A melanoma arising from the anus. Clinical presentation includes rectal bleeding, tenesmus, pain, and change in bowel habit. The prognosis is usually poor. The disease is MONDO_0006081 (anal melanoma). Also known as: anal malignant melanoma, anus melanoma, anus melanoma (disease), malignant anus melanoma, malignant melanoma of anus, malignant melanoma of the anus, melanoma (disease) of anus, melanoma of anus.