Pagetoid lesions of the vulva: a collision between malignant melanoma and extramammary Paget disease.

Vulvar extramammary Paget disease (EMPD) is an intraepithelial carcinoma not frequently seen in conjunction with other primary tumors. Nevertheless, we are presenting a collision between malignant nodular melanoma and EMPD in the vulva of a 78-year-old gravida 6, para 6 woman with a medical history of chronic lymphocytic leukemia. The patient presented with vulvar irritation and a pigmented vulvar mass; biopsy confirmed the diagnosis of malignant melanoma. Peripheral to the main mass, the vulva grossly seemed erythematous, and the perineum seemed white and thickened. Multiple radial biopsies were taken to determine the extent of involvement by malignant melanoma, and these biopsies revealed that the "irritated" areas surrounding the melanoma were EMPD. Subsequently, a radical vulvectomy was performed, the margins of which were clear of both neoplasms. Five months later, bilateral groin adenopathy was biopsy proven to be metastatic melanoma and chronic lymphocytic leukemia, and the patient died 8 months after the radical vulvectomy.