<prompt> The following are risk factors for developing cholangiocarcinoma except -Choledochal cystCholelithiasisLiver flukesWorking in the rubber industry  <response>: Cholangiocarcinoma CCA is an uncommon tumour that can arise anywhere in the biliary tree, from the intrahepatic bile ducts 20-25 of cases and the confluence of the right and left hepatic ducts at the liver hilum 50-60 to the distal common bile duct 20. It accounts for only 1.5 of all cancers but the incidence is increasing. The cause is unknown but thetumour is associated with gallstones, primary and secondary sclerosing cholangitis, Carolis disease and choledochal cysts . ref Harrison 20th edition pg 567 