Aspiration of the breast and nipple discharge cytology.

Between 1 January 1974 and 30 June 1984, 1,003 specimens obtained from the breast were submitted for cytologic evaluation to the Department of Pathology at the Waterbury Hospital Health Center. Eighty-eight per cent were obtained by fine needle aspiration of a palpable mass; the remainder were smears of nipple discharges. Precytologic and postcytologic clinical data were available for 80 per cent of the specimens. In the fine needle aspiration group, there were 219 instances of proved carcinomas; 79 per cent of these had either positive or suspicious cytologic findings. Seventy-five per cent of the patients with positive cytologic results underwent mastectomy without prior histologic confirmation of the needle aspiration and all were confirmed as malignant growths. There were 41 false-negative aspirates which were reviewed in detail. The cytologic slides of 24 of the 41 false-negative aspirates were available for re-evaluation by a second, independent cytopathologist. Only one was thought to have been misread initially; the remainder appeared to have been falsely negative for technical reasons related to aspiration or fixation technique or tumor size less than 1 centimeter. There was one false-positive finding in a patient who was found to have fat necrosis at biopsy. Results of nipple discharge cytology were less accurate. Positive or suspicious cytology was found in only five of 11 proved instances of carcinomas. There was one false-positive and five false-negative results in this group. We conclude that needle aspiration of palpable masses of the breast is an accurate, cost effective procedure which is readily adaptable to a community hospital, provided that a pathologist with an interest in cytology is available.