Intra-fourth ventricular arachnoid cyst: The case for a direct surgical approach

Abstract

Abstract Arachnoid cysts (ACs) are benign, extra-axial, developmental cysts derived from the arachnoid membrane. These cysts often develop in the cisternal spaces and rarely involve the fourth ventricle. When they do, their differential diagnosis can be challenging. Although their surgical treatment has to be proactive, there appears to be a lack of consensus regarding the best surgical strategy. Here we report a 16-year-old boy with hydrocephalus and ataxia in the setting of a fourth ventricular AC. A direct surgical approach through a midline suboccipital corridor enabled us to sub totally resect the cyst and establish the cerebrospinal fluid (CSF) pathway. The child had an uneventful recovery and continues to be asymptomatic at 1-year follow-up. We conclude that a direct approach to the cyst appears to be a reasonable treatment choice and primary CSF diversion rarely helps in these situations. We present a literature review and a management algorithm.