MR Features Based on LI-RADS Ver. 2018 Correlated with Cytokeratin 19 Expression in Combined Hepatocellular Carcinoma-Cholangiocarcinoma

PURPOSE: To investigate the significance of MR features based on the Liver Imaging Reporting and Data System (LI-RADS ver. 2018) for identifying the expression of cytokeratin 19 (CK-19) in patients with combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) before surgery. PATIENTS AND METHODS: The study enrolled 174 patients pathologically confirmed to have cHCC-CCA according to the 2019 WHO classification. The preoperative MR imaging features and clinicopathological findings were retrospectively evaluated and compared between the CK-19-positive and CK-19-negative cHCC-CCA groups. RESULTS: One hundred seventy-four patients (mean age, males vs females: 56.6 ± 10.0 years vs 54.7 ± 14.2 years) were evaluated. The presence of mosaic architecture, targetoid appearance, cholangiectasis, hepatic capsule retraction, and corona enhancement was significantly higher in the CK-19-positive group (all p < 0.05), while nonrim arterial phase hyperenhancement (APHE) was more common in the CK-19-negative group (p = 0.04). The univariate analysis showed that hepatitis B virus infection, CEA > 5 ng/mL, tumor size, nonrim APHE, mosaic architecture, targetoid appearance, cholangiectasis, hepatic capsule retraction, and corona enhancement were significant risk factors for CK-19-positive cHCC-CCA (all p < 0.05). Unfortunately, the multivariate analysis revealed that only corona enhancement (OR = 2.359, p = 0.03) was an independent risk factor associated with CK-19-positive cHCC-CCA. CONCLUSION: Corona enhancement is significantly correlated with CK-19 positivity in patients with cHCC-CCA.