Intrahepatic dissemination of hepatocellular carcinoma after local ablation therapy

We aimed to clarify the histological features of and risk factors for intrahepatic dissemination after local ablation therapy (LAT) for hepatocellular carcinoma (HCC). Between April 1992 and December 2005, 192 HCC patients underwent hepatic resection at our department, among whom were 17 patients who had local recurrences after LAT. Eight of these 17 patients had intrahepatic dissemination. The clinical and histological characteristics of these 8 surgically treated patients with intrahepatic dissemination were investigated. Histologically, numerous intrahepatic metastases were observed, mainly in the same section as the treated tumor, together with main or sectional portal vein tumor thrombi. Before the ablation therapy, the average tumor diameter was 2.1 cm, and 62.5% of the tumors were adjacent to the main or sectional portal vein. In terms of therapeutic factors, 25% of the patients had a prior needle biopsy and 62.5% had insufficient safety margins. LAT for HCCs (even those less than 3 cm in diameter) adjacent less than 5 mm to the main or sectional portal vein possibly promotes intrahepatic dissemination.