[Sub-callus epidermoid cyst. A case report].

The cranio-encephalic epidermoid cysts are rare tumors. These lesions are extra-axial and can occur at the infratentorial or supratentorial level. The epidermoid cysts are classically in contact with the base of the skull, and less often intraventricular; the other locations are exceptional. Because of their CT aspect (hypodense lesion, rarely isodense, well defined, without contrast enhancement, and without surrounding edema) and MR aspect (in more than 70% of the cases: more or less homogeneous lesion, hypointense in T1 and hyperintense in T2), the authors believe that it is possible to suggest such a diagnosis even with an atypically located case. We report the case of an epidermoid cyst located between the corpus callosum and the falx cerebri.