Intrahepatic Peripheral Cholangiocarcinoma:Dynamic Contrast-enhanced CT and Histopathologic Findings

Objective To study the characteristics of imaging features of intrahepatic peripheral cholangiocarcinoma (IHPCC) on the dynamic contrast-enhanced CT and correlate these features with histopathologic findings.Methods 25 cases with pathologically proven IHPCC were reviewed retrospectively.All 25 cases underwent unenhanced and triphasic dynamic contrast-enhanced CT of the abdomen.Results The location of lesions was 17 lesions (76%) in left lobe and 8 lesions (24%) in right lobe.According to pathological type,the imaging type of tumors were mass-type 15 cases (60%),infiltrative-type 5 cases (20%) and intracavitary-type 3 cases (12%).In 3 patients (12%) the tumors were not definable at any imaging phase.The shape of tumor was circular,lobulated,irregular.No contrast or mild contrast enhancement was observed in early phase and patchy,seperated or homogeneous enhancement in the central regions in the delayed phase of dynamic enhancement.The tumor was consisted of fibrous tissue,tumor cells and coagulative necrosis at the findings of histopathologic analysis.At the edge of tumor,the main components was living tumor cell that was the pathological base of early contrast enhancement.The delay contrast enhancement tended to be fibrosis,that mainly situated in the tumor central.Conclusion Dynamic contrast-enhanced CT was very important techniques for the correctly diagnosis of IHPCC.It is a typical feature of IHPCC that hypodensity of hepatic lesion on precontrast scan imaging,peripheral enhancement in the early stage and tumor central delayed contrast enhancement on the dynamic contrast-enhanced CT.