Malignant melanomas of the vagina are rare tumors. In this study we present the clinicopathologic features and immunohistochemical analysis of 26 such cases seen in our institution over a period of 30 years. The patients' age ranged from 38 to 90 years (mean 60 years); three patients were premenopausal. Ethnicity was known in 24 patients: 20 white, 2 hispanic, 1 black, and 1 Asian. The most common presenting symptom was vaginal bleeding, followed by vaginal mass. Grossly, the tumor was polypoid-nodular in the majority of cases. The neoplastic cells were epithelioid in 15 cases and spindled in three cases; eight cases had both cell types. Vascular-lymphatic invasion was seen in six cases and perineural invasion was seen in four cases. S-100 was strongly and diffusely positive in 25 of 26 cases (96%). HMB-45 was strongly positive in 16 (62%), 3 (11%) were focally positive, 1 case showed a rare positive cell, and 6 (23%) were negative. With MART-1, 20 cases (77%) were strongly positive, 1 (4%) showed a rare weakly positive cell, and 5 (19%) were negative. Twenty-one cases (81%) expressed tyrosinase and 20 (77%) expressed microphthalmia transcription factor. Twenty cases were Chung's level IV, 3 were level III, and 2 were level II. The patients were treated as follows: anterior exenteration with or without lymph node dissection and with or without radiotherapy (RT) or chemotherapy (CT) (7 cases), wide local excision with or without lymph node dissection and RT/CT (10 cases), hysterectomy with vaginectomy with or without RT/CT (3 cases), vaginectomy with RT (1 case), RT (1 case), and RT and CT (1 case). One patient had palliative RT for the brain metastasis only. Follow-up was available in 23 patients ranging from 3 to 276 months (median 18 months). Local recurrence after primary treatment was seen in six patients and distant metastases in 11 patients. Fifteen patients died of the disease (3-83 months), 4 have no evidence of disease (5-24 months), and 4 are alive with disease (6-276 months). This study confirms the poor prognosis of patients with vaginal melanoma. S-100 remains the most sensitive marker for these tumors. HMB-45 is negative in 23% cases of vaginal melanoma. Tyrosinase and MART-1 are useful markers when S-100 is negative or only focally positive.
- HMB- 45
- Microphthalmia transcription factor
ASJC Scopus subject areas
- Pathology and Forensic Medicine