Epidermoid tumors involving the fourth ventricle.

The case histories of three patients with epidermoid tumors of the 4th ventricle treated by surgical excision are presented. All three cases exhibited a prolonged latent period from the onset of symptoms to the final diagnosis. Despite the strategic location and enormous size of all three tumors, only one of the patients had significant hydrocephalus. The radiographic diagnosis and differential diagnosis of epidermoid tumors are discussed.