Spectrum of Biliary and Nonbiliary Neoplasms Growing and Spreading Within the Lumen of the Bile Ducts

In the hepatobiliary system, the majority of neoplasms grow within the hepatic parenchyma; however, some arise, grow, and/or spread within the lumen of the intrahepatic large bile ducts and the perihilar/distal bile ducts (collectively referred to as large bile ducts), representing specialized ductal organs associated with unique peribiliary glands and being distinct from the intrahepatic small bile ducts and bile ductules embedded within the hepatic parenchyma. Precursors of cholangiocarcinoma