of Dermatology, University of Chicago, Chicago, IL.

A 56-year-old female with a history of invasive ductal carcinoma of the left breast presented with a lesion on the left axilla. Two years prior, she underwent neoadjuvant chemotherapy, partial mastectomy with sentinel lymph node biopsy, and radiation therapy. Physical examination revealed an 8 × 3 cm oval, ivory-white, atrophic plaque with overlying telangiectasias on the left axilla. A biopsy demonstrated epidermal atrophy with papillary dermal hyalinization and edema, and underlying lymphocytic and granulomatous inflammation with elastophagocytosis. A Verhoeff-Van Gieson stain confirmed elastophagocytosis with decreased elastic fibers within the hyalinized areas. On immunohistochemical staining, CD68 highlighted the histiocytes and CK7 was negative for metastatic carcinoma. A diagnosis of post-irradiation lichen sclerosus et atrophicus (LS&A) was made and she was treated with potent topical corticosteroids. Post-irradiation LS&A is a rare side effect of radiation therapy. To our knowledge, only 6 cases have been reported to date and none demonstrated elastophagocytosis. We present this case of post-irradiation LS&A with elastophagocytosis to highlight a rare side effect of radiation therapy with a unique histopathological finding.

Hidradenocarcinoma of the Abdomen: A Call for Increased Awareness of This Tumor

Rafey Rehman, BS,* Muhammad Osto, BS,† Bryan Squires, MD,‡ Thomas J. Quinn, MD,‡ and Peyman Kabolizadeh, MD, PhD‡

*Oakland University William Beaumont School of Medicine, Rochester, MI; †Wayne State University School of Medicine, Detroit, MI; and ‡William Beaumont Hospital, Royal Oak, MI.

Introduction: Hidradenocarcinomas are rare malignant sweat gland tumors that typically arise in the head and neck area. To our knowledge, this is the only reported instance of hidradenocarcinoma of the abdominal wall and the first reported instance to present with symptomatic lesion after trauma.

Methods: A 72-year-old female presented with a left abdominal wall lesion, which she had first noticed after an injury to the area. Initially, the lesion remained stable in size, after which it became mildly pruritic, progressive in size, and expressive of a clear, non-odorous discharge. Imaging demonstrated a heterogeneous cystic density. Surgical pathology revealed a malignant dermal adnexal neoplasm composed of pleomorphic polygonal cells and focal intracytoplasmic lumina lined by eosinophilic cuticles, as well as areas of ductal differentiation, apocrine differentiation, and mucinous metaplasia. Surgical excision of the mass was performed, followed by adjuvant external beam radiotherapy (ERBT).

Results: The patient had no long-term toxicities or disease recurrence as of one-year post-surgery and six months post-ERBT.

Conclusions: Early diagnosis and treatment is essential to improving outcomes in patients with hidradenocarcinomas. Frequent follow-up is equally important, as these tumors have high recurrence rates.

Facial Blaschkitis Following 5-Fluorouracil

Jamison A. Harvey, MD, David L. Swanson, MD, Steven A. Nelson, MD, and David J. DiCaudo, MD

Department of Dermatology, Mayo Clinic, Scottsdale, AZ.

Introduction: Blaschkitis typically presents in adults with multiple, erythematous papules distributed along the lines of Blaschko. Histopathology frequently shows spongiotic dermatitis or a lichenoid pattern. It's controversial whether blaschkitis is a separate entity of adult lichen striatus.

Case Report: A 42-year-old woman presented with a rash on her forehead that started after treatment of 5-fluorouracil for a biopsy proven actinic keratosis at an outside institution. Subsequently, she developed a new rash that slowly elongated over five months. On exam, there were multiple pink macules coalescing into a linear patch on the right paramedian forehead extending from her scalp to her mid-forehead. Histopathology revealed a lichenoid reaction pattern with perivascular and perifollicular lymphocytic inflammation. She was treated with tacrolimus 0.1% twice daily.

Discussion: We report case of blaschkitis following treatment with 5-flourouracil that histopathology revealed a lichenoid reaction. Blaschkitis has previously been associated with trauma, hepatitis B vaccination, solarium sessions, pregnancy, oral contraceptives, but has not yet been reported following 5-fluorouracil. It's possible the blaschkitis occurred due to inflammation of 5-fluorouracil inducing local trauma.

Adnexal Neoplasm With Panfolliculoma Features Showing Prominent Pilomatricomal Differentiation

Chelsea Kramish, Cameran Nguyen, and John Metcalf

Medical University of South Carolina, Charleston, SC.

Panfolliculoma, first described by Ackerman et al in 1993, is a benign and rare adnexal neoplasm that recapitulates all components of a hair follicle. Through the years, other authors have reported additional cases of panfolliculoma and have tried to further subclassify this entity into three subtypes – superficial, nodular and cystic. Clinically, a 71-year-old male presented with a large skin mass on the left arm showing ulceration and erosion. On histologic section the lesional epidermis shows an attempt to differentiate toward both the upper (infundibulum, isthmus) and lower (stem, bulb and mesenchymal papilla) components of a hair follicle. Directly adjacent and underlying the epidermal process are dermal based nodular proliferations of ghost/shadow cells and rare matrical cells with focal dystrophic calcification. The surrounding stroma shows giant cell reaction, granulation tissue changes and fibrosis extending to the subcutaneous adipose tissue. This adnexal neoplasm is compatible with a panfolliculoma of the superficial subtype that has uniquely pronounced pilomatricomal differentiation.

Cutaneous CIC-DUX4 Sarcoma or Not?

