[A case report of anorectal malignant melanoma showing a complete response after DTIC/ACNU/VCR therapy]

We report herein the case of a 64-year-old male who presented with hematochezia. The patient was diagnosed with malignant melanoma of the anorectum using colonoscopy. Preoperative studies revealed no distant metastases, and he underwent Miles operation. Pathological exams revealed that the tumor had invaded the submucosa with lymphatic and venous invasion. Cancer cells were found in regional lymph nodes. Post-operative CT scan demonstrated multiple metastases in the liver, and he received two courses of combined chemotherapy, DAV regimen (dacarbazine: DTIC 100 mg iv days 1-5, nimustine hydrochloride: ACNU 100 mg iv day 1, vincristine sulfate: VCR 1 mg iv day 1), leading to a complete response. However, malignant melanoma cells were found in hernia contents at the operation for left inguinal hernia, which led to a diagnosis of recurrent malignant melanoma. The patient has subsequently been well without any sign of recurrence including liver metastases. To our knowledge, this is the first report of a complete response in a patient with multiple liver metastases of anorectal malignant melanoma after DAV regimen.