Epidermoids of the fourth ventricle.
D000328:Adult; D002551:Cerebral Ventricle Neoplasms / Q000000981:diagnostic imaging*; D014695:Cerebral Ventriculography; D002781:Cholesteatoma / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged