A proposal of imaging classification of intrahepatic mass-forming cholangiocarcinoma into ductal and parenchymal types: clinicopathologic significance.

• We propose subclassification of mass-forming intrahepatic cholangiocarcinoma (MF-iCCA) as parenchymal and ductal types, on the basis of magnetic resonance imaging findings of biliary abnormality. • Two types of MF-iCCAs exhibit different clinical and histopathological characteristics and post-surgical outcomes.