Multistep human hepatocarcinogenesis: correlation of imaging with pathology.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. The majority of HCCs develop in cirrhotic livers, and the early detection and characterization of this entity is very important. Pathologically, human HCC develops in a multistep fashion in the following sequence: from low-grade dysplastic nodule (LGDN), to high-grade dysplastic nodule (HGDN), early HCC, well-differentiated HCC, nodule-in-nodule HCC, and, finally, to moderately differentiated HCC. Differentiation between early HCC and DN is the most important issue in the clinical setting. CT during hepatic angiography (CTHA) and CT during arterial portography (CTAP) are the most sensitive tools in the differentiation of premalignant/borderline lesions (LGDN and HGDN) and early HCC. Recent progress in imaging modality, especially Sonazoidenhanced US and Gd-EOB-DTPA MRI, is starting to play a very important role in the imaging of multistep hepatocarcinogenesis, resulting in changing the therapeutic strategy of these nodular lesions associated with liver cirrhosis.