Natalie Larsen,* Danielle Fasciano,* Thomas Winokur,* and Peter Pavlidakey†

*Department of Pathology University of Alabama at Birmingham; †Department of Dermatology University of Alabama at Birmingham.

A 31-year-old female presented to her dermatologist for burning pain associated with a lesion of the left flank. She believed it to be a skin tag that had been slowly enlarging over eight months. The punch biopsy revealed a small round cell tumor and, given the lack of history, an extensive panel was ordered and the cells were positive for both CD99 and DUX4. The patient was sent for staging and appropriate wide local excision. The excision had a large nodular mass extending from the dermis to the subcutaneous tissue. Undifferentiated small round cell sarcomas are considered to be a subgroup in the family of Ewing sarcomas. With new molecular studies, there is now a recognized group of “Ewing-like sarcomas” with characteristic histology, immunohistochemistry staining, and lack of the gene rearrangement seen in the Ewing family of tumors. One such tumor harbors a CIC-DUX4 rearrangement. This rare tumor most often arises in soft tissue and has aggressive behavior.

A Superficial Variant of Solitary Idiopathic B/T Pseudolymphoma: Should the Term be Completely Abandoned?

Aofei Li, MD and Viktoryia Kazlouskaya, MD, PhD

UPMC, Pittsburgh, PA.

The term “superficial solitary idiopathic B/T pseudolymphoma” was suggested by Cerroni but later questioned and suggested to be reclassified into lichenoid lymphomatoid keratosis (LLK). Herein we present a case with unusual superficial mixed lymphomatoid infiltrate. A 59-year-old male had a 7 cm, asymptomatic, oval, non-scaly, erythematous patch on the left upper arm stable for 1 year. Biopsy revealed dense band-like lymphoplasmacytic infiltrate without atypia. The epidermis had focal spongiosis with lymphocyte exocytosis. The infiltrate was mixed with B/T lymphocytic populations. The B-cells were CD20+ with polyclonal light chains. The T-cells were diffusely positive for CD2, CD3, CD5, CD7, and PD-1. Ki-67 index was 1%. CD30, CD8 and CD123 highlighted scattered cells. TCR rearrangement test was inconclusive. We considered lymphomatoid contact dermatitis, small/medium CD4+ lymphoproliferative disorder, CLL, lupus erythematosus, and MF; however, none of these entities ideally fitted our case. LLK was also considered; however, clinically there was no adjacent solar lentigo or keratosis, and the lesion was large in diameter without scaling. Our case rather fitted the description of a superficial B/T mixed pseudolymphoma.

Degos Disease (DD) With Features of Lichen Sclerosus ET Atrophicus (LSA)

Aofei Li, MD and Viktoryia Kazlouskaya, MD, PhD

UPMC, Pittsburgh, PA.

The multisystem form of DD has poor prognosis. However, another form of purely cutaneous benign DD (BDD) exists and may be underdiagnosed. Fully developed BDD can mimic LSA. Herein we report a 33-year-old obese female with a cluster of 3 mm round, atrophic, white with rim of erythema, shiny papules on the right flank for 2 years, clinically considered BDD, LSA or scar. No genital lesions of LSA were seen. She had a history of recurrent miscarriages corrected with daily aspirin. Antiphospholipid antibodies and Factor V Leiden were negative. Biopsy revealed wedge-shaped dermal sclerosis with epidermal atrophy and prominent dermal mucin deposits. Superficial perivascular and deep peri-adnexal/perineural lymphocytic infiltrates were present. While BDD and LSA may present similarly, a small, extragenital, asymptomatic lesion supported BDD. Despite the histologic mimicry, deep infiltrates and mucin depositions favored BDD. Vascular thrombotic changes are often not evident in BDD. Although the patient may be free of systemic complications, it's still important to diagnose a BDD, as some may progress in the future. Our case exemplified the clinicopathological differential diagnosis between BDD and LSA.

Follicular Hybrid Cysts (Infundibular and Pilomatricoma) in Mosaic Tetrasomy 9P

Dan R. Lopez, MD, Cathy Massoud, MD, Dirk Elston, MD, and Lara Wine-Lee, MD, PhD

Medical University of South Carolina, Charleston, SC.

Cysts with infundibular and pilomatrical components are within the spectrum of follicular hybrid cysts. Multiple pilomatricomas have been associated with systemic conditions, including Gardner syndrome, and tetrasomy 9p. Hybrid cysts have not been previously described in mosaic tetrasomy 9p within the English literature. A 14 year old boy developed multiple indurated nodules on his right temple, neck and extremities. His past medical history included mosaic tetrasomy 9p syndrome (50% affected cells), attention-deficit/hyperactivity disorder, and oppositional defiant disorder. Each specimen consisted of a dermal cystic structure with components of infundibular follicular epithelium (with preserved granular layer), pilomatrical differentiation (shadow and hair matrix cells), with abrupt transitions, and calcification foci. Multiple pilomatricomas have been described in association with Gardner syndrome, myotonic dystrophy, MYH-associated polyposis, Turner syndrome, trisomy 9, tetrasomy 9p, and other congenital syndromes. Hybrid cysts with pilomatrical and infundibular differentiation have been reported in association with Gardner syndrome, and in nevus sebaceous. A constitutively active beta catenin gene (CTNNB1) in the Wnt pathway is a proposed etiologic mechanism.

Dowling-Degos Disease Presenting With Associated Epidermal Inclusion Cysts

Kathleen C. Marinelli BS,* Lisa M. Marinelli MD,† and Mark S. Lincoln, MD†

*Creighton University School of Medicine, Omaha, NE; and †San Antonio Military Medical Center, San Antonio, TX.

