Fibronodular hepatocellular carcinoma - a new variant of liver cancer: clinical, pathological, and radiological correlation

Purpose: We aimed to confirm a novel subtype of HCC and evaluate the histologic, clinical, and radiologic differences compared to the conventional and scirrhous vari-ants of HCC. Materials and Methods: 24 scirrhous (SC-HCC) and 29 fibronodular (FN-HCC) lesions were classified by a board-certified pathologist. randomly selected. 30 conventional (CV-HCC) lesions were subsequently chosen from a total of 290 cases. Primary clini-cal information at diagnosis was systematically gathered at baseline. Time to progres-sion and overall survival were analyzed by means of a Kaplan-Meier curve. The imag-ing features of scirrhous and fibronodular variants were analyzed on contrast-enhanced MRI based on the major and ancillary criteria of the Liver Imaging Reporting and Data System (LI-RADS), a board-certified radiologist. Feature differences were further examined with Fisher’s exact test. A correlation of features on imaging and his-tology was conducted. Results: Overall survival rates were similar among all groups (p=0.956). However, time to progression varied significantly between fibronodular HCC and conventional HCC (p=0.003). Even though FN-HCC and SC-HCC share remarkably similar histological features, SC-HCC seemed to have increased rates of washout (p=0.0001) and an ap-pearance on delayed imaging as multiple hypointense nodules embedded into en-hancing septations (p