Intrahepatic biliary cystadenoma： Is there really an almost exclusively female predominance

Biliary cystic tumors, such as cystadenomas and cyst- adenocarcinomas, are rare cystic tumors of the liver, accounting for less than 5% of all intrahepatic cysts of biliary origin. Biliary cystadenomas have been known to occur predominantly in women （〉 85%）, and 38%-44% of biliary cystadenocarcinomas have occurred in males. We wrote this letter to comment on a brief article （World J Gasteroenterol 2011 January 21; 17（3）： 361-365） regarding a case of intrahepatic biliary cystic neoplasm treated with surgery. The adenoma-carcinoma sequence is the possible mechanism of carcinogenesis. If the carcinogenesis of biliary cystadenocarcinoma occurs in the adenoma-carcinoma sequence, we believe that the male-to-female ratio of cystadenoma should be higher than the incidence rate that has been reported to date.