Abstract
We report a rare complication of ventriculoperitoneal (VP) shunt malfunction: an intraparenchymal pericatheter cerebrospinal fluid (CSF) cyst. To the best of our knowledge, this is the second reported case of VP-shunt-related parenchymal CSF cyst to be reported in an adult patient, and the longest reported delay in development of this complication after shunt placement. Mass effect and edema from CSF cysts on CT and even T2 FLAIR sequences suggest the diagnosis of cerebral abscess or tumor. Comprehensive MR imaging can exclude both, and lead to proper management. While this complication is rare, clinicians treating adult patients with shunts, even shunts placed decades prior, need to be aware of it.