Assessment of malignant potential of small hypervascular hepatocellular carcinoma using B-mode ultrasonography.

Aim: Evaluation of malignant potential is important to determine the treatment strategy for small hepatocellular carcinoma (HCC). The aim of the present study was to establish a method of assessing the malignant potential of small hypervascular HCC using B-mode ultrasonography. Methods: One hundred and thirteen arterial hypervascular HCC nodules under 3 cm diagnosed by biopsy or surgical resection (20.5 +/- 6.3 mm) were classified into two groups ultrasonographically: type 1 with (n = 27) and type 2 without (n = 86) a halo. Type 2 was categorized into three subgroups: type 2a, homogenous hyperechoic (n = 9); type 2b, hypoechoic with a smooth margin (n = 35); and type 2c, hypoechoic with an irregular or unclear margin (n = 42). Results: The mean diameter of type 2a nodules was significantly smaller than that of other HCC types (P < 0.05). Overall, moderately differentiated HCC was the predominant histological type, except for type 2a, all of which were well-differentiated HCC. The percentage of poorly differentiated HCC was significantly higher in type 2c nodules (19%) than in other HCC types (P < 0.01). The percentage of Lens culinaris agglutinin-reactive alpha-fetoprotein (AFP-L3) positivity was significantly higher in type 2c nodules (55%) than in other HCC types (P < 0.01). Classification on B-mode ultrasonography was correlated with the histological differentiation and serum level, an indicator of a poor prognosis. Conclusion: The malignant potential of type 2a is the lowest and that of type 2c is the highest, both histologically and serologically. Assessment of the malignant potential of small, hypervascular HCC is possible by B-mode ultrasonography.