[Case of primary amelanotic malignant melanoma of the female urethra]

We report a rare case of primary amelanotic malignant melanoma of the female urethra. A 58-year-old female with complaint of nodule on the external urethral meatus was referred to our hospital. Pathological diagnosis of the biopsy specimen from the nodule was malignant melanoma. Computed tomography of the chest and abdomen as well as bone scan showed no evidence of metastasis. Sentinel biopsy from the inguinal lymph nodes revealed no metastasis. Thereafter, the patient underwent radical urethrectomy, whose limits of resection were the bulbocavernosal muscles bilaterally, the arch of the pubic symphysis anteriorly, the anterior vaginal wall posteriorly, and the urethra up to the level of the bladder neck superiorly. The histopathological diagnosis was amelanotic malignant melanoma of the urethra. The patient had received six cycles of DAV-Feron (dacarbazine, nimustine, vincristine, and interferon-beta) in an adjuvant setting, and there is no sign of recurrence 25 months after operation.