Immunohistological patterns of immunoglobulins in dysplasias, benign neoplasms and carcinomas of the breast.

IgA, IgG, IgM and IgE were studied in 61 carcinomas, 24 tissues peripheral to carcinomas, 16 benign neoplasms and 15 dysplasias of the breast. Mono- and double-layer direct immunofluorescence procedures applying FITC- and TRITC-conjugated antisera were used on cryostat and paraffin sections for evaluation of immunoglobulins in plasma cells, cancer cells and ductal epithelium. Plasma cells of all Ig classes were more frequent in carcinomas, especially of medullary and poorly differentiated ductal types, than in benign lesions. In all groups of benign lesions and in carcinomas with scanty lymphocytes and plasma cells there was a predominance of IgA-synthesizing plasma cells. Carcinomas with marked local response had an increased proportion of IgG cells. IgE plasma cells were rare. IgA and IgM were more frequent in ductal epithelium than in cancer cells, especially of poorly differentiated tumors. No appreciable IgG was observed in ductal or cancer cells. Our results indicate a correlation between immunohistologic patterns of immunoglobulins and histologic characteristics of carcinomas.