Immunoperoxidase detection of carcinoembryonic antigen in fine needle aspirates of breast carcinoma. Correlation with studies in tissue sections.

The peroxidase-antiperoxidase technique was used to demonstrate the presence of carcinoembryonic antigen (CEA) in fine needle aspirates and the corresponding tissue sections in 50 cases of carcinoma of the breast. The incidence of CEA positivity in the aspiration smears was 76%. A good correlation was observed between the results in the aspiration smears and in the tissue sections: 82% in the initial correlation and 90% when additional tissue sections from four of nine discordant cases proved to be positive for CEA. Five cases remained positive for CEA in the aspiration smears and negative for CEA in the tissue sections. This preliminary data indicates that aspiration smears can be used to demonstrate the CEA status in mammary carcinomas.