With less than fifty cases reported in the literature, Dowling-Degos disease (DDD) is a rare autosomal dominant condition characterized by hyperpigmentation in the intertriginous areas, which is acquired in the third or fourth decade of life. A 31-year-old male presented with a several year history of intermittent nodules on the cheeks and axilla, which had been previously determined to be epidermal inclusion cysts. On further examination, numerous small areas of hyperpigmentation were noted on the upper chest, shoulders, and back, some of which were associated with ice pick scarring. Biopsy of the hyperpigmented lesions revealed epidermal acanthosis with filiform downgrowth of the epidermis, basilar hyperpigmentation, and scattered pseudohorn cysts, without evidence of acantholysis. This was consistent with a diagnosis of DDD. DDD is a rare and disfiguring disorder that should be considered in patients with characteristic hyperpigmented lesions. Herein we present a case with associated epidermal inclusion cysts, substantiating suggestions from several prior reports that DDD and epidermal cysts may be etiologically related.

Comedonal Lupus—A Rare Entity and Potential Pitfall in Inflammatory Dermatopathology

David Myers, MD, SAUSHEC and Nathaniel Smith, MD, SAUSHEC

San Antonio, TX.

We present a case of a 35-year-old male who developed 4–6 mm asymptomatic papules on his central chest and upper back. The patient was returning approximately one month after intralesional steroid injection treatment for recently-diagnosed discoid lupus presenting as alopecia. Clinically these new papules did not resemble his prior skin lesions. The clinical differential included acne rosacea, sarcoidosis, folliculitis, and an atypical presentation of lupus. Histologic evaluation demonstrated plugged and dilated follicular infundibula with vacuolar alteration and surrounding chronic inflammation. A superficial and deep perivascular and periadnexal lymphocytic infiltrate was present with increased dermal mucin. These findings were consistent with “comedonal variant” of discoid lupus. Only a few reports of “comedonal variant” cutaneous lupus have been described, which can be mistaken for other diagnoses, such as acne—one of the most common dermatologic diseases made by dermatologists and primary care providers alike. As acne is not routinely biopsied prior to treatment, misidentification can lead to delay of proper treatment. This case demonstrates clinical and histopathologic features of comedonal variant of lupus—a rare and important entity to consider in the setting of a papular eruption which can be easily mistaken for other dermatologic entities.

Clear Cell Papulosis: A Rare Hypopigmented Pediatric Dermatosis

Janira M. Navarro-Sanchez, MD,* Michael Black, MD,* and Allyson Spence-Shishido MD†

Department of *Pathology and †Dermatology, Kaiser Permanente Moanalua, University of Hawaii, Honolulu, HI.

Clear cell papulosis is a benign childhood skin dermatosis, with characteristic clinical and histopathologic findings, most frequently seen in healthy children younger than 6 years old. There is a predisposition for Asian or Hispanic descent. Lesions have a predilection for the abdomen and suprapubic area. This anatomic distribution demonstrates that they follow the milk line. We report a case of a 6 year old male with hypochromic macular lesions since infancy, up to 0.5 cm, located in the right upper chest, right mid chest, abdomen and suprapubic area. Pathology slides show mild acanthosis with scattered large clear cells confined to the basal epidermis. The cells are larger than adjacent keratinocytes, without nuclear atypia, or features of malignancy. Immunohistochemical studies show positivity to PAS, CK7 and negativity to S100. Clear cell papulosis is an uncommon cause of hypopigmented dermatosis seen in pediatric population. Clinically, this entity can be confused with other pediatric hypopigmented dermatosis. Microscopically, this entity can be misdiagnosed as Paget's disease or a non diagnostic skin.

Traumatized Acral Nevus...Oh Yes, They Are A Ballerina

Eric Ollila, MD,* Mahtab Fakhari, MD,* David Ullman, MD,† India Mayo Hill, MD,† Carly Elston, MD,† and Peter Pavlidakey, MD†

Departments of *Pathology, and †Dermatology, University of Alabama at Birmingham.

A 15-year-old Caucasian female ballerina presented to clinic with a two-year history of an enlarging, brown-black lesion involving the proximal nail fold of the third toe. Given the “changing nature,” the lesion was biopsied and showed an atypical junctional proliferation of melanocytes. The common features of both acral nevi and traumatized nevi were present. However, given the subtotal nature of the biopsy the clinical concern was high, especially with an extensive procedure causing nail dystrophy. The lesion was favored to be an atypical junctional nevus, and a subsequent marginal excision was negative. Despite well-known findings of acral nevi and melanoma (irregular dendrites, small hyperchromatic melanocytes, confluent pigmented parakeratosis, etc), this case highlights the importance of a good clinician providing needed clinical history and that histologic findings can be concerning regardless of the age of the patient.

Two Cases of Atypical Fusion Spitz Tumors with Histologic and Molecular Characterization

Michelle Pitch, MD, Ramya Chockalingam, MD, and Eric Hossler, MD

Department of Dermatology, Geisinger Medical Center, Danville PA.

Background: Spitz neoplasms range from benign (spitz nevus) to malignant tumors (spitzoid melanoma). The term Atypical Spitz Tumor describes an intermediate category met with clinical and histologic uncertainty. Ongoing molecular characterization is an active area of research to better understand these lesions.

Cases: Case 1 is a 49 year old man with a lesion on the back, clinically suspicious for an atypical nevus. Biopsy revealed a filigree pattern of nesting, marked maturation, and prominent adnexal nesting. These features were suggestive of NTRK fusion Spitz tumor, with subsequent positivity on NTRK1 immunohistochemistry. FISH revealed low level whole 6 gains in less than 30% of cells. Case 2 is an 8 year old boy with a pink papule on the leg. Biopsy revealed a wavy fascicular pattern of spindled melanocytes consistent with ALK fusion Spitz tumor, and confirmatory strongly positive ALK staining on IHC.

