Anorectal melanoma. Case report and review of the literature.

We report a case of primary anorectal melanoma, a very rare malignant tumor in this localization. The patient, a 57-year-old female, complained for one year of symptoms, which were attributed to hemorrhoids. An abdomino-perineal resection was performed. Pathologic examination revealed an anorectal melanoma with numerous lymph node metastases and an unusual metastatic deposit in a uterine leiomyoma. The pathogenesis, pathology, principles of treatment and prognosis of this entity are briefly discussed.