Original ArticlesLocalized Peritumoral AL Amyloidosis Associated With Mantle Cell Lymphoma With Plasmacytic DifferentiationYabe, Mariko MD, PhD*; Ozkaya, Neval MD*; de Jong, Daphne MD†; Aypar, Umut PhD‡; Ritorto, M. Stella PhD*; Barbé, Ellis MD†; Miedema, Iris H.C. MD†; Sen, Filiz MD*; Chapman, Jessica R. PhD*; Landau, Heather J. MD§; Dogan, Ahmet MD, PhD*Author Information *Hematopathology Service ‡Cytogenetic Service, Department of Pathology §Myeloma Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY †Department of Pathology, Amsterdam UMC, location VU University Medical Center, Amsterdam, The Netherlands Conflicts of Interest and Source of Funding: Supported in part through the NIH/NCI Cancer Center Support Grant P30 CA008748 and NIH/NCI MSK Lymphoma SPORE P50 CA192937 (A.D.) and Farmer Family Foundation (A.D.). M.Y. has received personal consultancy fees from Janssen Research and Development LLC. D.d.J. has received personal consultancy fees from Celgene, Takeda, and BMS. H.J.L. has received personal consultancy fees from Celgene, Janssen, Sanofi, Pfizer, Takeda, Abbvie, and Spectrum pharmaceuticals; and research support from Takeda. A.D. has received personal consultancy fees from Roche, Corvus Pharmaceuticals, Physicians’ Education Resource, Seattle Genetics, Peerview Institute, Oncology Specialty Group, Pharmacyclics, Celgene, Novartis, Takeda, EUSA Pharma, and research grants from National Cancer Institute and Roche. The remaining authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article. Correspondence: Mariko Yabe, MD, PhD, Hematopathology Service, Department of Pathology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, MRI-1007C, New York, NY 10065 (e-mail: [email protected]). The American Journal of Surgical Pathology: July 2021 - Volume 45 - Issue 7 - p 939-944 doi: 10.1097/PAS.0000000000001684 Buy Metrics Abstract Immunoglobulin light chain (AL) amyloidosis is characterized by the deposition of amyloid fibers derived from pathologic immunoglobulin light chains. Although systemic plasma cell neoplasms are the most common cause of AL amyloidosis, a subset of cases is caused by B-cell lymphoproliferative disorders such as lymphoplasmacytic lymphoma or extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue. Recently, SOX11-negative IGH hypermutated mantle cell lymphoma (MCL) is recognized to show frequent plasmacytic differentiation and indolent clinical course. Here, we report 3 cases of peritumoral AL amyloidosis associated with SOX11-negative MCL. All 3 cases showed cyclin D1 expression by immunohistochemistry and CCND1 translocation as detected by fluorescence in situ hybridization analysis. Peritumoral AL amyloidosis was observed at the biopsy sites in the gastrointestinal tract, a supraclavicular lymph node, and a cervical lymph node, and all presented with marked plasmacytic differentiation of lymphoma cells. None of the cases showed evidence of bone marrow involvement by morphology and immunophenotyping. None of the patients had distant organ involvement with systemic amyloidosis. All 3 patients had an indolent clinical course and are alive with disease at the time of the last follow-up (range: 48 to 74 mo). Our findings show that MCL with plasmacytic differentiation can cause amyloid deposition and CCND1 abnormalities should be performed in all cases of extramedullary AL amyloidosis. Recognition of indolent MCL as a cause of peritumoral AL amyloidosis may have important clinical management implications. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.