Conclusions: Recent studies have identified characteristic morphologic features corresponding to specific fusions. Familiarity with the histologic patterns of these fusion Spitz tumors is crucial for recognition of these entities.

A Rare Case of Bullous Erythema Multiforme Associated with Varicella Zoster Virus Infection

Bartlomiej Radzik, MD,* Mohammed Hassan, MD,* Cameron Trodello, MD,† Maria Tsoukas, MD, PhD,† and Marylee Braniecki, MD*

*University of Illinois at Chicago Department of Pathology and †Department of Dermatology Chicago, IL.

Erythema multiforme (EM) is an acute, self-limited, polymorphous mucocutaneous eruption that is regarded as a type IV hypersensitivity reaction. EM can be recurrent and can be triggered on by multiple factors including food, drugs and infections. Varicella zoster virus (VZV) has been rarely been reported as a trigger for EM. We describe a 47-year-old incarcerated, male with a 4-day history of a vesicular rash, that started on the trunk and had spread to his limbs, hands and oral mucosa. Patient believed that he had chicken pox as a child. Laboratory testing was negative for syphilis, herpes simplex and HIV. Direct fluorescent antibody and immunohistochemistry for Herpes were also negative. Skin biopsy showed an intraepidermal blister with keratinocytic necrosis-associated with an interface dermatitis, but without evident herpetic viral cytopathic morphology. However, VZV DNA was detected by PCR. His skin rash dramatically improved within the first 24 hours with IV acyclovir therapy. This case demonstrates VZV-associated bullous EM proven only by PCR, raising attention to underreported cases of EM associated with VZV-reactivation.

A Rare Case of Infantile Bullous Pemphigoid

Francisca Reculé, MD,*,† Ariana Eginli, MD,‡ Angela Niehaus, MD,* Dr. Omar Sangüeza, MD,*,‡ and Christine Ahn, MD*,‡

*Department of Pathology, Wake Forest School of Medicine, Winston Salem, NC; †Dermatology Service, Department of Surgery Universidad del Desarrollo, Clínica Alemana, Santiago, Chile; ‡Department of Dermatology, Wake Forest School of Medicine, Winston Salem, NC.

A five-month-old female previously healthy infant presented to the emergency department with a sudden onset bullous eruption. Her parents reported a recent history of vaccinations. On examination, there was a generalized eruption of tense bullae on an erythematous background affecting the trunk, extremities, palms, and soles. The differential diagnosis included chronic bullous dermatosis of the childhood, epidermolysis bullosa, bullous mastocytosis, viral exanthem, bullous arthropod bite reaction, incontinentia pigmenti, and bullous pemphigoid. Laboratory values revealed a peripheral eosinophilia; tryptase levels were normal. A biopsy specimen with direct immunofluorence (DIF) was obtained, which showed spongiosis with subepidermal bullae and numerous eosinophils within the epidermis and papillary dermis. DIF revealed linear IgG and C3 deposition at the dermo-epidermal junction. The patient was started on oral prednisolone with excellent response. Bullous pemphigoid (BP) is a rare autoimmune blistering disorder characterized by circulating autoantibodies against components of the hemidesmosome (BPAg1/BP230 and BPAg2/BP180).1 Typically a disease of older adults, BP in infants is exceedingly rare, with only 81 cases reported to date.1,2,3 The mean age of presentation of infantile BP is 4.5 months and acral involvement is common.1-3 Compared to adults, infantile BP follows a benign course, with good response to treatment and low recurrence rates. Some authors have proposed an immune-mediated vaccine response, although causal relationship has not been established.4 IgM deposition has been reported at increased frequency in childhood BP,2 though this was not seen in our patient. This case illustrates a classic presentation of a rare entity in infants; BP should always be considered in the differential of a bullous eruption, regardless the age.

Sclerotic Fibroma and PTEN Immunohistochemistry

Kayla J. Riswold, MD, Tammie C. Ferringer, MD, and Jacqueline M. Junkins-Hopkins, MD

Departments of Dermatology and Dermatopathology, Geisinger Medical Center, Danville, PA.

Background: Cowden syndrome is an autosomal dominant disorder with characteristic mucocutaneous lesions (trichilemmomas, sclerotic fibromas) and increased risk of internal malignancies caused by PTEN mutations. Histologically, sclerotic fibromas appear as well-circumscribed hypocellular dermal nodules of sclerotic collagen arranged as short stacks. Previous small studies have shown that loss of PTEN immunohistochemical (IHC) staining in trichilemmomas is a sensitive but less specific marker of Cowden syndrome with a similar positive predictive value as IHC evaluation for microsatellite instability in Muir Torre syndrome. PTEN expression has not been evaluated in sclerotic fibromas.

Case Description: We present a patient with a known germline PTEN mutation and multiple trichilemmomas and sclerotic fibromas. PTEN IHC expression was retained in both of his sclerotic fibromas while there was loss in 2 of 3 of his examined trichilemmomas.

Conclusions: Diagnosing Cowden syndrome is critical due to the increased risk of malignancy. PTEN IHC staining in sclerotic fibromas may not be a reliable marker of a patient's risk for a PTEN germline mutation but evaluation in additional patients is needed.

Papular Acantholytic Dyskeratosis as Presenting Sign of Hailey-Hailey Disease

Alexandra Ritter, John Metcalf, Dirk Elston, and Leah Swanson

MUSC, Charleston, SC.

