Abstract
A 63-year-old male presented with a rare epithelial cyst in the left cerebellopontine angle manifesting as left facial nerve paresis and left cerebellar signs. Computed tomography revealed a well-defined cystic mass of homogeneous low density with no enhancement. Magnetic resonance imaging also demonstrated a cystic mass appearing as low intensity on T1-weighted images and high intensity on T2-weighted images. The cyst content was clear fluid. The cyst wall consisted of nonciliated, columnar epithelial cells, showing a pseudostratified arrangement in focal areas. Positive staining by periodic acid-Schiff, Alcian blue, and carcinoembryonic antigen suggested that the cyst was an enterogenous cyst of endodermal origin. Cysts in this location often cause cranial nerve impairment, but the symptoms are usually resolved by surgical treatment.
