Abstract
Anorectal melanoma is a rare aggressive disease. Due to its rarity and considerable histologic and immunohistochemical variabilities, misdiagnosis as lymphoma, carcinoma, sarcoma, and/or gastrointestinal stromal tumor is not uncommon, particularly in amelanotic cases. We reviewed histologic features and immunohistochemical stains of 19 anorectal melanoma cases. Histopathologic features were evaluated including junctional activity, melanin pigment, and morphologic features. Immunohistochemical stains were performed using Sox10, S100 protein, HMB-45, melan-A, CD56, and cytokeratins. Epithelioid histopathologic morphology was observed in 63.2% of the cases followed by 47.4% of the cases with spindle-cell, 26.3% with lymphoma-like, and 26.3% with pleomorphic morphologies. Junctional melanocytic activity was seen in almost half of the cases. Melanin pigment was absent (amelanotic) in nearly 40% of the cases. Immunohistochemically, diffuse positive expression of Sox10, S100 protein, melan-A, and HMB-45 was seen in 100%, 40%, 53.3%, and 38.5% of the cases, respectively. Cytokeratins were negative and CD56 was positive in 2 cases. These findings indicate that anorectal melanomas often show one or combined histolopathologic features wit...Continue Reading
References
Oct 1, 1982·Diseases of the Colon and Rectum·P H CooperM S Allen
May 3, 2000·Histopathology·S S Banerjee, M Harris
Apr 11, 2008·Journal of Cutaneous Pathology·Steven J OhsieScott W Binder
May 1, 2006·Clinics in Colon and Rectal Surgery·Marc Singer, Matthew G Mutch
Apr 9, 2013·American Journal of Clinical Oncology·Lisa A KottschadeSvetomir N Markovic
Jun 12, 2013·Advances in Anatomic Pathology·Nelson G Ordóñez
Jun 19, 2013·Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology·F Stephen HodiDavid E Fisher
Aug 29, 2014·Annals of Diagnostic Pathology·Muhammad Usman TariqZubair Ahmad
Oct 31, 2014·Applied Immunohistochemistry & Molecular Morphology : AIMM·Brian C WillisCynthia Cohen
Nov 16, 2014·Journal of Clinical Pathology·Raffaella SantiDaniela Massi
Feb 28, 2015·The American Journal of Surgical Pathology·Markku MiettinenJohn F Fetsch
Jan 1, 2015·Dermatopathology·Leigh A ComptonChristine G Lian
Oct 16, 2016·Modern Pathology : an Official Journal of the United States and Canadian Academy of Pathology, Inc·Hui Min YangBasil A Horst
Nov 23, 2016·Journal of Cutaneous Pathology·Randie H Kim, Shane A Meehan
Citations
Jun 25, 2019·International Journal of Surgical Pathology·Phoenix D BellXiaoyan Liao
Mar 21, 2020·The American Journal of Dermatopathology·Yanqing Wang, Ying Guo
Dec 29, 2020·ANZ Journal of Surgery·Aikaterini MastorakiIoannis Papaconstantinou
Jul 17, 2021·Colorectal Disease : the Official Journal of the Association of Coloproctology of Great Britain and Ireland·Andrej KolosovAudrius Dulskas
Aug 5, 2021·Journal of Gastrointestinal Cancer·Jitendra Singh NigamJagjit Kumar Pandey