LUMBAR SPINAL INTRADURAL EPIDERMOID CYST

Epidermoid cysts are rare intradural extramedullary tumors. There are two types of lesions : congenital spinal cysts frequently associated w ith other bone or skin malformations (spina bifida aperta, dermal sinu s...) and iatrogenic spinal cysts resulting from lumber puncture. In b oth situations, clinical and the radiologic findings are similar. We d escribe an epidermoid cyst in a 52-year-old female affected with a lum bar pain and recent urinary disorders. Symptoms were slow to appear an d dependent on the location of the cyst. Epidermoid cyst contained ker atin, cholesterol crystals and desquamed epithelial cells. On CT, epid ermoid cyst was a hypodense lesion on MR. On T1 weighted images the tu mor was hypointense. The signal appeared heterogeneous. There was no e nhancement after Gadolinium DTPA injection. Differential diagnosis inc luded: ependymoma, hemangioblastoma, neurinoma, meningioma and metasta sis, but all these lesions are enhanced by contrast injection.