Diffuse intrahepatic recurrence after percutaneous radiofrequency ablation for solitary and small hepatocellular carcinoma

Two patients developed segmental, diffuse intrahepatic recurrence after percutaneous radiofrequency ablation (RFA) to treat a primary, solitary, and small (2.5 cm) hepatocellular carcinoma (HCC). Despite the size of the HCC, levels of the tumor markers (α-fetoprotein, α-fetoprotein-L3%, and des-γ-carboxyprothrombin) were all elevated before RFA, and tumors in both patients were contiguous with a major branch of the portal vein. Tumor biopsies of both patients revealed moderately differentiated HCC but diagnostic imaging showed an area of reduced tumor blood flow, suggesting a poorly differentiated component. Since early detection of post-RFA malignancies by standard ultrasonography and contrast-enhanced computed tomography was difficult, the most sensitive indicator of recurrence in these two patients was the elevated tumor markers. The diffuse intrahepatic recurrence was thought to be caused by increased intratumoral pressure during RFA, resulting in the dissemination of cancer cells through the contiguous portal vein. The clinical course of these tumors indicate that the choice of RFA should be carefully considered when treating specific subtype of HCC that is adjacent to main portal vein branch and involves a possible poorly differentiated component and that surgical resection or combinations of RFA with other treatment modalities such as transcatheter arterial chemoembolization should be considered as alternative treatment strategies.