Complex Pleural Effusion Associated With a Subphrenic Gallstone Phlegmon Following Laparoscopic Cholecystectomy

A 90-year-old man presented with a large right-sided complex pleural effusion 4 months after a laparoscopic cholecystectomy. An initial thoracic CT scan confirmed the presence of the effusion, and the results of thoracentesis on three separate occasions were consistent with an exudative process. Another CT scan of the chest with thin-section cuts through the diaphragm along with an abdominal ultrasound revealed a retrohepatic subdiaphragmatic gallstone collection that eroded into the right hemidiaphragm. Thoracoscopic evacuation of the phlegmon, removal of the spilled gallstones, and repair of the diaphragm resulted in resolution of the effusion.