Meningeal melanocytoma with invasion of the thoracic spinal cord. Case report.

A case is presented of meningeal melanocytoma that invaded the thoracic spinal cord of a 71-year-old woman. The light and electron microscopic features of the lesion indicate that it derives from melanocytes normally found in the leptomeninges. This tumor closely resembles the dermal cellular blue nevus and does not have the ultrastructure of a meningioma. "Melanotic meningioma" is consequently a misnomer and the name "meningeal melanocytoma" is more appropriate. These tumors may appear to be benign histologically, but they are locally aggressive. Total surgical excision offers the best chance for cure.