Cerebellopontine angle epithelial cyst. A case report.

A case of epithelial cyst in the cerebellopontine angle is reported. The cyst wall showed glandular epithelium with areas of non-keratinized stratified epithelium and flattened cuboidal cells. The glandular areas stained positively with antibodies to cytokeratin. In addition, the cyst wall contained areas of arachnoid tissue. This, and the unusual position of the cyst, suggest that the epithelial elements in the cyst wall may be metaplastic in origin. Similar previously described cysts were considered to be endodermal in origin.