MR-IMAGING OF SYMPTOMATIC NEUROCUTANEOUS MELANOSIS IN CHILDREN

Neurocutaneous melanosis is a syndrome consisting of cutaneous nevi an d melanocytosis of the leptomeninges. Over a 5-year period (1989-1994) we evaluated with MR imaging the central nervous system of five child ren with a confirmed histologic diagnosis of neurocutaneous melanosis. The children ranged in age from 7 to 10 years and consisted of two gi rls and three boys. They all had multiple pigmented skin lesions (cuta neous nevi) and presented with seizures, signs of raised intracranial pressure, cranial nerve palsies and/or myelopathy. The MR studies were performed with T1-weighted, T2-weighted and T1-weighted post-gadolini um images of the brain in addition to T1-weighted post-gadolinium imag es of the entire spine. The MR findings in all the children consisted of marked, diffuse enhancement of thickened leptomeninges surrounding the brain and spinal cord which was only demonstrated on the post-gado linium T1-weighted images and mild to moderate hydrocephalus. We prese nt our MR findings and compare these findings with other imaging findi ngs in the literature. Our findings represent part of a spectrum of im aging abnormalities seen in patients with neurocutaneous melanosis.