Amelanotic malignant melanoma of the rectum: Report of a case

We describe herein a case of amelanotic melanoma of the rectum. Macroscopic ally, the tumor was lacking in pigmentation and microscopically, it was fou nd to be deficient in melanin. Moreover, the tumor cells showed positive st aining for HNB-45, the antimelanoma antibody, which led to a diagnosis of a melanotic melanoma. The patient died of metastatic tumors in the liver and bone 17 months after undergoing abdominoperineal resection of the rectum an d dissection of the bilateral inguinal lymph nodes.