Biliary Tract and Primary Liver Tumors: Who, What, and Why?

Biliary tract and primary liver tumors can be divided into intrahepatic and extrahepatic sites. Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma are the most common primary liver malignancies, making up 75% and 15% of cases, respectively. In the United States, there has been an increase in incidence of HCC and cholangiocarcinoma over the last 2 decades, and it is probable that the incidence of both will continue to climb. Gallbladder cancer, however, is the most frequent biliary tract cancer, comprising 80% to 90% of biliary tract cancers worldwide. Underlying epidemiology and cause are discussed.