Anomalous pancreaticobiliary ductal union--an etiologic association of gallbladder cancer and adenomyomatosis.

Background/aims: Anomalous pancreaticobiliary ductal union (APBDU) has been proposed as a risk factor of gallbladder cancer. To clarify the frequency and the subtype distribution of APBDU in patients with gallbladder cancer and adenomyomatosis, a retrospective study was performed.
Methodology: The radiograms of endoscopic retrograde cholangiopancreaticography of 680 patients with well-documented biliary and pancreatic ducts from April 1992 to November 1996 were reviewed. The length of the common channel and insertion of the pancreatic duct and the bile duct were identified and recorded.
Results: Gallbladder cancer and adenomyomatosis were identified in 8 and 12 patients, respectively. Patients with gallbladder cancer were significantly older (mean age: 66.5 years, p<0.01) than those with gallbladder adenomyomatosis (mean age: 42.7 years). APBDU was noted in 59 (8.7%) of 680 cases with complete pancreaticobiliary radiograms. Among them, 5 of 8 patients with gallbladder cancer coexisted with APBDU. Four (80%) belonged to the P-B type. Six of 12 patients with gallbladder adenomyomatosis had APBDU. Five (83.3%) belonged to P-B type.
Conclusions: Patients with gallbladder cancer and adenomyomatosis were frequently associated with APBDU. The close relationship and similar distribution of the P-B type of APBDU in both diseases suggest an etiologic association in various gallbladder diseases.