Diffusion-weighted MR imaging (DWI) in two intradural spinal epidermoid cysts

Epidermoid cysts are rare, benign, congenital, slow-growing inclusion cysts. On T1 and T2 weighted NMR images epidermoid cysts show heterogeneity and lack of contrast enhancement. Based on signal intensities on conventional sequences, epidermoid cysts cannot be distinguished from other neoplastic lesions. When located in the spinal cord, differential diagnosis includes ependymoma, astrocytoma, cavernoma and metastasis. Diffusion-weighted imaging (DWI) has been shown to accurately distinguish intracranial epidermoid tumors from arachnoid cysts. DWI findings in two patients with surgically proven epidermoid cysts in the spinal canal are reported.