Normal serum proteins in female breast carcinomas and fibroadenomas. An immunohistochemical study.

Several serum proteins were immunohistochemically studied in benign and malignant breast lesions in 13 patients. The majority of infiltrating duct and lobular carcinomas showed albumin and IgG abundant immune reactive cells. Fewer cells contained immune reactive alpha-1-antitrypsin and transferrin. Staining was diffuse and limited to the cell cytoplasm. Immune reactive cells alternated with non reactive ones in a characteristic heterogeneous pattern. The parenchymal cells in carcinomas were non reactive to ceruloplasmin, fibrinogen and alphafetoprotein. Myoepithelial and epithelial cells in fibroadenomas were also positive for albumin and IgG, but less frequently for alpha-1-antitrypsin and transferrin. Normal breast tissue surrounding fibroadenomas as well as a lactational adenoma showed no immune reactive cells. Mechanisms that may be involved with the presence of plasma proteins in the cytoplasm of parenchymal cells in breast lesions are discussed.