Positive predictive value of fine needle aspiration cytology of breast lesions.

The predictive value of fine needle aspiration (FNA) was assessed in 1,181 consecutive cases of breast lesions in which cytologic abnormalities were reported. The positive predictive value (PPV) of an FNA cytologic report of atypia, suspicious or positive was 0.49, 0.95 or 0.996, respectively. In the presence of a suspicious/positive report by both physical examination and mammography, the PPV of a cytologic report of suspicious was 0.99. The PPV was directly correlated with age, partly due to the incidence of fibroadenomas among younger patients; fibroadenomas were present in 53 of 146 cases with a false FNA report of atypia, in 10 of 19 cases with a false FNA report of suspicious and in 2 of 2 cases with a false FNA report of positive. Overall, 93 cases reported as benign by physical examination and mammography were biopsied on the basis of the FNA cytologic report; cancers were diagnosed in 33 of these 93 cases (6 cancers among 42 women less than 40 years old and 27 cancers among 51 women greater than 39 years old). The widespread use of FNA cytology to study breast lesions is thus recommended, without regard to patient age and even in the presence of clinically benign findings, since the increase in the rate of cancer detection is worth the excess of unnecessary biopsies. The predictive value of a positive report of FNA cytology, or even of a suspicious report in the presence of clinical suspicion, is so high that an intraoperative frozen section biopsy might be spared in such cases.