Original ArticlesAL Amyloidoma of the Skin/Subcutis Cutaneous Amyloidosis, Plasma Cell Dyscrasia or a Manifestation of Primary Cutaneous Marginal Zone Lymphoma?Walsh, Noreen M. MD, FRCPC, FRCPath (UK)*,†,‡; Lano, Ian Marie MD, FRCPC*; Green, Peter MD, FRCPC†,‡; Gallant, Christopher MD, FRCPC†,‡; Pasternak, Sylvia MD, FRCPC*,‡; Ly, Thai Yen MD, FRCPC*,‡; Requena, Luis MD§; Kutzner, Heinz MD∥; Chott, Andreas MD¶; Cerroni, Lorenzo MD#Author Information Departments of *Pathology †Medicine, Nova Scotia Health Authority (Central Zone) ‡Department of Pathology, Dalhousie University, Halifax, NS, Canada §Department of Dermatology, Fundación Jiménez Díaz, University Hospital La Princesa, Madrid, Spain ∥Dermatopathology Friedrichshafen, Friedrichshafen, Germany ¶Institute of Pathology and Microbiology, Wilhelminenspital, Vienna, Austria #Department of Dermatology, Research Unit Dermatopathology, Medical University of Graz, Graz, Austria Conflicts of Interest and Source of Funding: The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article. Correspondence: Lorenzo Cerroni, MD, Department of Dermatology, Research Unit of Dermatopathology, Medical University of Graz, Auenbruggerplatz 8, Graz A-8036, Austria (e-mail: firstname.lastname@example.org). The American Journal of Surgical Pathology: August 2017 - Volume 41 - Issue 8 - p 1069-1076 doi: 10.1097/PAS.0000000000000861 Buy Metrics Abstract It is unclear whether AL amyloidoma of the skin/subcutis represents a distinct entity, an indolent precursor of systemic amyloidosis, or a manifestation of cutaneous marginal zone lymphoma (cMZL). We collected 10 cases of cutaneous AL amyloidoma in order to better characterize the clinicopathologic features of this elusive entity (M:F=4:6; median age: 62.5 y, range: 31 to 82 y). Nine patients had a solitary nodule or plaque on the lower extremity (n=7), upper extremity (n=1), or chin (n=1). One patient had an AL amyloidoma on the right thigh and a second lesion on the right arm showing histopathologic features of cMZL without amyloid deposits. Clinical investigations excluded relevant systemic disease in all cases. Microscopically, dermal/subcutaneous deposits of amyloid were associated with sparse to moderate perivascular infiltrates of lymphocytes and monotypic plasma cells (7 with kappa and 3 with lambda light chain restriction). The plasma cells expressed CD56 in one of 9 studied cases. One case was characterized by a t(14;18)(q32;q21)/IGH-MALT1 translocation. Follow-up was available in 8 cases. All remain systemically well after a median time of 86.5 months (range: 40 to 144 mo). Local recurrence of disease was observed in 3 patients. A fourth patient presented with a cMZL without amyloid deposits 8 years after excision of the cutaneous AL amyloidoma. Although our series is small, careful categorization and follow-up of the cases, together with updated information in the literature, show clinical and biological links between AL amyloidomas of the skin/subcutis and cMZL, suggesting that at least a subset of cutaneous AL amyloidoma may represent an unusual manifestation of cMZL (cutaneous mucosa-associated lymphoid tissue lymphomas). Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.