Hailey-Hailey Disease (HHD) is a rare blistering disorder characterized by vesicles and macerated skin in intertriginous areas. While initially considered a separate disease, recent literature suggests papular acantholytic dyskeratosis (PAD) of the vulva, presenting with asymptomatic papules in the groin, is a localized variant of HHD with both diseases caused by ATP2C1 gene mutations. A 31-year-old woman with no relevant family history presented with a painful groin rash recently diagnosed as PAD. Examination was significant for eroded whitish verrucous papules across the vulva and perineum. Histopathology of biopsy revealed multilevel epidermal acantholysis, mild dyskeratosis, and focal viral cytopathic effect. Laboratory studies showed HSV-1 and Enterococcus faecalis superinfection. The patient initially responded to antimicrobial treatment but soon had recurrence of severe pain and itching and developed similar symptoms beneath the breasts. Follow up examination revealed macerated and eroded plaques in the inframammary creases. Histologic features of inframammary biopsy showed full thickness epidermal acantholysis, consistent with HHD. Dermatologists and dermatopathologists should be aware of the spectrum of presentation of HHD and closely follow and treat PAD patients similarly to those with HHD.

Iatrogenic Cutaneous Nodular Amyloidosis Due to a Novel Injectable Small Peptide

Margaret Wat, MD, PhD,* George Reilly, MD,† and Rosalie Elenitsas, MD*

*Dermatopathology, University of Pennsylvania, Philadelphia, PA; and †Warren, NJ.

A 38-year-old female with polycystic ovarian syndrome presented with a movable, non-tender, 1.5-inch, subcutaneous right hip nodule of several months' duration. Excisional biopsy revealed eosinophilic amorphous material, with many multinucleated giant cells and a mild lymphocytic inflammatory infiltrate. Plasma cells were absent. Congo Red staining highlighted the amorphous material, which exhibited apple green birefringence. Further history revealed she had been injecting liraglutide, a small peptide analog of glucagon-like peptide-1 (GLP-1), to that area for ten years to treat insulin resistance. She did not have a history of hematopoietic dyscrasias, although her brother had Hodgkin lymphoma. Complete metabolic panel and complete blood count were largely normal. Together, these findings are consistent with liraglutide-associated nodular amyloidosis, with only one other case previously reported. To date, insulin and enfuvirtide have been the only other small peptides demonstrated to cause iatrogenic secondary cutaneous amyloidosis. With the increase in small peptide injectable medications, our case illustrates the importance of recognizing these as possible causes, to avoid erroneously attributing the skin lesions to primary systemic AL amyloidosis.

Enlarging Scalp Nodule and Lymphadenopathy in A 17-Year-Old Female

K. Wade Foster,* Kayo Robinson, BS,† Eleanor Tung-Hahn,‡ George Gibbons, MD,§ C. Wayne Cruse, MD,¶ Jessica Wishnew, MD,ǁ Rebecca Tung, MD,** Wendy Kim, DO,† and Kumaran Mudaliar, MD††

*Department of Biology, Brigham Young University, Provo, UT; †Division of Dermatology, Loyola University Chicago Stritch School of Medicine, Maywood, IL; ‡Department of Biology, Siena College, Loudonville, NY; and §Dermpath Diagnostics, Tampa, FL; ¶Cutaneous Oncology Program, Moffitt Cancer Center, Professor of Plastic Surgery, Morsani College of Medicine, University of South Florida, Tampa, Florida; ǁCancer and Blood Disorders Institute, Johns Hopkins All Children's Hospital, St. Petersburg, FL; **Florida Dermatology and Skin Cancer Centers, Winter Haven, FL; and ††Department of Pathology, Loyola University Chicago Stritch School of Medicine, Maywood, IL.

A 17-year-old female presented for excision of a “ruptured cyst” on her right frontal scalp that had been growing over a month.

Clinical appearance of the subcutaneous mass during subtotal excision revealed friable serosanguinous translucent ribbons of tissue rather than cystic structures. Histopathologic analysis demonstrated a proliferation of histiocytic cells with mitotic figures, zonal necrosis, eosinophils, and focal osteoclast-like giant cells. Immunohistochemistry staining was positive for Vimentin, S100, CD1a, CD68 and CD 207. Laboratory testing (LDH, ESR, TSH/T4, and urinalysis) was essentially normal. Complete blood count with differential was normal except for mild thrombocytosis. At three-week follow-up, the patient noted sudden painful lymphadenopathy. Imaging studies revealed tumor extension from the scalp into the inner and outer tables of the calvarium with extradural invasion. Prominent lymphadenopathy was seen within the supraclavicular and cervical chains. Palatine tonsillar enlargement was also noted. Skeletal survey and chest X-ray did not show bony involvement. Based on the clinical, histological and imaging findings, the patient was diagnosed with multifocal Langerhans Cell Histiocytosis - eosinophilic granuloma with intracranial extension and massive lymphadenopathy. After evaluation with oncology, the patient and family opted for clinical monitoring since the scalp lesion and lymphadenopathy were now asymptomatic and minimized in size.

Rare Lymphatic Malformation of External Ear Canal With History of Sclerotherapy

Shannon Rodgers and Jason Pimentel

Department of Pathology, Henry Ford Health System, Detroit, MI.

