Stereotactic fine-needle aspiration cytology of nonpalpable breast lesions: initial experience in a tertiary-care institution.

To assess the accuracy of stereotactic fine-needle aspiration cytology in the diagnosis of nonpalpable breast lesions, this procedure was performed in 226 consecutive patients, all women, immediately before needle localization and excision of the lesions. The patients were treated at a tertiary-care hospital between December 1989 and October 1991. The cytologic results (lesion benign, atypical, suspicious or malignant or insufficient material for interpretation) were compared with the histologic findings and the degree of suspicion (low, slight or high) on the basis of mammographic examination. The aspiration procedures were successful in only 159 patients (70.4%), and for 155 of these, histologic findings were available for correlation. The number of unsatisfactory specimens in this group was large: 65 of 155 (42%). When unsatisfactory specimens were included in the calculations and a cytologic finding of a suspicious or malignant lesion was treated as positive, the sensitivity of fine-needle aspiration cytology for malignancy was 23% (8/35) and the specificity 53% (63/120). The positive and negative predictive values were 89% (8/9) and 78% (63/81) respectively. A cytologic finding that the lesion was benign was unreliable in lesions for which the mammographic suspicion of malignancy was slight or high (4 of 30 malignant lesions with slight mammographic suspicion and 4 of 7 with high mammographic suspicion were classified as benign on the basis of the cytologic examination). Of the 24 cases with atypical cytologic findings, 10 involved malignancy.(ABSTRACT TRUNCATED AT 250 WORDS)