Spontaneous retroperitoneal biloma: a case report.

We report a rare case of spontaneous rupture of the biliary tree with biloma in the retroperitoneum. A 74-year-old man was admitted with back pain and general weakness. Computerized tomography (CT) and sonography showed a huge lesion in the right retroperitoneum, and a diagnosis of biloma was made after percutaneous aspiration. A percutaneous drainage catheter was initially inserted into the right retroperitoneal lesion under sonographic guidance to treat the biloma because of high surgical risk. When his general condition had improved, the patient underwent cholecystectomy and removal of the common bile duct stone; there was no evidence of leakage in the extrahepatic bile duct. Non-surgical intervention before definitive biliary surgery is considered the first choice for treating bilomas in high-risk patients.