Abstract

A panel of seven monoclonal antiepithelial antibodies of different specificities, including anticytokeratin, human milk fat globule membrane, C, and carcinoembryonic antigen (CEA) were used with the alkaline phosphatase-antialkaline phosphatase (APAAP) immunostaining technique to determine their value in the differentiation between benign and malignant mesothelial cells and lung carcinoma in histological preparations. The anticytokeratin antibody reacted strongly with all cases of reactive mesothelium, mesothelioma, and lung carcinoma. Antibodies to human milk fat globule membrane and the Ca antigen stained mesothelioma and carcinoma and 43% of cases of reactive mesothelium. Staining for carcinoembryonic antigen was not detected in reactive mesothelium or mesothelioma, but was present in most of the lung carcinomas. CEA seemed to be the single most useful marker in distinguishing carcinoma from mesothelioma in that a positive reaction for CEA would indicate carcinoma rather than mesothelioma.