CLINICAL-FEATURES OF SMALL HEPATOCELLULAR CARCINOMAS AS ASSESSED BY HISTOLOGIC GRADES

Background. Ninety-seven patients with small hepatocellular carcinomas (HCCs) measuring 3 cm or less in size and three patients with adenoma tous hyperplasia who underwent radical hepatic resection were examined in this study. Methods. The lesions were classified into four groups according to the following histologic grading criteria: group A, adeno matous hyperplasia (n = 3); group B, early HCC (n = 6); group C, well- differentiated HCC (wHCC) (n = 32); and group D, moderately or poorly differentiated HCC (n = 59). The involvement factors that seemed to be important or to characterize the progression of HCC and the survival rates were compared among the four histologic groups. Results. The fre quency of patients with tumors larger than 2.0 cm in size and that of patients with 200 or more ng/ml serum alpha-fetoprotein increased with the progression of histologic malignancy. Tumor staining on the angio gram, capsular formation, and extranodular invasion were never seen in groups A and B, but they began to appear in group C and increased rem arkably in group D. The 5-year survival rates of the patients in group B, C, and D were 100%, 60%, and 27%, respectively, and statistically significant differences were seen among them. In comparative evaluatio n of the group C patients the lesions that showed no tumor staining ha d no capsule, and those that had no capsule had no extranodular invasi on. The 5-year survival rate of patients with wHCC without extranodula r invasion (81%) was significantly higher than that of patients with e xtranodular invasion (35%) (p < 0.05). Conclusions. It may be recommen ded to provide the category of wHCC without extranodular invasion of p athologic classification of clinically early HCC (i.e., HCC of high cu rability).