RESUMEN
<p><b>OBJECTIVE</b>To investigate the relationship between Transitional CK19 positive cells and hepatic precancerous lesion in chronic hepatitis B patients.</p><p><b>METHODS</b>We observed the expression of CK19 in liver tissue of chronic hepatitis B patients by LSAB immunohistochemical staining, and examined serum AFP and ultrasonography one time per 3 months for one year.</p><p><b>RESULTS</b>We observed a population of CK19 positive cells-with size and structure between those of human oval cells and mature hepatocytes-that usually occurred along with oval-cell proliferation. It was suggested that these transitional cells may partly account for the elevation of serum AFP. One patient occurred hepatic carcinoma, another patient had low-echogenic nodules in liver parenchyma within the 1 year follow-up period.</p><p><b>CONCLUSION</b>Transitional CK19 positive cells could be regarded as a new possible pathological marker of hepatic precancerous lesion.</p>