Atypical epidermoid cyst with repetitive hemorrhages in the supracallosal region: case report.

A 63-year-old man presented with an unusual supracallosal epidermoid cyst with repetitive hemorrhages that initially manifested as severe headache in 2003. Physical examination found no neurological deficit. Computed tomography demonstrated a homogeneously high density mass lesion measuring 3 x 3 cm in the supracallosal area, and the clinical diagnosis was cavernous malformation. No change occurred in neurological findings except for headache, but the lesion underwent hemorrhages several times over a 4-year period and increased in size to 4 x 5 cm. Surgery revealed a pearly cyst filled with old blood and debris. Histological examination disclosed keratinizing, stratified squamous epithelium without hair follicles or sebaceous glands, consistent with the diagnosis of epidermoid cyst. Surgery was successfully performed without complications such as akinetic mutism, motor weakness, or chemical meningitis. The present case suggests that epidermoid cyst should be considered in the differential diagnosis of suspected cavernous malformation in any location.