[A case of neurocutaneous melanosis associated with focal cortical dysplasia].

A newborn baby boy presented with giant melanocytic nevi on the face, trunk and extremities, and focal cortical dysplasia on MRI. At 3 months of age, he developed intractable epilepsy, and MRI at 2 years of age revealed a high-intensity area in the bilateral cerebellum on T1-weighted images, indicative of melanosis. Based on the findings of the skin and MRI, we diagnosed the boy with neurocutaneous melanosis. Cytodiagnosis of cerebrospinal fluid showed no malignancies. EEG, magnetoencephalogram and ECD-SPECT indicated that the clonic seizures originated from a focus in the right focal cortical dysplasia. Complications also included sebaceous nevus of the head and face, which was characteristic of sebaceous nevus syndrome, lipoma of the face and cauda equina, and limbal dermoid. Sebaceous nevus syndrome may have been due to certain allelic defects that were independent of those for neurocutaneous melanosis.