Abstract
Congenital choledochal cyst is often associated with biliary tract carcinoma. Reflux of pancreatic juice into the biliary tract due to anomalous choledocho-pancreatic ductal junction usually accompanied by congenital choledochal cyst may be responsible for malignant transformation of biliary epithelia. To elucidate the mechanism of the biliary tract carcinogenicity, investigation of mutagenicity of biliary tract contents and fluorocytometric analysis of DNA content of biliary epithelia were performed. Mutagenicity of biliary tract contents was confirmed in 6 among 12cases of congenital choledochal cyst with anomalous choledochopancreatic ductal junction.
The DNA histogram showed high incidence of DNA-aneuploidy in 2 among 4 cases examined: moreover, the 2 cases revealed marked biliary epithelial proliferative changes.
It is suggested that biliary tract contents mixed with pancreatic juice in the environment of anomalous choledocho-pancreatic ductal junction contain mutagenic substances, and that the biliary epithelia receive not only atypical changes but also DNA-aneuploidy in the environment.
