Imaging of hepatocellular carcinoma: a practical approach.

Imaging of hepatocellular carcinoma (HCC) is complicated because the tumor has a varied radiologic appearance and frequently coexists with cirrhotic regenerative and dysplastic nodules. In cirrhotic patients, any dominant solid nodule that is not clearly a hemangioma should be considered a HCC until proven otherwise, especially if the lesion is hypervascular, of high T2 signal intensity, or demonstrates venous invasion. Biopsy of HCC in cirrhosis is risky and surveillance is often preferable. The doubling time of HCC is 1 to 12 months, and a nodule that is stable over 4 months is very unlikely to be a HCC. However, stable nodules cannot be dismissed, since livers containing dysplastic nodules are at high risk to develop HCC. In noncirrhotic patients, any solid mass that is not clearly a hemangioma or focal nodular hyperplasia is potentially a HCC, and biopsy may be required. Venous invasion by tumor should be distinguished from bland thrombus. Imaging detection of nodal metastases is limited by the frequent finding of benign reactive lymphadenopathy in cirrhosis. Resection is the preferred treatment for HCC, but is contraindicated in the presence of tumors in both lobes, major venous invasion, invasion of adjacent organs other than the gallbladder, tumor rupture, nodal metastases, or distant metastases.