Occult viral hepatitis and noncirrhotic hepatocellular carcinoma.

The achievement of a sustained virologic response to hepatitis C antiviral therapy represents a milestone occurrence that many tout as a cure. Recent studies, however, have found trace HCV viral material both among sustained responders and in patients with chronic liver disease who are HCV RNA negative, suggesting the entity of occult hepatitis C. As a body of literature emerges on the pathogenic role of occult hepatitis B, little is known of the potential importance of occult type C hepatitis. Specifically, occult hepatitis B has been strongly implicated as a culprit that facilitates the development of hepatocellular carcinoma, typically in the background of cirrhosis. Those cancers that develop in noncirrhotic livers, an especially rare entity in the West, usually occur in the setting of smoldering liver injury, often with some degree of fibrosis. The role of multiple hepatotoxins acting in concert to potentiate hepatic carcinogenicity has become increasingly recognized, including viral coinfection. The finding of occult hepatitis B in noncirrhotic hepatocellular carcinomas among patients with hepatitis C who achieved antiviral sustained virologic response raises provocative theories regarding the natural history of both of these viral hepatitis agents.