Major and ancillary features according to LI-RADS in the assessment of combined hepatocellular cholangiocarcinoma

Abstract

Purpose: Investigate the performance of the LI-RADS v2017 for combined hepatocellular- cholangiocarcinoma (cHCC-CCAs) identifing the features that allow an accurate characterization

Materials and Methods: Sixty-two patients (mean age, 63 years; range, 38–80 years), with pre-surgical biopsy diagnosis of HCC, that underwent hepatic resection, comprised our retrospective study. All patients were subject to Multidetector computed tomography (MDCT), 23 to Magnetic Resonance (MR) study and 9 to contrast enhanced ultrasound (CEUS). The radiologist reported the presence of the HCC by using LIRADS v2018 assessing major and ancillary features.

Results: Final histological diagnosis was HCC for 51 patients and cHCC-CCA for 11 patients. The mean nodule size was 46.0 mm (range 10-190 mm). For cHCC-CCA the mean size was 33.5 mm (range 20-80 mm), for true HCC the mean size was 47.5 mm (range 10-190 mm). According to LIRADS categories: 54 (87.1 %) nodules as defined as LR-5, 1 (1.6%) as LR-3, and 7 (11.3 %) as LR-M. Thirty-nine nodules (63%) showed hyper-enhancement in arterial phase; among them 4 were cHCC-CCA (36.4 % of cHCC-CCA) and 35 (68.6%) true HCC. Forty-three nodules (69.3 %) showed wash-out appearance; 6 cHCC-CCAs (54.5 % of cHCC-CCA) and 37 true HCC (72.5%) had this feature. Only two cHCC-CCA patients (18.2 % of cHCC-CCA) showed capsule appearance. Five cHCC-CCA (71.4 % of cHCC-CCA) showed hyperintensity on T2-W sequences while two (28.6%) showed inhomogeneous signal in T2-W. All cHCC-CCA showed restricted diffusion. Seven cHCC-CCA patients showed a progressive contrast enhancement and satellite nodules.

Conclusion: The presence of satellite nodules, hyperintense signal on T2-W, restricted diffusion, the absence of capsule appearance in nodule that shows peripheral and progressive contrast enhancement are suggestive features of cHCC-CCA.