Choledochoduodenal fistula at the anterior wall of the duodenal bulb: a rare complication of duodenal ulcer.

A 38 year-old man was admitted to our hospital with the chief complaint of epigastralgia. His laboratory data revealed leukocytosis and increased serum amylase, and abdominal ultrasonography revealed diffuse swelling of the pancreas. Thus, he was diagnosed as having acute pancreatitis. Moreover, abdominal computed tomography showed pneumobilia in the gallbladder and the common bile duct. Gastroduodenal fiberscopy demonstrated peptic ulcer scars around a foramen with smooth margins at the anterior wall of the duodenal bulb. The bile juice flowed from the bottom of the foramen. Endoscopic retrograde cholangiopancreatography revealed the fistula between the common bile duct and the anterior wall of the duodenal bulb, but not the posterior wall. However, there was no pancreatico-biliary maljunction and no stones in the gallbladder or bile duct. This is a rare case of choledochoduodenal fistula at the anterior wall of the duodenal bulb caused by duodenal peptic ulcer disease.