Hepatocellular carcinoma: reduced frequency of typical findings with dynamic contrast-enhanced CT in a non-Asian population.

Four computed tomographic (CT) findings have been described as typical or diagnostic of hepatocellular carcinoma: Primary morphologic findings include tumor encapsulation and fatty metamorphosis and secondary findings include venous invasion and arterioportal shunting. However, virtually all of the articles reporting these findings with significant frequency have been from Japan and thus represent an almost purely Asian population. The authors analyzed a series of 93 patients with hepatocellular carcinoma, only eight of whom were Asian. With the exception of venous invasion (48%), the analysis showed that while the four CT features may be typical of hepatocellular carcinoma, three features occurred with low frequency in a non-Asian population: tumor encapsulation, 12%; fatty metamorphosis, 0%; and arterioportal shunting, 4%. In addition, a review of the literature showed that all of the findings have occurred in other hepatic neoplasms, including benign and metastatic tumors.