[Evaluation of aspiration cytology in the diagnosis of mammary tumors].

Aspiration cytology was performed in 1603 patients with breast lesions. Of 298 histologically confirmed malignant tumors, 234 (78.5%) had a concordant cytologic diagnosis. In 75% of 24 patients infiltrating cancer of 1.0 cm or less in greatest dimension, a correct diagnosis was obtained. The ratio of true-positive cases was higher and that of suspicious and false-positive cases lower, in aspiration cytology compared to mammography or echography. Cytologic diagnosis showed 4.7% false-positive results in this series. Atypical cells from intraductal proliferation and low malignant cancer cells were sometimes difficult to distinguish. In patients with such atypical cells, surgical biopsy was required. No difference in the 5-year survival was found between breast cancer patients who had aspiration cytology and their matched controls. Therefore, this method is very safe and is considered to be the most valuable in the correct diagnosis of breast cancer.