Introduction: Cerebrospinal fluid (CSF) hydrothorax is a rare but potentially critical cause of respiratory distress in pediatric patients with ventriculoperitoneal (VP) shunts. When unrecognized, this can lead to repeated invasive procedures, such as thoracentesis and intubation, and delayed diagnosis. Timely identification and use of specific biomarkers such as beta-2 transferrin are essential to confirm the presence of CSF in pleural space and guide appropriate management.
Description: We report the case of an 8-year-old male with a history of communicating hydrocephalus due to posterior fossa arachnoid cyst, with VP shunt placement, who presented with respiratory failure and a large right-sided pleural effusion. A pigtail catheter was placed with approximately 700 mL of clear and colorless fluid rapidly drained. Due to concern for CSF leakage, the thoracostomy tube was clamped, and a chest X-ray was obtained to ensure it was not draining the VP shunt directly. Once correct placement was confirmed, pleural fluid was sent for analysis, and the tube was placed to suction. Chest CT, post drain placement, revealed residual moderate right-sided pleural effusion, scattered ground-glass opacities, and abdominal ascites exceeding expected levels for a VP shunt, suggesting CSF malabsorption in the peritoneum. Beta-2 transferrin was ultimately detected in the pleural fluid, confirming the presence of CSF in the pleural fluid. The patient was managed with supportive care, short-term acetazolamide, and chest tube drainage. He recovered without further intervention and was discharged at baseline with neurosurgical follow-up.
Discussion: This case illustrates a rare presentation of pleural effusion of extra-vascular origin involving CSF migration into the pleural space, likely through a small diaphragmatic defect, in the setting of VP shunt failure or peritoneal absorption dysfunction. CSF hydrothorax is an underrecognized cause of respiratory compromise in patients with VP shunts. Thus, a high index of suspicion, careful fluid analysis, and confirmatory beta-2 transferrin testing is essential for prompt diagnosis. Multidisciplinary management, including neurosurgery and critical care, is key to successful treatment and improved long-term outcomes.
