Primary ano-rectal melanoma: considerations on a clinical case and review of the literature

Anorectal melanoma is a rare disease (1% of all anorectal malignancies). It is characterised by aspecific symptoms and the differential diagnosis versus other lesions of the rectum and anus is often difficult. The prognosis is very poor: mean survival is about 24 months, and at diagnosis most patients present distant metastases. Surgery is suggested as being the best treatment for this disease, since radio- and chemotherapy are generally only used for palliative purposes. Long-term survival depends on the stage of the melanoma at diagnosis. The possible surgical treatments available consist in local resection, which is considered the first therapeutic choice, and abdominoperineal amputation when local resection cannot be performed, or as a palliative operation. Inguinal lymphadenectomy is indicated when the inguinal lymph nodes are involved. In this report we describe a case of anorectal melanoma in a 73-year-old woman who underwent abdominoperineal amputation as surgical palliative treatment, because of infiltration of the puborectal muscle. The case report is followed by a review of the literature