[Vermian epidermoid cyst revealed by head injury]

Vermian epidermoid cyst developing in the fourth ventricle is very rare. We report a case observed in a 24-year-old man, who presented severe headache, dizziness and a blurred vision following head injury. Examination revealed a discrete gait disturbance. Cerebral CT-scan showed a large hypodense lesion of the posterior fossa without contrast enhancement. MRI demonstrated the vermian location of this lesion which displaced the roof of the fourth ventricle upward and the brainstem forward. A suboccipital approach allowed total removal of a well-encapsulated epidermoid cyst, non adherent to the floor of the fourth ventricle. The postoperative course was uneventful.