A rare case of melanoma of the rectum hemorrhoid nodule

Abstract

Anorectal melanoma (AM) is an aggressive and very rare malignancy. The aim of this case report is to present a case of anorectal melanoma that occured in hemorrhoidal node after a colorectal surgery. A patient aged 69 years was treated at the Oncology Institute of Vojvodina for histopathological (HP) verified melanoma of the anorectum (S100, HMB45 and Melan A positive) localized in the hemorrhoidal node. Wide local excision was made. Three months after the operation secondary deposits ocurred at the site of the colorectal anasthomosis, stomach, lung and brain. Polymerase chain reaction analysis of tumor DNA found no mutation in the BRAF V600 gene. Five months after the operation the patient is still alive and on supportive and symptomatic therapy. Despite its rarity, AM should always be considered in unusual anorectal lesions first at all in hemorrhoid nodules.