Congenital Melanocytic Nevi Syndrome With Leptomeningeal Melanoma.

The incidence of congenital melanocytic nevi (CMNs) is 1% to 6% for small- to intermediate-size nevi to 1 in 500,000 for giant size nevi. Large and satellite CMNs are known to be associated with neurocutaneous melanosis and central nervous system malformations such as Dandy-Walker malformation, defects of the vertebra-skull, and intraspinal lipomas. We hereby present a case of CMN syndrome in an 18-year-old girl with leptomeningeal melanoma, evaluated with MRI, adequately staged, and screened with FDG PET.