IMMUNOHISTOCHEMICAL DISTINCTION OF HUMAN CARCINOMAS BY CYTOKERATIN TYPING WITH MONOCLONAL-ANTIBODIES

Abstract

Carcinomas of different origin have been tested in immunofluorescence microscopy with the monoclonal murine antibodies CK1-CK4, which recognize a single cytokeratin polypeptide (human cytokeratin No. 18) present in simple but not in stratified squamous epithelia, and with the monoclonal antibody KG8.13 and guinea pig kerA antibodies, both of which recognize a variety of cytokeratins common to almost all epithelia cell types. Tumors derived from simple epithelia, including adenocarcinomas and some other tumors such as ductal breast carcinomas, were strongly stained by all 3 antibodies, as was a transitional carcinoma of the bladder. Basal cell epithelioma, cloacogenic carcinoma and squamous cell carcinoma of skin, tongue and esophagus appeared negative with CK1-CK4 but positive with the other 2 antibodies. Other squamous cell carcinomas derived from epiglottis and cervix uteri showed a mixture of positive and negative cells when tested with CK1-CK4, although all tumor cells were positive when tested with KG8.13 and with kerA. Use of an appropriate collection of cytokeratin antibodies with different specificities allows tumors of epithelial origin to be distinguished from other tumor types and allows a further subdivision of carcinomas in relation to their histologic origin.