Anorectal Melanoma: A Case Report

Abstract

Anorectal mucosal melanoma (AMM) is an infrequent and highly aggressive form of mucosal melanoma. Its rarity makes it challenging to clinically diagnose, and its initial symptoms are typically nonspecific such as rectal/anal bleeding (the most common symptom), anal pain, or the presence of an anal mass. The prognosis for this condition is generally poor, and its incidence appears to be increasing each year. AMMs often go undetected and/or are already metastasized at the time of diagnosis. We present a case report of a patient who initially presented with nonspecific symptoms of anemia and blood per rectum, and was later found to have stage IV melanoma of the anorectal region. There is a notable scarcity of literature on this disease, resulting in a lack of a comprehensive understanding of its nature. Most available information consists of isolated case reports rather than comprehensive studies. Although surgical resection remains the primary treatment approach, the majority of patients (over 80%) will die due to distant metastasis within five years after undergoing surgery. The five-year survival rate for anorectal melanoma is estimated to be between 6% and 22%.

Keywords: anorectal melanoma; malignant melanoma initial presentation; melanoma skin cancer; mucosal malignant melanoma; rectal malignant melanoma.