Cerebrospinal fluid pseudocyst presenting as ascites: A case report.

BACKGROUND: Cerebrospinal fluid (CSF) pseudocysts are uncommon complications of ventriculoperitoneal (VP) shunts, usually occurring within 3 weeks to 10 years of insertion. We report a perihepatic CSF pseudocyst presenting over 27 years after shunt placement, representing an exceptionally long interval compared with prior reports. This case highlights the importance of maintaining diagnostic openness when investigating unexplained ascites, and demonstrates the role of fluid beta-2 transferrin in confirming a rare diagnosis.

CASE SUMMARY: A 42-year-old man with spina bifida and prior VP shunt insertion was admitted for urinary tract infection, later developing recurrent symptomatic perihepatic fluid collections. Extensive hepatic, cardiac, and surgical evaluations were unremarkable, and repeated percutaneous drainages failed. The possibility of CSF origin was raised after clinical reappraisal, and beta-2 transferrin testing of the drained fluid confirmed a CSF pseudocyst. The patient underwent VP shunt exploration and revision with relocation to the pleural space, leading to resolution of the abdominal collections and symptoms.

CONCLUSION: Persistent diagnostic uncertainty requires broad clinical suspicion and selective testing to identify rare causes of ascites.