An 8-year-old boy with history of conductive hearing loss, presented with a 3.1 x 3.1 x 2 cm left postauricular mass diagnosed as lymphatic malformation on imaging. Treatment with bleomycin sclerotherapy led to successful improvement of the malformation. Seven months post-treatment, he presented to his audiologist with several months of intermittent bleeding and pain from the ear. Upon examination by otolaryngology, a 0.5 cm papillary lesion was discovered in the external ear canal which had not been identified previously. A biopsy demonstrated a papillary proliferation of dilated thin walled lymphatic channels expanding multiple dermal papillae, consistent with lymphatic malformation. We propose that this lesion could represent extension of the original lesion or a new lesion secondary to regional lymphatic damage from prior sclerotherapy. Lymphatic malformation is rare within the external ear canal. Moreover, this case developed after treatment by regional sclerotherapy. To our knowledge, this sequela has not been previously documented in the literature but may be underreported. Therefore, routine regional follow up may be warranted in any periauricular sclerotherapy for lymphatic malformation.

Extracutaneous Pyoderma Gangrenosum in an African American Woman

Gabriella Santa Lucia, Alexia Demaio, and Samantha Karlin

Department of Dermatology and Dermatologic Surgery, Medical University of South Carolina, Charleston, SC.

Rare extracutaneous manifestations of pyoderma gangrenosum (PG) are potentially fatal and difficult to diagnose. Successful diagnosis is based on integrating a combination of radiologic, histologic, and clinical findings. A 52-year-old female with a history of cutaneous PG and unidentified lung nodules was admitted to the hospital for severe tibial ulcerations. Repeat chest CT revealed new necrotic nodules and multiseptated consolations. Plan was to initiate Humira for cutaneous PG lesions, however concern for pulmonary infection warranted lung biopsy prior to starting immunosuppression. Histopathology of the left lower lobe biopsy showed dense neutrophilic inflammation with abscess formation and without granulomas. Atypical infection such as nocardia was suggested, ruling out vasculitis and rheumatoid nodules. The patient continued to deteriorate after linezolid and imipenem administration. Immunosuppressive therapy was initiated after lung histopathology matched that of cutaneous PG lesions, suggesting the nodules were an extracutaneous PG manifestation. Both cutaneous and pulmonary lesions improved on immunosuppression. Extracutaneous PG is a diagnosis of exclusion as it mimics other infectious pathologies. Initial reads of radiologic and histologic studies may be misinterpreted as infectious etiologies without careful clinical correlation. Delay in correct diagnosis can lead to significantly worse patient outcomes and extraneous medical workup.

A Novel Histologic Finding in a Rare Disease: Scarring Alopecia in Hereditary Mucoepithelial Dysplasia

Kerrie Satcher, MD, Jennifer Schoch, MD, and Addie Walker, MD

University of Florida, Department of Dermatology, Gainesville, FL.

Hereditary mucoepithelial dysplasia (HMD) is a rare, autosomal dominant disorder with characteristic cutaneous findings, non-scarring alopecia, ophthalmologic, and pulmonary disease. The culprit gene is unknown; diagnosis relies on clinical findings and family history. We describe a 13-year-old boy with an extensive family history of HMD, who presented with red scrotal and intertriginous plaques, diffuse xerosis, and alopecia with scale, consistent with a diagnosis of HMD. Scalp biopsy showed psoriasiform acanthosis with columns of parakeratosis overlying invaginations of superficial epidermis with dyskeratosis- features previously described in cutaneous HMD. Our patient's biopsy also demonstrated findings of scarring alopecia including dermal fibrosis, diminished sebaceous glands, follicular rupture, concentric perifollicular fibroplasia and mixed inflammation—features not previously described. Our case adds to the limited HMD literature by describing histologic features of scarring alopecia in a condition previously viewed as non-scarring. Recognition of these histologic findings may be a key step in diagnosing HMD, a rare disorder with important implications for visual and respiratory health.

Keloidal Plaques in A Patient With Diffuse Cutaneous Systemic Sclerosis

Jane Scribner, MD, Laura Winterfield, MD, MPH, and Jessica Forcucci, MD

Medical University of South Carolina, Charleston, SC.

A woman in her 50s with a history of diffuse cutaneous systemic sclerosis, previously managed by rheumatology with mycophenolate and IVIG, presented with a new onset of painful plaques on her chest, breasts and axillae. They progressed over 12 months and were not responsive to topical clobetasol. Biopsy demonstrated a proliferation of fibroblasts with hyalinized thick keloidal collagen bundles in a haphazard distribution extending from the mid-reticular dermis to the dermal-subcutaneous junction with sparing of the papillary dermis. A significant inflammatory infiltrate was not identified. Keloidal morphea, also known as nodular scleroderma, is considered one of rarest clinical forms of scleroderma. Keloidal morphea commonly presents as asymptomatic plaques favoring the chest, back, and proximal extremities, and arise in sclerodermatous areas. The histopathologic variants include sclerodermatous, keloidal, and mixed patterns. The etiology of keloidal morphea remains unclear, but may involve a genetic predisposition and keloidal response to inflammation of the skin in patients with scleroderma. The authors have no relevant relationships to disclose.

Unusual Case of Primary Cutaneous Adnexal Carcinoma With Negative P63 and P40

Shiyanbola O.O.,* and Rosa G.†

Departments of *Pathology, University of Wisconsin, Madison, and †Associated Pathologists/St Mary's Hospital, Madison, WI.

We present a case of primary cutaneous adnexal carcinoma in the left groin of a 75-year-old woman with no history of malignancy, demonstrating a cribriform/tubular morphology, with ER, PR and GATA-3 expression but negative for p40 and p63. An initial biopsy was diagnosed as adenocarcinoma, favor metastatic breast carcinoma. Repeat p40 and p63 stains on the excision were negative. Background mammary-like glands were not identified. CT of the chest, abdomen and pelvis, mammogram and MRI of the breast were negative. A PET scan was negative, with the exception of the groin lesion. After 24 months, the patient has had no visceral malignancy. There is extensive literature showing positive p63 and p40 as useful confirmatory markers for primary cutaneous adnexal carcinoma, with absence of staining supporting a metastasis. This case shows an immunophenotype incongruous with the literature - a primary adnexal carcinoma with both negative p63 and p40. While immunohistochemistry can be helpful in the work-up of adenocarcinomas involving the skin, this case highlights a potential pitfall.

