A successfully treated malignant melanoma arising in a large congenital vulvar blue nevus

An atypical cellular blue nevus, a benign mass, may sometimes transform into a malignant melanoma. Here, we report a rare case of melanoma arising in a large congenital vulvar blue nevus. A 28-year-old Chinese woman presented to our hospital with a chief complaint of a vulvar mass that had persisted for 8 years. The patient underwent extensive local excision, followed by reconstructive surgery of the female reproductive tract. The mass was diagnosed as being a vulvar malignant melanoma. Postoperatively, the patient received interferon immunotherapy and recovered without complications. No evidence of recurrence was observed after 32 months of follow-up. Our case thus shows that comprehensive treatment with surgery supplemented by immunotherapy can be effective against a malignant melanoma arising in a vulvar blue nevus.