CCA likely results from malignant transformation of cholangiocytes, although transformation of epithelial cells within peribiliary glands and/or biliary stem cells may also contribute to its development. There is also evidence that subsets of CCA and mixed hepatocellular carcinoma/CCA originate from hepatic stem/progenitor cells.28,29 Etiologic and experimental evidence implicates inflammation and cholestasis as key factors in the pathogenesis of CCA