Factors of biliary carcinogenesis in choledochal cysts

The long-term complications of choledochal cysts include malignant degenera tion of the epithelial lining of the biliary tract. Possible factors leadin g to malignant degeneration were examined by measuring amylase levels in th e biliary tract, intraoperative biliary manometry and a histopathological s tudy. 27 patients, 1 to 13 years of age, with choledochal cysts, were studied ove r a 13-year period. Amylase levels in the bile of choledochal cysts and the gallbladder were measured. The pressure profile of the biliary tract was r ecorded as the probe was withdrawn from the sphincter of Oddi (SO) to the d istal end of the common bile duct, Hyperplasia of the gallbladder mucosa an d malignancy of the biliary tract were investigated. Patients with high levels of biliary amylase had higher pressure difference s between the SO and the duodenum than those with low levels of biliary amy lase. The incidence of mucosal hyperplasia of the gallbladder mucosa was si gnificantly higher in the fusiform type than in the cystic type. Adenocarci noma in a cystic choledochal dilatation was found in a 12-year-old girl wit h high amylase levels. The cause of regurgitation of pancreatic juice into the biliary system migh t be due to a high pressure difference between the SO and the duodenum in a ddition to the lack of sphincter function at the abnormal junction of the p ancreaticobiliary ductal system. Early diagnosis and surgical treatment to prevent the regurgitation leading to hyperplasia and malignancy of the bili ary tract are important for children with choledochal cysts.