The substantial majority of questionable lesions detected by mammography are benign, and there is growing interest among health care professionals and patients in alternatives to surgical biopsy for diagnosing theselesions. Stereotactic breast biopsy is an x-ray guided method forlocalizing and sampling breast lesions discovered on mammography andconsidered to be suspicious for malignancy. Its use in sampling small, nonpalpable breast lesions has been investigated over the past 15 years, using fine-needle aspiration for cytology and, more recently, core-needlebiopsy for histology. Multiple series comparing stereotactic biopsy withsurgical biopsy have shown that stereotactic techniques accurately samplesmall lesions and have a sensitivity of 90 to 95 percent for breast cancerdetection. State-of-the-art stereotactic breast biopsy is comparable insensitivity to surgical biopsy, and the procedure is quicker, cheaper, andeasier than the standard practice of preoperative, mammographically guidedlocalization followed by surgical biopsy. In an age of miniaturization, stereotactic techniques provide miniature breast biopsies.

The University of Chicago acquired the first prone stereotactic table in the United Statesin 1986, and we have found stereotactic breast biopsy to be a very goodalternative for certain lesions that would otherwise require surgicalbiopsy for diagnosis. Most lesions (70 percent) sent to conventional biopsyat the University of Chicago between 1986 and 1989 were graded by observersas being in a low-suspicion category (less than 10 percent chance ofmalignancy based on mammographic findings), and the positive malignancyyield of this category of lesions was seven percent. These lesions werealso examined with stereotactic fine-needle aspiration performed as a “piggy-back” procedure to the needle localization for surgery. The resultsof this study have led us to use stereotactic biopsy rather than surgicalbiopsy for low-suspicion lesions since then. We currently use stereotacticbreast biopsy for about half the nonpalpable lesions considered for breastbiopsy at our institution and find it to be reliable and readily acceptedby informed patients.

The introduction of automated core-biopsy guns hasescalated interest in the technique, due to increased confidence in thehistologic samples obtained and the ability to make specific benigndiagnoses more frequently. Some centers have extended the potential use ofstereotaxis to virtually all suspicious mammographic lesions, includingthose with a high probability of malignancy, to plan definitive surgery.Based on current estimates, there are now over 1,000 centers eitherinvestigating or using stereotactic biopsy for occult breast lesions.