A histopathologic study of early hepatocellular carcinoma.

In a series of 94 autopsy cases of hepatocellular carcinoma (HCC), 8 cases of minute HCC (less than 3.5 cm in diameter) were included. These cases had some additional nodular foci that revealed a possible histogenesis of HCC. The lesion was first noted as a group of basophilic liver cell cords in a limited area of a hyperplastic nodule. The cords showed acinar formation, bile congestion, and increase of stromal fibers with disappearance of sinusoids. When certain numbers of lobules were occupied by the basophilic liver cells, a dysplastic nodule was produced wherein the portal triads tended to disappear. Despite marked necrotic tendency, the liver cells proliferated actively and replaced the adjacent cirrhotic lobules. The process might be induced and enhanced by repeated episodes of necrosis and regeneration occurring in cirrhotic livers. Some minute HCC nodules had common features with those seen in the dysplastic nodule. Histologic findings of minute HCC nodules were also described and discussed in terms of their growth pattern.