Malignant potential of the gallbladder in patients with anomalous pancreaticobiliary ductal junction. The difference in risk between patients with and without choledochal cyst.

Anomalous pancreaticobiliary ductal junction (APBDJ) is considered to be a factor developing carcinoma of the biliary tract. However, the difference in clinical significance of APBDJ between patients associated with choledochal cyst and those without cyst with special reference to the malignant potential of the gallbladder has been little studied. Of 1,325 patients examined with direct cholangiography, 29 patients were found to have APBDJ of whom 21 patients were associated with choledochal cyst while eight were not. Their associated hepatobiliary diseases were clinicopathologically examined and compared. The frequencies of carcinoma of the gallbladder in patients without choledochal cyst and in those with cyst were 50% and 5%, respectively, the difference being significant (p < 0.05). This frequency did not depend upon the type of APBDJ. None of the patients with gallbladder carcinoma had gallstones. The overall frequencies of carcinoma of the biliary tract (gallbladder and bile duct) were 14% in patients with cyst and 50% in those without cyst. All were gallbladder carcinoma in the latter group. We conclude that the gallbladder is under the condition with significantly greater malignant potential in patients with APBDJ especially in cases not associated with choledochal cyst. Prophylactic cholecystectomy and excision of cyst if associated should be indicated for patients with APBDJ.