[A case report of long-term survival in the patient with anorectal malignant melanoma].

Malignant melanoma of the anorectal region is rare, and the prognosis is considered to be poor. We present a case of long-term survival in a 56-year-old patient with primary malignant melanoma in the anorectal area, who complained of anal bleeding. Barium enema showed an elevated lesion in the anorectal region. Colonoscopy revealed a 3 cm sessile tumor with focal pigmentation, and a satellite nodule, 1 cm in diameter. Based on diagnosis of malignant melanoma by biopsy, abdominoperineal resection with lateral node dissection was performed. Pathologically the tumor remained in the mucosa, and no lymph node metastasis was found. This patient refused any adjuvant chemotherapy after the operation, and remains well without any sign of recurrence for seven years.