Efficacy of expressions of Arg-1, Hep Par-1, and CK19 in the diagnosis of the primary hepatocellular carcinoma subtypes and exclusion of the metastases.

Abstract

A paraffin-embedded block including 62 cases of primary HCC, and 18 cases diagnosed as metastatic tumors, were subjected for this study using Anti-liver Arginase antibody (ab125134 Cambridge, USA, polyclonal antibody, 3.75 µg/ml), HepPar-1 (polyclonal mouse antibody OCH1E5; 1:600; DAKO, CA, USA), and CK 19 Anti-Cytokeratin 19 antibody (ab15463, rabbit polyclonal antibody; 1:100; Cambridge, USA). The intensity of immunostaining was scored (0 to 3+). Nuclear and cytoplasmic staining with Arg-1 and cytoplasmic for both HepPar-1 and CK 19 are reported. The histopathological patterns were mainly trabecular no= (24, 38.7%), and pseudoglandular (no=14, 22.5%), mixed hepatocellular cholangiocarcinoma was observed in one case (1.6%). Arginase-1 positivity was in 55 cases (88.7%) opposite to 46 (74.19%) and 8 (12.9%) for HepPAr.1% -1 and CK 19, respectively. The intensity of expression was marked in well and moderate differentiation for Arg-1 and HepPar-1and in poorly differentiated for CK 19. Metastatic carcinoma cases revealed two cases positive for Arg-1 (11.1%), 4 cases (22.2%) positive for HepPar-1, and 13 cases (72.2%) positive for CK 19. Arg-1 and HepPar-1 are confirmative in the diagnosis of primary HCC in most cases, either separately or collectively but the priority of selection leans more towards Arg-1. Arg-1 and HepPar-1 positive with negative CK 19 expressions give more support to diagnosis of primary HCC while the reverse will support the diagnosis of tumour of biliary origin or liver metastasis.