Anorectal malignant mucosal melanoma.

Anorectal mucosal melanoma (AMM) is a rare, aggressive malignancy. The symptoms of AMM mimic common benign conditions in the anus, such as haemorrhoids; hence diagnosis is often made late, a third of patients having metastasis at first presentation. Surgical resection remains the standard of treatment, and adjuvant therapy is varied, including immunotherapy, brachytherapy, and chemotherapy. The prognosis is poor, with a 5-year survival of 20%. A 65year old woman presented with a five-year history of symptoms suggestive of haemorrhoids and was diagnosed with a malignant anorectal mucosal melanoma after symptoms worsened and further investigation was performed. She underwent surgical resection and is currently receiving adjuvant therapy. The prognosis of AMM, the lack of consensus on the treatment regimen to date, and the need for a high index of suspicion for early diagnosis are discussed.

Funding: None declared.