Background: Except for pancreaticobiliary maljunction, the relationship between a relatively long common channel and gallbladder carcinoma is unknown.
Methods: For purposes of this study, a high confluence of pancreaticobiliary ducts was defined as a common channel that is 6 mm or greater in length, together with occlusion of the communication between the pancreatic and bile ducts during sphincter contraction. Pancreaticobiliary maljunction and high confluence of the pancreaticobiliary ducts were detected in 69 (2.1%) and 54 (1.6%), respectively, of 3300 consecutive patients who underwent ERCP. Proliferation activity and genetic alteration were examined in the non-carcinomatous epithelium of the gallbladder in patients with these two radiographic findings at ERCP.
Results: The Ki-67 labeling index in the epithelium in cases of a high confluence of the pancreaticobiliary ducts and pancreaticobiliary maljunction without biliary dilatation was significantly greater than that in cases of gallbladder carcinoma without these anomalies (p < 0.01). Overexpression of p53 and K-ras mutations were detected in, respectively, 22.2% and 27.8% of cases of a high confluence of pancreaticobiliary ducts.
Conclusions: A relatively long common channel may be an important risk factor for the development of gallbladder carcinoma. Vigilance for the development of gallbladder carcinoma is indicated in patients with a relatively long common channel, in addition to those with pancreaticobiliary maljunction.