Melanoma of the anorectal region.

Anorectal melanomas are more aggressive and behave differently from melanomas of the skin. Abdominoperineal amputation of the rectum is the favored procedure for potentially curable patients. Local recurrence in anorectal melanoma is less frequent in patients treated by local or wide excision of the tumor. Improvement in the primary anorectal melanoma survival rate appears to be dependent closely upon early diagnosis. Assessing the penetration of the tumor by the microstaging technique provides important prognostic information and serves for establishing indications for abdominoperineal amputation of the rectum in patients with primary anorectal melanoma. Two patients had a five year local and regional control of a primary anorectal melanoma achieved by abdominoperineal amputation of the rectum without groin dissection. One patient, free of disease, had an adenosquamous carcinoma of the lung develop with metastases to the skin. The carcinoma of the lung was considered as a secondary primary, which caused the death of the patient five years and nine months after the abdominoperineal amputation of the rectum.