“Fungal Melanonychia: A Melanoma Mimicker”

Oraine Snaith, MD, David Ullman, MD, Sixto Leal, MD, and Peter Pavlidakey, MD

Department of Pathology, UAB, Birmingham, AL.

A 54-year-old man presented to an outside dermatology clinic with an ecthymatous, papular eruption on the right hip and a linear pigmented band on the medial right great toenail. Both lesions had been present for approximately two years. The right hip lesion was compatible with dermatophytosis. The pigmented band on the great toe, however, was concerning for malignant melanoma as it did not resolve with nail-pairing. The patient was subsequently referred to the hospital dermatology department for biopsy evaluation of the toenail. Hematoxylin and eosin (H&E) staining demonstrated a viable nail matrix and no apparent melanocytic proliferation. Subsequent analysis with ancillary stains (Sox-10, MART-1, MITF, Fontana Masson) confirmed the absence of melanocytes. Further histologic examination with GMS fungal stain highlighted innumerable fungal elements with pseudohyphal and budding-yeast patterns consistent with fungal melanonychia. In hindsight, while the concerning clinical features necessitate a biopsy, the concurrent fungal infection of the right hip coupled with the clinical history may have provided clues to the diagnosis. Awareness of fungal melanonychia may allow clinicians to possibly avoid the need for morbid procedures.

Gamma Delta Phenotype: A Marker of Progression in Mycosis Fungoides?

Pooja Srivastava, and Viktoryia Kazlouskaya

University of Pittsburgh Medical Center.

Introduction: Clinical significance of gamma phenotype in Mycosis fungoides (MF) is not well known. Some studies suggest that gamma delta expression is an indicator of worse prognosis, while there are cases which do not show any significant disease progression.

Case Report: Eighty-three-year-old male with established history of MF (CD4+/CD8+) for eight years, was progressing towards tumor stage despite bexarotene and radiotherapy. Recent biopsies showed large cell transformation with numerous CD30+ cells and few epidermal and dermal gamma delta positive cells. Patient was started on brentuximab, but he progressed and developed nodular lesions. The current biopsy demonstrated deep and diffuse atypical infiltrate compatible with tumor stage of MF with increased expression of CD30 and diffuse gamma expression. TCR gene rearrangement studies showed similar clone as seen previously, along with an additional peak in TCRG-A. The patient was started on Pralatrexate which led to improvement in the lesions.

Conclusions: We have observed a different clinical course in a patient with gamma delta MF. We think more research is needed to assess if gamma expression is an independent factor influencing the outcome in MF.

Case of Voriconazole-Induced Pseudoporphyria

Sarah Telliard MD and Tammie Ferringer MD

Geisinger Medical Center, Danville, PA.

Background: Pseudoporphyria, a photodistributed bullous disorder with similar features to porphyria cutanea tarda (PCT) but without porphyrin abnormalities, has been attributed to chronic renal failure/dialysis, UVA radiation, and numerous medications.

Case: A 44-year-old male with history of idiopathic aplastic anemia status post allogenic hematopoietic stem cell transplant, complicated by chronic GVHD was referred for blisters on his hands, first noticed four months after transplant. Blisters were exacerbated by sunlight and trauma. He had tense vesicles and bullae, containing clear and hemorrhagic fluid, along with crusting on the dorsal hands. Biopsy revealed a pauci-inflammatory subepidermal blister. DIF was negative. His medications included duloxetine, ibrutinib, IVIG, multivitamin, penicillin, pentamidine, rituximab, sirolimus, valacyclovir, vancomycin, vitamin D, and voriconazole. His clinical and histologic findings reminiscent of PCT, developing after starting voriconazole, were consistent with voriconazole-induced pseudoporphyria. This medication could not be discontinued given its necessity for post-transplant antifungal prophylaxis, so he was counseled on use of broad-spectrum sunscreens, as well as sun and trauma avoidance.

Discussion: This case highlights the importance of considering pseudoporphyria in patients on voriconazole, a second-generation azole antifungal agent, who develop a photodistributed vesicobullous eruption.

INI1 Expression in Stage III and Stage IV Metastatic Melanoma

Brandi Davis, Victoria. C. Vaughan, and Michael R. Clay

University of Colorado Department of Pathology, Aurora, CO.

The objective of the abstract is to determine expression of INI1/SMARCB1 (SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1) in metastatic stage III and stage IV melanoma. Prior investigations in stage III disease have demonstrated maintained INI1 expression. Given the recent approval of a drug for malignancies deficient in INI1 or SMARCA4, it is timely to reconsider the utility of these immunohistochemical studies in disease management. We identified 31 cases of stage III (29%) and stage IV (71%) melanoma from our archives within the past two years which were appropriate for review. Tissue blocks were then tested for immunohistochemical expression of the nuclear stain INI1 with appropriate tissue matched and internal controls. This is a preliminary survey of one of the many SWI/SNF proteins which could be altered in metastatic melanoma.

An Unusual Case of Metastatic Malignant Melanoma With Aberrant CD56 Expression

Karah D. White, Amy M. Kerkvliet, and Ali D. Jassim

University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota.

