Well-differentiated hepatocellular carcinoma smaller than 15 mm in diameter totally eradicated with percutaneous ethanol injection instead of radiofrequency ablation

We describe three cases of well-differentiated hepatocellular carcinoma (HCC) smaller than 15 mm in diameter completely eradicated with percutaneous ethanol injection (PEI) instead of using radiofrequency ablation (RFA). Ultrasound (US) examination revealed one nodule each in segment 2 (hypoechoic, near bile ducts, 10 mm), in segment 5 (hyperechoic, near the gall bladder, 15 mm), and in segment 7 (hypoechoic, near the diaphragm, 15 mm). Although imaging studies revealed isovascular (case 1) and hypervascular (cases 2 and 3) nodules, histological analysis of US-guided biopsy tissue revealed well-differentiated HCC. In consideration of the location of the nodules, PEI, instead of RFA, was administered and the nodules were rendered necrotic. Although RFA is superior to PEI in the treatment of small HCCs from the viewpoint of treatment response and long survival, PEI is strongly recommended for HCCs located near bile ducts, the gall bladder, and the diaphragm, especially when the nodules are smaller than 15 mm in diameter.