Neurocutaneous melanosis with hydrocephalus, intraspinal arachnoid collections and syringomyelia: case report and literature review.

Neurocutaneous melanosis (NCM) is a rare nonfamilial syndrome, characterised by large or numerous congenital pigmented nevi and excessive proliferation of melanin-containing cells in the leptomeninges. We report the MR findings in the brain and spine of a child with NCM who underwent neurosurgical treatment and was followed up for 8 years. The findings in this child (small hyperintense collections of melanocytes in both temporal lobes, mild meningeal enhancement along the spine and the development of an extensive subarachnoid CSF accumulation with cord compression and syringomyelia) are believed to be exceptionally rare.