Small hepatocellular carcinoma: ultrasonographic findings and histopathologic correlation.

It is known that small hepatocellular carcinoma (HCCs) were usually hypoechoic at ultrasonography (US). In this study, we analyzed US findings of 42 small HCCs less than 2 cm in diameter and correlated them with histopathologic findings. US parameters were tumor size, tumor echogenecity, and morphologic features (peripheral halo, lateral shadow, posterior enhancement, and mosaic pattern), while histopathologic parameters were Edmonson grade and microscopic features (coagulation necrosis, interstitial fibrosis, fatty metamorphosis, sinusoidal dilatation, hemorrhage, encapsulation, and internal septation). One-third of HCCs was not hypoechoic. Tumor echogenecity and morphologic features were variable, regardless of tumor differentiation and microscopic features. In our study, it seemed that US detected histopathologic changes in small HCCs more frequently than previously known, but none of these US findings could suggest a specific histopathologic finding in small HCCs less than 2 cm in diameter.