Sonographic characteristics of small hepatocellular carcinoma.

Fifty-four lesions of small hepatocellular carcinoma under 5 cm in diameter detected by real-time sonography were reviewed to characterize the sonographic feature. Twenty-nine lesions were smaller than 3 cm in diameter and 25 were between 3 and 5 cm in diameter. Sonographic characteristics of hepatocellular carcinoma were peripheral hypoechoic halo (52%), lateral shadow (26%), posterior acoustic enhancement (44%), and mosaic pattern (24%) of the mass. Small tumors less than 3 cm in diameter showed a hypoechoic pattern in half of the cases, whereas most of the tumors between 3 and 5 cm in diameter showed a hyperechoic or mixed pattern. Posterior acoustic enhancement was commonly seen in small tumors less than 3 cm in diameter, while a mosaic pattern was commonly seen in large tumors between 3 and 5 cm in diameter. These results suggest that sonography might be useful for the characterization of small hepatocellular carcinoma.