Ectopic liver and hepatocarcinogenesis.

Hepatocellular carcinomata are relatively rare in the western hemisphere, but they are much more common in South-East Asia and sub-Saharan Africa due to high endogenous levels of hepatitis B and C. Ectopic liver tissue usually is found incidentally (frequently at cholecystectomy), but it may also be found due to neoplastic changes or compressive effects. Ectopic liver tissue has an increased neoplastic potential over orthotopic liver, which we postulate is due to compromised vascular supply and biliary drainage. These lesions may be susceptible to surgical resection, although long-term follow-up data are poor. Ectopic or accessory liver tissue is a rare condition. Most commonly, it is found incidentally, but it may also be found as a result of neoplasia or compressive effects. These lesions appear to have an increased potential for the development of hepatocellular carcinoma in the absence of malignancy in the mother liver. Due to their anatomical features, these carcinomata appear to be susceptible to curative resection, although long-term follow-up data are poor. These carcinomata have been reported more frequently from South-East Asia than from Western countries; however, the common risk factors for hepatocellular carcinoma, such as infection with hepatitis B or C and cirrhosis, appear to be less implicated than in carcinomata of the orthotopic liver. In ectopic or accessory liver tissue, development of hepatocellular carcinoma may be the result of compromised vascular supply or biliary drainage.