Late recurrence of malignant melanoma.

A patient presented with metastatic disease nearly 12 years after initial excision of a "benign" nevus. Review of the original slides confirmed malignant melanoma. Another patient was found to have a metastatic deposit of melanoma in the breast 23 years after an apparently adequate excision of a melanoma on the back. The natural history of this tumor shows its unpredictable nature. A thorough history and lifelong follow-up are essential in patients with malignant melanoma.