PRIMARY ANORECTAL MELANOMAS - AN INSTITUTIONAL EXPERIENCE

Primary melanomas (M) of the rectum and anal canal are a rare patholog ical event, constituting approximately 1% of all invasive tumors in th is site. From January 1973 to December 1990 at the Istituto Nazionale per lo Studio e la Cura dei Tumori of Milan, 11 patients were treated for M (5 males and 6 females), with a mean age of 60 years (range 40-8 0). The site of origin of the M was rectal in four patients, anal in f ive patients and in the anorectal joint in two patients. The lesion wa s prevalently polypoid and the average size was 4 cm (1-7.5 cm). Sympt oms referred by the patients were rectal bleeding and tenesmus. In one patient the diagnosis was made after biopsy of an inguinal metastatic lymphnode. Of the II patients, six underwent curative resection (four Miles' resections and two local excisions). One patient is still aliv e with no evidence of disease after 120 months. The remaining five pat ients were submitted to palliative treatment, due to the presence of m etastases in four of them and to age and general conditions in one. Al l of these patients died at 1, 2, 4, 5, and 6 months (median: 4 months ). Overall median survival was eight months: 20 months in the radicall y treated group and four months in the palliatively treated group. Our data are in agreement with those reported in literature and confirm t he prognostic severity of anorectal M due both to late diagnosis and t he biological aggressiveness of the neoplasm.