Immunoreactivity to monoclonal antibody, Hep Par 1, in human hepatocellular carcinomas according to histopathological grade and histological pattern
Introduction
In 1993, Wennerberg et al. [1] prepared a new monoclonal antibody, hepatocyte paraffin 1 (Hep Par 1), which reacted with both normal and neoplastic hepatocytes in formalin-fixed, paraffin-embedded tissue sections. The use of this antibody resulted in a distinct, granular cytoplasmic staining of hepatocytes but did not stain bile ducts or non-parenchymal liver cells. Since then, the antibody has been used to differentiate primary liver tumors from metastatic liver tumors, as well as hepatocellular carcinoma (HCC) from cholangiocarcinoma or combined tumors [2], [3]. It has been also used to study liver development [4] and liver regeneration [5]. Therefore, Hep Par 1 is a useful antibody for pathological diagnosis and investigation of liver tumors.
To our knowledge, all studies that have so far used Hep Par 1 for HCCs reported that the antibody reacts with almost all HCCs, irrespective of the degree of differentiation [3], [6]. Detailed analysis of the staining pattern of HCC based on histopathological grade has not yet been reported. In the present study, we analyzed Hep Par 1 immunoreactivity in HCCs based on histopathological grade and histological pattern.
Section snippets
Materials and methods
Liver tissues were obtained from 12 autopsy cases of primary HCC. The patients’ age at death ranged from 48 to 82 years (average, 63.8 years), and male:female ratio of 11:1. In 11 cases, HCC was associated with liver cirrhosis. A total of 61 tissue blocks were obtained from HCC areas in these cases. The liver specimens were fixed in 10% neutral buffered formalin solution and embedded in paraffin. They were then cut into 4-μm-thick sections and mounted on 3-aminopropyltriethoxysilane coated
Histological grade and pattern
Using the histopathological grade and histological pattern defined above, we classified H–E/Gomori stained sections of HCC into six different categories, (1) well-differentiated HCC of trabecular type (W and T); (2) well-differentiated, pseudoglandular type (W and P); (3) moderately, trabecular type (M and T); (4) moderately, pseudoglandular type (M and P); (5) poorly, compact or trabecular type (P and C); and (6) undifferentiated carcinoma type (U). The number of areas in each category is
Discussion
Wennerberg et al. [1] reported that Hep Par 1 reacted with almost all HCCs with the exception of one case of sclerosing HCC. However, they did not describe the reactivity based on histopathological grade or structural pattern. In the present study, we found that (1) well-differentiated, trabecular type HCCs were always strongly positive for Hep Par 1 and showed a similar reactivity to non-tumorous trabecular hepatic cord; (2) immunoreactivity to Hep Par 1 in HCC diminished with decreased
References (10)
- et al.
Identification of bipotential progenitor cells in human liver development
Hepatology
(1996) - et al.
Hepatocyte Paraffin 1: A monoclonal antibody that reacts with hepatocytes and can be used for differential diagnosis of hepatic tumors
Am. J. Pathol.
(1993) - et al.
Utilization of hepatocyte-specific antibody in the immunocytochemical evaluation of liver tumors
Mod. Pathol.
(1997) - et al.
Hep Par 1 and selected antibodies in the immunohistological distinction of hepatocellular carcinoma from cholangiocarcinoma, combined tumours and metastatic carcinoma
Histopathology
(1998) - et al.
Identification of bipotential progenitor cells in human liver regeneration
Lab. Invest.
(1996)