Dynamic CT findings of cholangiolocellular carcinoma: correlation with angiography-assisted CT and histopathology.

OBJECTIVES: To elucidate the dynamic CT features of pure type of cholangiolocellular carcinoma (pure CoCC) in comparison with those of cholangiocellular carcinoma (CCC) and to analyze their bases by angiography-assisted CT with histopathologic correlation.

METHODS: Surgically confirmed 10 pure CoCCs, 10 CCCs and 7 mixed CoCC and CCCs from August 2001 to May 2012 were included in this study. Among them, dynamic CT features were compared. In 8 pure CoCCs, the correlative study between angiography-assisted CT and histopathological study was performed to clarify the basic mechanism of dynamic CT features.

RESULTS: All pure CoCCs showed early and prolonged enhancement homogeneously or inhomogeneously and 8 of 10 pure CoCCs showed early peritumoral enhancement on dynamic CT. Time-attenuation curve provided by dynamic CT showed significant higher Hounsfield unit value of pure CoCC than those of CCC at each phases (p < 0.05). The depiction of peritumoral enhancement in CoCC was nearly simultaneous to tumor stain on dynamic CT during hepatic arteriography. Pathologic analysis revealed there were abundant communications between blood sinusoids of the tumor and intra and peritumoral portal venules and surrounding hepatic sinusoids.

CONCLUSION: Early tumoral staining and peritumoral enhancement due to early drainage from the tumor and prolonged enhancement are characteristic findings in pure CoCCs.