https://www.aasld.org/liver-fellow-network/core-series/why-series/why-do-we-transplant-some-types-cholangiocarcinoma-and
Cholangiocarcinoma (CCA) represents a heterogeneous group of malignancies arising from the biliary epithelium. It is divided into three subtypes depending on their anatomical site of origin:
intrahepatic (iCCA),
perihilar (pCCA) and
distal (dCCA).
iCCAs arise above the second-order bile ducts, while pCCA (also called a Klatskin tumor) arise above the cystic duct with dCCA coming from below the cystic duct.
pCCA is the single largest group, accounting for approximately 50–60% of all CCAs, followed by dCCA (20–30%) and iCCA (10–20%).
In this post, we will primarily discuss pCCA and iCCA, as dCCA is treated surgically with pancreaticoduodenectomy (Whipple procedure) rather than liver transplantation.
CCA accounts for approximately 3% of all gastrointestinal cancers representing the second most common primary hepatic malignancy after hepatocellular carcinoma (HCC).
Unlike HCC, the majority of CCA cases occur in the absence of an evident chronic liver disease or other risk factor making it more difficult to catch early.
Primary risk factors are Primary Sclerosing Cholangitis (PSC), with a lifetime risk of 10%, rising to 30% in those with Inflammatory Bowel Disease (which is why we annually screen these patients with an MRI), biliary cystic disease, and less commonly hepatitis B. Outside of the United States, southeast Asian liver flukes remain a risk factor.