Abstract
Purpose: We evaluated the clinicopathological features of hepatocellular carcinoma (HCC) less than or equal to 2cm in diameter, and clarified which tumors should be resected anatomically to improve prognosis. Patients and methods: Of 508 HCC cases under going hepatectomy from 1990 to 2003, 63 less than or equal to 2 cm in maximum diameter were studied. We evaluated clinicopathological features, the effectiveness of anatomical resection, and recurrence-free survival, classified by gross appearance or tumor size. We also evaluated univariate and multivariate analysis of recurrence. Results: Small nodular type with indistinct margins (Type 0) accounted for 11. 1%, simple nodular type (Type 1) for 63. 5%, simple nodular type with extranodular growth (Type 2) for 19. 0%, and confluent multinodular type (Type 3) for 6. 3%. In cases of Type 2+3 or more than 1. 5cm, the number of portal vein invasions and intrahepatic metastasis increased, while the proportion of well-differentiated HCC in these cases decreased. Disease-free survival was significantly better in anatomical resection (n=24) than in nonanatomical resection (n=39). In cases of Type 2+3 or more than 1. 5cm, disease-free survival was also significantly better in anatomical resection. Anatomical resection, preoperative platelet counts of >120, 000/mm3, and nonportal vein invasion were significantly better prognostic factors in recurrence-free survival according to univariate analysis, and anatomical resection and nonportal vein invasion were also significant according to multivariate analysis. Conclusion Clinicopatholigic variation was wide even in HCC under 2cm. Biological malignant potential increased in cases of Type 2+3 or more than 1. 5cm, in which case anatomical resection is effective.
