The purpose of this article is to describe experience with an uncommon condition in a single cancer center. There was a minor invasion of the lower canal in 17 patients. The histological types were 24 squamous cell and 7 basocellular carcinomas, and 1 Paget's disease. No prophylactic inguinal irradiation was delivered. Twenty-six percent presented a Grade 3 or 4 late complication, necessitating a temporary colostomy in only one patient.
Results are similar to other series, and seem better than for anal canal cancer.
We recommend exclusive irradiation. There is no data recommending concomitant chemotherapy. Surgery is reserved for small tumors far from the canal or for salvage. An inguinal prophylactic bilateral irradiation should be recommended for N0, with tumors over 4 cm. A biopsy of the mass revealed the proliferation of spindle- shaped cells with melanin pigments, and an abdominoperineal resection was performed, the histology of which confirmed malignant melanoma.