Cellular composition of the nipple aspirate specimen of breast fluid. I. The benign cells.

A nipple aspirator device was used to obtain breast secretions for cytologic examination, as well as for viral and biochemical analysis. Examination of the first 1,456 specimens from 796 women revealed ductal epithelium in 54%. Ductal epithelial cells were often absent in specimens from normal women; however, 78.5% of women with benign breast disease on tissue biopsy had specimens containing ductal epithelium. Apocrine metaplastic cells were a further indication of the presence of breast disease, and were rarely found in specimens from asymptomatic women. Foam cells were often abundant in specimens from normal breasts, but were found in decreased numbers in specimens from women benign breast disease. Differences in the occurrence of ductal epithelial cells, apocrine metaplastic cells, and foam cells suggest an alteration in the rate of maturation of ductal epithelium in women with both benign and malignant breast disease. The finding of a relative abundance of cells in nipple aspirate specimens from women with breast disease and few or no cells in specimens from women with normal breasts is believed to be of great importance in the cytologic evaluation of nipple aspirate specimens.