Neurocutaneous melanosis. Case report and a brief review.

Neurocutaneous melanosis is a rare congenital syndrome characterised by large or numerous congenital pigmented naevi and excessive proliferation of melanin-containing cells in the leptomeninges. The process is diffuse or multifocal, and has a tendency to infiltrate the neural tissue and the cerebrospinal cord; remote metastases may occur. There is usually histological evidence of malignancy (cellular pleomorphism and mitotic activity). Involvement of the basal cisterns is apt to cause internal hydrocephalus, and the prognosis is grave even when there is no histological evidence of malignancy. We present the case history and necropsy findings of a baby boy with neurocutaneous melanosis, followed by a brief review.