Clinical study of choledochocele: is it a risk factor for biliary malignancies?

Background. We aimed to clarify the clinical characteristics of choledochocele and to evaluate the possibility of choledochocele as a risk factor for biliary malignancies. Methods. The clinical feature, the configuration of the pancreatobiliary ductal system, coexistent pancreatobiliary lesions, and amylase level in bile in 21 patients with choledochocele were reviewed. The correlation between the configuration, comorbid diseases, and amylase level in the bile was investigated. Results. There was a female predominance, and 57% of the patients showed abdominal pain. Quite a few patients showed elevation of the levels of hepatobiliary enzymes. The configuration of the pancreatobiliary ductal system and choledochocele was classified into two categories: type 1, where the choledochocele and pancreatic duct were visualized independently or simultaneously (90.5%); and type II, where the pancreatic duct was visualized after filling of the choledochocele (9.5%). Among coexistent biliopancreatic diseases, billary stone diseases were the most frequent. Biliary malignancy was seen in 3 patients (14.3%). The amylase level in the bile was high in 50% (4/8) of the patients examined. The rate of abnormal elevation of amylase level in the bile in the two types of pancreatobiliary ductal system and choledochocele was 3/7 and 1/1, respectively. Conclusions. The prevalence of organic abnormal arrangement of the pancreatobiliary ductal system in which the choledochocele serves as a common channel is low. However, there are patients with suspected functional abnormal arrangement of the pancreatobillary ductal system, who may possibly be a high-risk group for biliary malignancy.