Imaging features of combined hepatocellular-cholangiocarcinoma on contrast-enhanced ultrasound: correlation with clinicopathological findings

Aim To evaluate the relationship between the imaging features of combined hepatocellular–cholangiocarcinoma (CHC) on contrast-enhanced ultrasound (CEUS) and clinicopathological findings. Materials and methods From August 2004 to August 2016, 40 patients (29 males, 11 females; mean age 52.8±11.2 years) with histopathologically proven CHC were investigated. The CEUS imaging features and clinicopathological findings of CHC were analysed and compared retrospectively. Results On CEUS, peripheral irregular rim-like enhancement, diffuse heterogeneous enhancement, and diffuse homogeneous enhancement was illustrated in 13 (32.5%), 21 (52.5%), and six (15%) lesions, respectively. Histopathological findings showed hepatocellular carcinoma (HCC) predominance and cholangiocarcinoma (CC) predominance throughout the tumour were illustrated in 21 (52.5%) and 19 (47.5%) cases, respectively. HCC-predominant CHCs displayed diffuse heterogeneous enhancement more frequently than peripheral irregular rim-like enhancement (p=0.005), whereas CC-predominant CHCs displayed peripheral irregular rim-like enhancement more frequently than diffuse heterogeneous enhancement and homogeneous enhancement (p=0.005 and p=0.01, respectively). CHCs >5 cm displayed diffuse heterogeneous enhancement more frequently than diffuse homogeneous enhancement, whereas CHCs ≤5 cm displayed diffuse homogeneous enhancement more frequently than diffuse heterogeneous enhancement (p=0.004). Conclusion The enhancement pattern of CHC on CEUS depended on the relative proportions of the HCC and CC components and showed size-dependent characteristics.