Rate of local tumor progression following radiofrequency ablation of pathologically early hepatocellular carcinoma

Figure 3 A 74-year-old man with an early hepatocellular carcinoma lesion (maximum diameter, 20 mm) in segment III of the liver. A: Pretreatment contrast-enhanced magnetic resonance imaging (MRI) with Gd-EOB-DTPA obtained during the arterial phase shows the tumor (arrowheads), with the tumor appearing as a partially hyper-intense area; B: Conventional ultrasonography (US) shows the tumor as an almost hyper-echoic and a partially hypo-echoic lesion (arrowheads); C: Contrast-enhanced US image obtained during the arterial phase (left side) shows the enhancement of almost the entire tumor (arrowheads). The contrast-enhanced US image obtained during the post-vascular phase (right) shows a partially hypo-echoic lesion (arrowheads); D: Contrast-enhanced US obtained during the arterial phase 1 d after radiofrequency ablation (RFA) shows the ablated lesion as an avascular area, and the dotted-line circle shows the site of the tumor (left side). A contrast-enhanced MRI image with Gd-EOB-DTPA obtained during the hepatobiliary phase before RFA is shown as a reference (right side). The ablative margin was evaluated as less than 5 mm because the portal vein was near (arrows); E: Victoria blue staining, showing elastic fibers surrounding the portal tract in blue, reveals stromal (portal tract) invasion compatible with a diagnosis of early hepatocellular carcinoma (arrowheads); F: Post-treatment contrast-enhanced MRI with Gd-EOB-DTPA shows local tumor progression at 636 d after ablation. The arrows indicate the ablative zone, and the arrowheads indicate the recurrence of the tumor, which appeared as a hyper-intense area during the arterial-phase. HCC: Hepatocellular carcinoma.