Cholangiocarcinoma: Clinical manifestations and diagnosis

Cholangiocarcinoma (CCA) is the most common malignancy of the biliary tract. CCA is most commonly present with perihilar tumor location, the so-called “Klatskin tumor.” However, mass-forming CCAs can also occur. The most important mimicker of CCA is IgG4-associated cholangiopathy, which can create strictures radiologically resembling CCA. Long-standing inflammatory processes in the liver and biliary tree may be involved in biliary carcinogenesis. Liver fluke infestation and oriental cholangiohepatitis are seen primarily in Asia, and increase the risk of CCA. Primary sclerosing cholangitis (PSC) is a risk factor for CCA; CCA in patients with primary sclerosing cholangitis presents 1-2 decades earlier than sporadic CCA cases. Choledochal cysts and Caroli disease are also associated with a higher incidence of CCA. Perihilar CCA can be challenging to diagnose and treat. The Bismuth-Corlette anatomical classification presents an important touchstone for planning therapy. Magnetic resonance imaging and magnetic resonance cholangiopancreatography are the most important imaging tests in the evaluation of CCA; magnetic resonance cholangiopancreatography is extremely important for treatment planning, whether by surgery, endoscopic retrograde cholangiopancreatography (ERCP) stent placement, or percutaneous drainage. ERCP can sample ductal strictures to assess for malignancy. Cytologic or histologic diagnosis is critical to plan treatment, but yields from a variety of sampling methods are often disappointing. Adjunctive labaratory testing, particularly serum CA 19-9, is commonly used to aid in diagnosis. The use of fluorescent in situ hybridization may increase sensitivity and specificity of cytologic sampling. Newer imaging techniques that can be used at ERCP may play an increased role in diagnosis of CCA in the future. Endoscopic stent placement by ERCP is a standard treatment except in those rare resectable cases.