Biliary tract malignancy and abnormal pancreaticobiliary junction in a Western population

Abnormal pancreaticobiliary junction is a rare congenital disorder in which the junction of biliary and pancreatic duct is located outside the duodenal wall and forms a long common channel. The disorder has been associated with a high incidence of gallbladder cancer in Japanese studies. The aim of this study was to assess the frequency of abnormal pancreaticobiliary junction in a Western population and its association with biliary tract malignancies.

All endoscopic retrograde cholangiopancreatography examinations of 82 consecutive patients with gallbladder carcinoma or biliary duct cancer treated at Baylor University during a period of 10 years were analyzed. A further 220 consecutive patients with normal films or non-malignant pancreaticobiliary disease acted as controls.

Fifty-eight (70.7%) patients were found to have adequate imaging of junction and were included in the analysis. These included 37 patients with common bile duct carcinoma and 21 with gallbladder carcinoma. Abnormal pancreaticobiliary junction (common channel > or =8 mm) was observed in 44.8% patients with biliary tract carcinoma compared to 6.2% of controls (P < 0.01). Eighteen had type I abnormality and eight type II. Seven patients had a cystic dilatation of the common bile duct, all with type I abnormality. Mean overall survival was 9.5 months. Survival did not differ significantly between patients with normal and abnormal junctions (P = 0.1).

The results suggest a close association between the anatomy of the distal ends of the common bile duct and main pancreatic duct and development of biliary tract carcinoma in Western populations.