IMMUNOHISTOCHEMICAL STAINING OF HEPATOCELLULAR-CARCINOMA WITH MONOCLONAL-ANTIBODY AGAINST INHIBIN

Inhibin is a peptide hormone produced by ovarian granulosa cells. Duri ng a recent study investigating the immunohistochemical staining of ov arian granulosa cell tumours and other neoplasms with an anti-inhibin monoclonal antibody, we identified strong cytoplasmic staining of hepa tocytes. In the present study we investigated the immunostaining of he patocellular carcinoma and other neoplasms involving the liver with an ti-inhibin to determine whether the antibody may be of value in the di fferential diagnosis of hepatic neoplasms, Immunostaining for alpha-fe toprotein was also performed, With anti-inhibin there was positive, ge nerally strong, cytoplasmic staining of 17 of 19 cases of hepatocellul ar carcinoma, including the pleomorphic and glandular variants, There was positive staining of six of 20 cases of adenocarcinoma, In these, positive staining was generally focal, of weal; intensity and involved the luminal surface of neoplastic glands, There was no staining of fi ve cases of neuroendocrine tumour, There was positive staining for alp ha-fetoprotein in 13 of 19 cases of hepatocellular carcinoma and in tw o of 20 cases of adenocarcinoma but no staining of neuroendocrine tumo urs, Immunostaining with anti-inhibin antibody may be of value in the differentiation of hepatocellular carcinoma from other neoplasms invol ving the liver, The antibody is a more sensitive, but less specific, i mmunohistochemical marker for hepatocellular carcinoma than is alpha-f etoprotein.