Abstract: | A 44-year-old woman had occasional headaches and dysfunction of the facial and trigeminal nerves on the left side as well as ataxia. These clinical manifestations disappeared after removal from the left cerebellopontine angle of a 3 × 4.5 × 5-cm prealbumin-positive cyst of the choroid plexus epithelium, a type of neuroepithelial cyst. A review of 57 reported cases of neuroepithelial cysts in the posterior cranial fossa disclosed 32 symptomatic cysts (56%) and 25 symptomless cysts (44%). The recorded age of 35 patients ranged from 5.5 months to 65 years with the average age of 30 years for both genders; 14% of patients were less than 1-year-old. The ratio of males and females was 1:1. The cysts were located at the following sites: fourth ventricle (51%); intraneural substance as in cerebellar vermis, pons and mesencephalon (7%), and posterior cranial fossa proper (42%) especially in the cerebellopontine angle (18%). The pathogenesis of these cysts is proposed to be related to developmental anomaly of the neuroepithelium which also includes the ectopic neuroepithelial elements. Surgical extirpation of the cyst is the treatment of choice. Total resection should be attempted if it is feasible depending on where the cyst is situated. Fenestrating the cyst wall is also a useful surgical procedure in order to allow communication between the cyst contents and the pathway of the cerebrospinal fluid for abolishing the increased intracranial pressure. |