UNCOMMON ANORECTAL PATHOLOGY: ANORECTAL MELANOMA

Anorectal melanoma (AM) is a rare and aggressive tumor, characterized by a poor prognosis. It accounts for 0.4–1.6% of all melanomas, and only 1% of anorectal malignant tumors [1]. It is difficult to diagnose due to the hidden site and nonspecific symptoms, occurring usually at a late stage. The most common symptom is rectal bleeding. There are various histological variants of AM. There is currently no consensus of treatment the typical therapeutic approach remains surgical resection however, this is not associated with improved overall survival [2,3]. We present a case of a 52-year old male complaining of rectal bleeding and pain for about 4 months, which were attributed to hemorrhoids. Rectal examination revealed an irregular mass near the anal verge. Biopsies were taken for analysis, they were fixed in 10% formalin, paraffin embedded and routinely stained with Hematoxylin– Eosin. Immunohistochemical investigations were done by using antibodies against cytokeratin (CK), P40, HMB45 and Melan A.