Prognostic histologic features of resected small hepatocellular carcinoma (HCC) in Taiwan. A comparison with resected large HCC.

The morphologic features and their prognostic significance were analyzed in 83 surgically resected hepatocellular carcinomas (HCC): 44 of them were of less than or equal to 5 cm in diameter and 39 were larger. This study demonstrated a high prevalence of tumor capsule in both small and large HCCs, 86.4% and 84.6%, respectively. In small HCC, the capsule formation was significantly higher in the liver with cirrhosis (96.9%, or 31/32) than without (58.3%, or 7/12) (P less than 0.003). In both small and large HCCs, the most important histologic parameter influencing the tumor recurrence was the liver invasion. In the small but not in the large HCC, the invasion through the capsule also correlated well with recurrence (P less than 0.05). None of the 19 patients whose HCC were confined by a tumor capsule and did not invade the liver, had a recurrence during the 10 months or longer follow-up period. The significantly more favorable outcome of smaller HCC was related to the lower frequencies of liver invasion (P less than 0.001), portal vein involvement (P less than 0.01), and satellite formation (P less than 0.01). Tumor recurrence did not correlate with the tumor grading, presence of clear cells, liver cell dysplasia, or host inflammatory response. The HBsAg positivity in tumor cells was significantly higher in small (40.9%, or 18/44) than in large HCC (10.3%, or 4/39), suggestive of a gradual loss of the cytoplasmic expression of HBsAg in the tumor cells during the growth of HCC.