Supratentorial dorsal cistern epidermoid cyst in childhood.

Epidermoid cysts (ECs) are rare developmental lesions occurring anywhere along the central nervous system. Usually affecting adult patients, the occurrence of supratentorial dorsal cistern ECs has been reported in only 1 certain case of pediatric age. An additional pediatric case is presented. An 11-year-old boy had an 8-year history of petit mal seizures. Neurologic examination on admission was negative. T1-weighted magnetic resonance images demonstrated homogenous, hypointense, intradural, extracerebral, right frontal, precentral, parasagittal mass with relatively high signal intensity on T2-weighted images. The lesion was completely removed using a microneurosurgical technique with special care taken with regard to the adjacent nervous and vascular structures. Histologically, an EC was diagnosed. The patient had no recurrence for 2 years and seizures were significantly reduced. This case suggests the need to include ECs in the differential diagnosis of intradural supratentorial extracerebral lesions in childhood.