Screening and diagnosis of hepatocellular carcinoma.

Early diagnosis of hepatocellular carcinoma (HCC) is feasible because HCC develops in the background of well-known, readily identifiable and potentially avoidable environmental risk factors. According to the American Association for the Study of the Liver Diseases and the European Association for the Study of the Liver, patients with cirrhosis and carriers of chronic viral hepatitis are the target of surveillance to be investigated with abdominal ultrasounds (US) every 6 or 12 months. The diagnostic confirmation of a > or =2 cm nodule in patients with cirrhosis detected during surveillance is possible with any imaging technique among second-generation contrast US, contrast computed tomography and gadolinium-contrast magnetic resonance imaging. HCC shows an early hyperenhanced arterial vascularization, followed by enhanced hypoattenuation (wash-out) in the late phase of imaging. In patients with a < or =2 cm nodule, two imaging techniques are required for the final diagnosis, which, however, have a relatively low diagnostic sensitivity (33%). Nodules with negative imaging findings need to be investigated further with an echo-guided liver biopsy or enhanced follow-up with imaging (every 3 months) to reach a final diagnosis. The cost-effectiveness ratio of surveillance depends on multiple factors, like HCC incidence, the cost and accuracy of diagnostic tests and the costs and outcome of the therapeutic interventions.