EUS diagnosis of ectopic opening of the common bile duct in the duodenal bulb: a case report.

Among the various congenital anomalies of the biliary system, an ectopic opening of the common bile duct (CBD) in the duodenal bulb is extremely rare. ERCP is essential for diagnosing the anomaly. A 55-year-old male was admitted to hospital for severe right upper quadrant abdominal pain, followed by fever, chills, elevated body temperature and mild icterus. The diagnosis of ectopic opening of CBD in the duodenal bulb was established on endoscopic ultrasonography (EUS), which clearly demonstrated dilated CBD, with multiple stones and air in the lumen, draining into the bulb. A normal pancreatic duct, which did not drain into the bulb, was also observed. This finding was confirmed on ERCP and surgery. As far as we know, this is the first case of this anomaly diagnosed by EUS. Ectopic opening of the CBD in the duodenal bulb is not an incidental finding, but a pathologic condition which can be associated with clinical entities such as recurrent or intractable duodenal ulcer, recurrent biliary pain, choledocholithiasis or acute cholangitis. Endoscopic ultrasonography features allow preoperative diagnosis of this anomaly and can replace ERCP as a first diagnostic tool in such clinical circumstances. Embryology of the anomalies of the extrahepatic biliary tree has been also reviewed.