ABSTRACT
Proliferation of a new population of epithelial cells with distinct structure, as well as showing cytokeratin 19 and alpha-fetoprotein expression, was observed in non-neoplastic liver tissues of human hepatocellular carcinoma. Eighteen cases of chronic virus B-hepatitis with hepatomegaly were studied for the presence of oval cells. Oval cells were not observed in 28% [n = 5] of the cases that had only a slightly elevated serum level of alpha-fetoprotein [43.6 +/- 38.2 ng/ml]. Oval cells were detected in 39% [n = 7] of cases showing cirrhosis and a higher serum level of alpha-fetoprotein [221.43 +/- 67.19 ng/ml]. In 33% [n = 6] of cases, oval cells detection was associated with hepatocellular carcinoma and a very high serum level of alpha-fetoprotein [1651 +/- 1106 ng/ml]. So, it is possible that the proliferation of these oval cells may partly account for the elevation of serum levels of alpha-fetoprotein frequently seen in precancerous stages of hepatitis B virus-associated human hepatocellular carcinoma. Also, oval cells may be a useful signal in early detection of malignant transformation in cases of chronic hepatitis B