Lumbar spinal intradural epidermoid cyst.

Epidermoid cysts are rare intradural extramedullary tumors. There are two types of lesions : congenital spinal cysts frequently associated with other bone or skin malformations (spina bifida aperta, dermal sinus...) and iatrogenic spinal cysts resulting from lumber puncture. In both situations, clinical and the radiologic findings are similar. We describe an epidermoid cyst in a 52-year-old female affected with a lumbar pain and recent urinary disorders. Symptoms were slow to appear and dependent on the location of the cyst. Epidermoid cyst contained keratin, cholesterol crystals and desquamed epithelial cells. On CT, epidermoid cyst was a hypodense lesion on MR. On T1 weighted images the tumor was hypointense. The signal appeared heterogeneous. There was no enhancement after Gadolinium DTPA injection. Differential diagnosis included: ependymoma, hemangioblastoma, neurinoma, meningioma and metastasis, but all these lesions are enhanced by contrast injection.