Abstract
We report a case of pedunculated malignant melanoma arising in a medium-sized congenital melanocytic nevus. A 31-year old woman had a rapidly growing pedunculated tumor at the edge of a hairy black macule on her left thigh. The macule was 50×15mm in size at the initial presentation. Pelvic CT scan showed multiple regional node metastases. Wide local excision, therapeutic groin dissection, neo-adjuvant and adjuvant DAV-IFNβ therapy (DTIC, ACNU, VCR, IFNβ) were performed. Histological examination showed congenital melanocytic nevus coexisting with malignant melanoma of pT4aN1M0 stage III, thickness 9mm, level IV. After two courses of adjuvant therapy, multiple liver, brain, and lung metastases were recognized. She died of the disease 3 months after the operation. The present case indicated that even a medium-sized congential melanocytic nevus had a risk for malignant melanoma. [Skin Cancer (Japan) 2000; 15: 49-52]
