Stereotactic fine-needle aspiration for cytologic diagnosis of nonpalpable breast lesions.

Fine-needle aspiration for cytologic diagnosis was performed on 219 nonpalpable breast lesions by using a stereotactic localization technique. Cytologic results were correlated with mammographic findings, and therapeutic decisions were based on the results of both procedures. Representative cytologic material was obtained in 74% of the lesions. Strict criteria of representativeness were observed. If only cases with representative cytologic yield are considered, the sensitivity was 93% and the specificity was 97%. The predictive values were high except for the predictive value of a negative cytologic finding in a spiculated lesion (50%). Sampling errors caused by abundant fibrosis, needle deviation, and difficulty in defining the lesion on the stereoscopic views are discussed. Another source of sampling error may be the mixed nature of some lesions consisting of benign and malignant components. Fine-needle aspiration of 219 nonpalpable breast lesions by using a stereotactic localization device yielded representative cytologic samples in 74% of the lesions.