NEUROCUTANEOUS MELANOSIS ASSOCIATED WITH INFERIOR VERMIAN HYPOPLASIA - MR FINDINGS

Objective: We describe the MR findings of two cases of neurocutaneous melanosis (NCM) associated with inferior vermian hypoplasia (IVH). Mat erials and Methods: Two cases of NCM associated with IVH are presented . Both patients had congenital giant hairy nevi and multiple satellite lesions. Results: Magnetic resonance imaging revealed IVH as well as hyperintensities in the pons and the cerebellar leptomeninges on T1-we ighted images. The hyperintensities may be ascribed to the T1-shorteni ng effect of melanin. A right parietal tumor in one patient and unilat eral ventriculomegaly in another patient were also depicted. Conclusio ns: Magnetic resonance demonstration of the T1-shortening leptomeninge al infiltrations adds weight to the diagnosis of NCM. The implication of the concurrence of NCM and IVH is discussed.