Malignant Melanoma of the Anorectum: A Bizarre Presentation

Abstract

Anorectal melanoma is a rare malignancy accounting for only 1-2 % of anorectal tumors. The absence of early clinical manifestations and the lack of clinical suspicion contributes for delayed diagnosis. Owing to its rarity and histologic variability, misdiagnosis as lymphoma, carcinoma, or sarcoma is common. The propensity of MM to metastasize early, diffusely and unpredictably is responsible for invariably disappointing outcomes.