Epidermoid cysts in the central nervous system of mice

Two epidermoid cysts are described in mice, one intracranial, in the fourth ventricle and the other in the thoracic spinal canal. They were lined by compressed squamous epithelium and contained keratinaceous squamae. These incidental findings suggest that such cysts might be detected more often if more extensive examinations of the CNS were carried out in group studies.