Pathological features and surgical outcome of pancreaticobiliary maljunction without dilatation of the extrahepatic bile duct.

In cases of pancreaticobiliary maljunction without dilatation of the extrahepatic bile duct (undilated PBM), preventive cholecystectomy is performed because there is a high incidence of gallbladder cancer as compared to cases of PBM with dilatation of the extrahepatic bile duct (dilated PBM). However, it is still controversial whether resection of the extrahepatic bile duct should also be performed in patients with undilated PBM. Accordingly, we analyzed pathological findings, postoperative complications and a long-term prognosis in 19 patients with undilated PBM to clarify the possibility of the bile duct cancer. In undilated PBM, hyperplasia was significantly recognized in the gallbladder as compared to the bile duct (p=0.0238), while no significant differences were found in other epithelium. Atypical epithelium and hyperplasia in gallbladder mucosa of undilated PBM were significantly recognized as compared to cases of pancreas or biliary tract cancer without PBM (p=0.0035, p=0.0019, respectively), while no significant differences were recognized in any kind of epithelium of the bile duct. In 14 cases of undilated PBM with preservation of the extrahepatic bile duct, the postoperative observation period was from 1 year and 5 months to 18 years and 10 months (mean: 8.3 years). One of the 5 patients with gallbladder cancer died 2 years and 6 months after surgery due to the cancer recurrence, while the remaining 13 patients had no complications such as liver dysfunction, cholangitis or remnant bile duct cancer, and the patients have survived in good health. These findings indicate that preventive bile duct resection is not necessary in patients with undilated PBM.