A retrospective clinical analysis of 5 cases of vaginal melanoma.

Vaginal melanoma is a rare tumor, accounting for <1% of all melanomas and ~1-5% of all vaginal malignant tumors. The prognosis of vaginal melanoma is extremely poor, as it is often resistant to chemotherapy and radiotherapy, and metastases may develop in the early stages of the disease. The present study investigated 5 patients with vaginal melanoma treated at the Department of Gynecology of Osaka City University Hospital (Osaka, Japan) between October, 2000 and April, 2014. All the cases presented with abnormal genital bleeding as the main complaint. Notably, in 3 of the 5 cases the tumors appeared as non-pigmented polyps. Local resection was performed as the primary treatment in all 5 cases. After surgery, dermal injection of interferon β (feron maintenance therapy) was performed in 3 cases, and dacarbazine, nimustine, vincristine and interferon β (DAVFeron therapy) was administered in 1 case as adjuvant therapy. All 5 cases recurred within 1 year. The site of recurrence varied, and included the vaginal wall, liver, brain and lung. The median overall survival was 419 days and the median progression-free survival 177 days. In this cohort, all the cases presented with abnormal genital bleeding as the main complaint. Therefore, malignant melanoma of the vagina must be considered along with other gynecological malignancies in patients with abnormal genital bleeding. In this study, over half of the cases had a non-pigmented polypoid lesion of the vagina. Therefore, malignant melanoma of the vagina must be considered when a polypoid lesion is identified on the vaginal wall.