Pathology and cellular kinetics of gallbladder with an anomalous junction of the pancreaticobiliary duct.

Objectives : Anomalous junction of the pancreaticobiliary duct (AJPBD) is thought to be an important risk factor for gallbladder carcinoma in Japan. In this report, we examine histopathology and cellular kinetics of gallbladder mucosae of patients with AJPBD and the possible risk of gallbladder carcinoma. Methods : We examined 62 gallbladders from patients with AJPBD (group A), 16 gallbladder carcinomas from patients with AJPBD (group B), 60 gallbladder carcinomas from patients without AJPBD (group C), and six normal gallbladders from patients without AJPBD (group D). Histopathology, mucosal heights, and proliferative cell nuclear antigen-labeling index were obtained from routinely processed tissue specimens. Results : The incidence of hyperplastic changes in group A and in the noncancerous regions (NCRs) of group B was greater than in the NCRs of group C (p < 0.05). The incidence of dysplastic changes in the NCRs of group B was greater than in the NCRs of group C (p < 0.05). The mucosal heights in group A and in the NCRs of group B were higher than in the NCRs of group C (p < 0.05). A high proliferative cell nuclear antigen-labeling index was observed in group A and in the NCRs of group B, where hyperplastic changes were frequently observed. Conclusions: These results suggest that a sequence of hyperplastic changes with a corresponding increase in cellular kinetics with progression through dysplasia to carcinoma may be important in carcinogenesis in gallbladders of patients with AJPBD. AJPBD itself may be a possible risk for gallbladder carcinoma.