Epidemiology and risk factors of biliary tract and primary liver tumors.

Primary liver and biliary tract tumors encompass a range of benign and malignant neoplasms. They consist of histologically distinct types of tumors that arise from and are influenced by hepatocytes, biliary epithelial cells, and mesenchymal cells. Improvements in imaging have allowed the detection and diagnosis of these neoplasms to be refined. Investigation at the histologic, molecular, and genetic levels has allowed neoplasms to be categorized and treated. Epidemiology has improved understanding of geographic, ethnic, gender, and cultural differences that link exposures with cancer risk. This article focuses on the epidemiology of major primary adult liver and biliary tract tumors.