[Neurocutaneous melanosis--a case report].

Neurocutaneous melanosis is a rare congenital phacomatosis characterized by the presence of large or multiple congenital melanocytic nevi and benign or malignant pigmented cell tumors of the leptomeninges. A 14-month-old boy was admitted with a recent history of vomiting and drowsiness. He was found to have multiple congenital melanocytic nevi. Gd-enhanced MRI showed ventriculomegaly and leptomeningeal enhancement in the ambient cistern. CSF cytology revealed abnormal cells with pigmented granules. A diagnosis of hydrocephalus with malignant neurocutaneous melanosis was made. The patient was treated with combination chemotherapy (DAV therapy, ACNU intrathecal perfusion therapy, interferon beta therapy) while controlling intracranial pressure by CSF drainage, but in spite of treatment he died due to rapid progression of leptomeningeal infiltration. Postmortem examination revealed meningeal malignant melanomas predominantly at the base of the brain and benign meningeal melanosis over the cerebral cortex. Newborn infants or infants with large or multiple congenital melanocytic nevi should be carefully followed, especially for the first two years. When hydrocephalus or convulsions occur in patients with skin lesions, Cd-enhanced-MRI and careful CSF cytology studies should be performed to detect meningeal abnormalities.