Bilothorax
A 77-year-old man with metastatic lung adenocarcinoma presented to the emergency department with a 2-week history of dyspnea. Examination was notable for reduced breath sounds at the right lung base. A chest radiograph showed a pleural effusion on the right side (Panel A). An abdominal ultrasound image showed previously known liver metastases and perihepatic fluid, as well as new intrahepatic dilatation of the biliary ducts. Laboratory studies showed a serum total bilirubin level of 2.5 mg per deciliter (42.8 μmol per liter) (reference range, 0.3 to 1.2 mg per deciliter [5.1 to 20.5 μmol per liter]) and a direct bilirubin level of 2.0 mg per deciliter (34.2 μmol per liter) (reference range, 0.03 to 0.4 mg per deciliter [0.5 to 6.8 μmol per liter]). A chest tube was placed, and the color of the drained pleural fluid was olive brown that gradually changed to black (Panel B). Pleural-fluid studies showed an exudate with a total bilirubin level of 8.2 mg per deciliter (140.2 μmol per liter; reference value, 0) and a direct bilirubin level of 7.5 mg per deciliter (128.2 μmol per liter; reference value, 0). The pleural-fluid triglyceride level was normal, and cultures and cytologic studies were negative. A diagnosis of bilothorax was made. Bilothorax occurs when bile flows into the pleural space. In this case, the mechanism was thought to be diaphragmatic defects caused by hepatic metastases. Two weeks after presentation, the patient died from progressive liver failure.