Objective: To investigate the correlation between enhancement patterns of intrahepatic cholangiocarcinoma (ICC) on contrast-enhanced ultrasound (CEUS) and pathological findings.
Methods: The CEUS enhancement patterns of 40 pathologically proven ICC lesions were retrospectively analysed. Pathologically, the degree of tumour cell and fibrosis distribution in the lesion was semi-quantitatively evaluated.
Results: 4 enhancement patterns were observed in the arterial phase for 32 mass-forming ICCs: peripheral rim-like hyperenhancement (n=19); heterogeneous hyperenhancement (n=6); homogeneous hyperenhancement (n=3); and heterogeneous hypo-enhancement (n=4). Among the four enhancement patterns, the differences in tumour cell distribution were statistically significant (p<0.05). The hyperenhancing area on CEUS corresponded to more tumour cells for mass-forming ICCs. Heterogeneous hyperenhancement (n=2) and heterogeneous hypo-enhancement (n=2) were observed in the arterial phase for four periductal infiltrating ICCs. In this subtype, fibrosis was more commonly found in the lesions. Heterogeneous hyperenhancement (n=1) and homogeneous hyperenhancement (n=3) were observed in the arterial phase for four intraductal growing ICCs. This subtype tended to have abundant tumour cells.
Conclusion: The CEUS findings of ICC relate to the degree of carcinoma cell proliferation at pathological examination. Hyperenhancing areas in the tumour always indicated increased density of cancer cells.