Tumors of the gallbladder and bile ducts.

Gallbladder cancer is the fifth most common gastrointestinal cancer in the US (5,000 new cases each year). Primary bile duct cancer (cholangiocarcinoma) is seen most often in patients with risk factors including primary sclerosing cholangitis (PSC), bile duct stones, and fluke infestation. Both cancers have a poor prognosis, in part because they present late. Malignant tumors of the gallbladder and bile ducts are rarely curable by surgery. Benign tumors of the biliary tree are rare, and with the exception of biliary papillomatosis and carcinoids, are not considered premalignant.