Carcinoma arising in choledochocele

Background and Study Aims: Choledochocele has a potential for carcinogenesi s, but no report has described malignant changes of the choledochocele in r elation to pancreaticobiliary reflux because its anatomic form does not fit the criteria of pancreaticobiliary malunion (PBM), The aims of this study were to analyze the amylase level in bile in patients with choledochocele a nd to clarify whether the presence of a choledochocele predisposed to carci noma. Patients and Methods: Records of 2826 patients who had undergone endoscopic retrograde cholangiopancreatography between 1995 and 1999 were reviewed fo r the presence of choledochocele and/or periampullary carcinoma. As an evid ence of pancreaticobiliary reflux, amylase activity was examined in common duct bile obtained at surgery or by endoscopy, The prevalence of periampull ary carcinoma was compared between patients with and without choledochocele . Results: A total of 11 patients were diagnosed as having a choledochocele. The amylase level in bile was higher in patients with choledochocele (120 9 22+/-62 269 IU/l; n = 4) than in previously examined patients with function ing gallbladders (15 +/- 24 IU/l n=10, P=0.005). The prevalence of periampu llary carcinoma In patients with choledochocele (27%, 3/11) was significant ly higher than that in those without choledochocele (0.9%, 26/ 2815; P<0.00 02). Conclusion: The bile analysis of the present study presents one possible ex planation for the predisposition to carcinoma in choledochocele as bile con taining amylase may stagnate in the choledochocele and then carcinoma may d evelop in the inner epithelium of the choledochocele by the same mechanism as that leading to carcinogenesis in patients with PBM.