[Interhemispheric epidermoid cyst. A clinical case].

The authors report a rare case of epidermoid cyst with interhemispheric growth closely connected to the anterior portion of the corpus callosum. Although extremely sensitive in determining the site, dimensions and relations of the lesion, NMR does not allow the nature of this pathology to be diagnosed owing to the lack of signal specificity. CT, using the measurement of Hounsfield units, allows a differential diagnosis of epidermoid cysts and arachnoid cysts and lipomas to be made in almost all cases. Treatment is surgical and the complete excision of the capsule avoids recidivation.