[Late disclosure of intra-cerebral epidermoid cyst].

Symptoms of right hemisphere dysfunction had developed over a 10-month period in a 69-year old woman. She had experienced transient episodes of facial asymmetry for 10 years. CT scan showed a hypodense hourglass tumor extending above and below the tentorium. MRI showed a low-intensity signal with T1-weighted sequences and a high-intensity signal with T2-weighted sequences. The tumour was removed. Pathological examination proved the tumor to be an epidermoid cyst. Such a tumor may have been responsible for transient deficits in the late stages of development.