Bilothorax as an endoscopic retrograde cholangiopancreatography complication and a review of the literature.

Bilothorax, the accumulation of bile in the pleural space, is an uncommon but serious condition often linked to biliary tract or diaphragmatic injury. This case report describes a 70-year-old female with decompensated liver cirrhosis due to primary sclerosing cholangitis, who developed a moderate sized pleural effusion following ERCP and biliary stenting. The patient's pleural effusion persisted for 2 months without respiratory symptoms, indicating a self-limited low-volume leak. She eventually underwent thoracentesis for a non-resolving unilateral effusion, which drained 435 mL of bilious fluid with an elevated pleural fluid bilirubin level, confirming the diagnosis of bilothorax. This case highlights the importance of considering bilothorax as a cause of pleural effusion in patients with biliary tract disease and who undergo high risk procedures including ERCP.