The paper presents approaches the topic of hepatocellular carcinoma (HCC) differential diagnosis with various other malignant tumors, as such differentiation can be in many cases performed only based on a thorough immunohistochemical marker designed for hepatocellular differentiation. Hepatocyte paraffin-1(Hep Par-1), is a specific antibody for hepatocellular tissue that is represented within both healthy and malignant hepatic cells. The paper evaluated the expression of Hep Par-1 on paraffin tissue acquisitions of selected cases of resecable hepatocellular carcinoma referred for curative surgery (20 cases). For the experimental part, mouse anti-human hepatocyte monoclonal antibodies, Hepatocyte Ab1,and diluted clones of OCH1E5 with the EnVision technique have been used. The results were suggestive for positive expression of Hep Par-1 in 15 of the 20 cases of HCC (75%), with various degrees secondary to the differentiation degree (which was positive in all 15 G1-G2 HCCs and negative in 5 G3-G4 HCCs); on the other hand, the study showed a non-homogenous and focal Hep Par-1 distribution malignant tissue engaging a uniform staining of the non-tumorous liver tissue surrounding the lesion. The study did not show Hep Par-1 immunostaining in non-hepatocytic tumors, excepting some focal expression on a gastric adenocarcinoma with clear patchy expression. Our research confirms that Hep Par-1 can be considered a valuable marker in the diagnosis of HCC, although not totally specific; thus, it should be used in a conjugated manner with various other markers useful in hepatocellular differentiation.
Keywords: hepatocellular carcinoma, metastatic carcinoma, Hep Par-1, differential diagnosis of HCC