Endoscopic ventriculo-cystomy for non-communicating hydrocephalus secondary to quadrigeminal cistern arachnoid cyst.

INTRODUCTION: Intracranial arachnoid cysts are developmental, anomalous collections of cerebrospinal fluid (CSF), and occasionally cause symptoms when large enough to obliterate the CSF outflow pathway and give rise to non-communicating hydrocephalus. The treatment of choice for symptomatic arachnoid cysts has been surgical excision or fenestration of the cyst, but less invasive endoscopic fenestration has been attempted with favorable preliminary results. CASE REPORT: We report a case of non-communicating hydrocephalus caused by a quadrigeminal cistern arachnoid cyst in a 35-year-old woman who presented with worsening headaches. She was successfully treated by endoscopic third ventriculostomy and fenestration of the cyst (ventriculo-cistomy). DISCUSSION: Endoscopic fenestration of symptomatic arachnoid cysts can be as effective as open surgery in terms of short-term efficacy, and it is certainly less invasive than open surgery. However, its long-term outcome remains unknown, and these rare cases require careful clinical and radiological follow-up.