Melanoma is the sixth most common malignancy diagnosed in the United States. Histologically, melanoma can be very diverse, which can often make the diagnosis challenging. Though the use of immunohistochemistry can be helpful in these circumstances, aberrant or anomalous staining in melanoma can occur and may complicate definitive diagnosis. Melanoma has been reported to exhibit many types of differentiation including fibroblastic or myofibroblastic, Schwannian, smooth muscle, rhabdomyoblastic, osteocartilaginous, ganglionic and ganglioneuroblastic, epithelial, and neuroendocrine. We report a case of a 36-year-old male who was diagnosed with metastatic melanoma of the liver that not only expressed typical melanoma markers including MART-1, SOX-10, S100, and HMB-45, but also showed positivity for vimentin and aberrant expression of CD56, a neuroendocrine marker. Very limited reports of this finding are found in the medical literature. Therefore, it is important to recognize that melanoma may show aberrant expression of CD56, as this could be a potential diagnostic downfall, especially when the neoplasm is identified in a non-cutaneous location.

Exceedingly Rare Case of Acral Melanoma in a 15-Month-Old

Karah White and Ali Jassim

University of South Dakota Sanford School of Medicine.

Cutaneous malignant melanoma is rare in children and adolescents and accounts for only 1.3% of cases in the United States. Merely 0.3-0.4% occur during the first decade of life. Congenital and infantile melanoma most often occurs in the head and neck. Superficial spreading and nodular melanoma are the most common histologic subtypes. Acral melanomas have been described, but are exceedingly rare. We report a case of acral melanoma in a 15-month-old child. Physical examination showed a large black papule on the plantar foot with an adjacent satellite lesion. Initial biopsy was concerning and complete excision revealed an atypical compound melanocytic proliferation with pagetoid migration and sheets of atypical melanocytes forming nodules within the dermis and extension into the subcutaneous fat. The melanocytes showed diffuse positivity for HMB-45 and significant loss of p16 expression. This diagnosis was rendered with hesitance and difficulty, as melanoma is rare in this age group and location. Therefore, a high level of suspicion and awareness of the pathologic criteria used to differentiate benign and malignant melanocytic lesions is necessary to avoid delayed diagnosis and treatment.

Avoid Making A Diagnosis “Off the Cuff”

Grant Williams, MD and Nathaniel Smith, MD

Brooke Army Medical Center, San Antonio, TX.

A 17-year-old male presented with a 2 cm forehead mass present for 2 years. Clinically, the mass was favored to be a lipoma. On excision, the lesion consisted of well circumscribed histiocytoid cells with mild pleomorphism and a prominent lymphoplasmacytic cuff.

The community pathologist performed microorganism special stains, which were negative. At this point the lesion was assumed to be a hematopoietic neoplasm, prompting a hematopathology and hematology-oncology consultation. Tumor cells were positive for CD163 and Desmin and negative for Lu-5 and SMA. An EWSR1-CREB1 fusion was identified and a diagnosis of angiomatoid fibrous histiocytoma (AFH) was rendered. AFH usually arises in the extremities of young adults and teenagers. In this case, the characteristic dense lymphoplasmacytic cuff surrounding the tumor was initially confused for a hematopoietic neoplasm or infectious process. Community pathologists should be aware of this entity and the fact that it can present on the scalp and forehead to properly guide immunohistochemical staining and correct clinical follow up. These lesions can recur and rarely metastasize, so appropriate follow up is necessary.

Pili Multigemini of the Eye: Unusual and Rare Presentation

Zia S., MD, Rodgers S., DO, Kasturi S., MD, and Ormsby A., MD

Department of Pathology. Henry Ford Health System, Detroit, MI.

Pili Multigemini (PM) is an uncommon, pilar dysplasia characterized by clusters of hair shafts emerging from a single follicle. We present a rare and unique case of PM involving the eye. A 43 year old Caucasian male, presented with a prolonged history of a recurrent lesion at the right upper eyelid, present for two years. Clinical examination revealed a subcutaneous cyst with a prominent follicular pore with a differential diagnosis of epidermoid cyst, nevus and pili bifurcati. Excisional biopsy was performed and microscopy showed a benign malformed hair follicle containing multiple different hair shafts enclosed in a common outer root sheath; consistent with the diagnosis of Pilli Multigemini. Pili Multigemini was first described by Flemming in 1883 and is frequently found in the beard of adults and scalp of children. To our knowledge, this is the first case of Pilli Multigemini involving the eye. its noteworthy to consider during diagnostic workup; as well as to exclude other follicular and inflammatory abnormalities involving the eye.

A Case Report of Eccrine Syringofibroadenoma

Hong Jiang and Ruifeng Guo

Pathology Department of Mayo Clinic.

Eccrine syringofibroadenoma is a rare benign adnexal tumor with eccrine sweat duct proliferation. Less than 80 cases have been reported, either associated with reactive, neoplastic or syndromic settings. Due to it rarity and variable clinical presentation, it is easily misdiagnosed without pathology exam. Here we report a case of eccrine syringofibroadenoma. A 48-year-old African-American male with personal history of diabetes, hypertension and diabetic glomerulosclerosis and remote history of local treated cutaneous wart at right heel presented to dermatology clinic for the recurrent slow growing, enlarged wart. The cutaneous excisional biopsy shows peculiar histological features including thin anastomosing strands arising from the epidermis, bland cytomorphology, fibrovascular stroma, and lace-like architecture. Although architectural features mimic a relative common cutaneous lesion, fibroepithelioma of Pinkus, a variant of basal cell carcinoma, focal eccrine ductal differentiation and eccrine immune profile supports the diagnosis of syringofibroadenoma.

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