Abstract
Sixteen resected cases of small liver cancer less than 3cm in diameter, detected by imaging diagnosis, were histopathologically studied. 14 out of 16 cases (87.5%) were encapsulated, but they were highly invasive, as was the frequency of capsular invasion 12/14 (85.7%) and of vascular invasion 12/16 (75%), respectively.
The most important factor, which was closely related with the invasiveness, was the histological structure evaluated as growth types.
In "monotonous growth type" which is characterized by its histological homogeneity of atypism, differentiation, or histological types of the tumor tissue, and vascular invasion was significantly rare (p<0.01).
In contrast, "mosaic growth type" which is characterized by varied components with regard to atypism, differentiation, or histological types, was highly invasive.
Serum HBsAg positivity in the small liver cancer cases was 3/16 (18.7%), and the prevalent histological type of HBsAg positive case was macrotrabecular.
In the comparative study of 20 autopsy cases with HBsAg positive liver cancer, there was close association of HBsAg positivity and the macrotrabecular type with a statistical significance (p<0.01), and thus, some similarity in histological findings was found between HBsAg positive small liver cancer and HBsAg positive advanced liver cancer.