Intracranial epidermoid cysts in three dogs.

Intracranial epidermoid cysts were identified within the fourth ventricle of three dogs. The cysts measured up to 2.5 cm in diameter, were lined by stratified squamous epithelium, and contained intraluminal keratinaceous debris. Secondary compression of the medulla oblongata and cerebellum caused neurologic dysfunction in two dogs; the cysts was an incidental finding in the other dog. Similarities between these dogs and three previously reported intracranial epidermoid cysts in dogs included an apparent predilection for young dogs and involvement of the cerebellopontine angle, fourth ventricle, or both.