Cholangiocarcinoma (CCA) is a very heterogeneous cancer from any point of view, including epidemiology, risk factors, morphology, pathology, molecular pathology, modalities of growth and clinical features. Given this heterogeneity, a uniform classification respecting the epidemiologic, pathologic and clinical needs is currently lacking. In this manuscript we discussed the different proposed classifications of CCA in relation with recent advances in pathophysiology and biology of this cancer.
Keywords: Cholangiocarcinoma (CCA); biliary cancerogenesis; biliary tree stem/progenitor cells; cells of origin; extra-hepatic CCA; hepatic stem/progenitor cells; intra-hepatic CCA.