LCNB findings of carcinoma are accurate and allow definitive therapeutic surgery, including mastectomy. LCNB findings of ADH are inaccurate, and excisional biopsy is necessary.

The false-negative rate with LCNB was 1.2% in this study and 4.0% in the literature. The presence of carcinoma in ADH and radial scar lesions was often underestimated.

Unsuccessful NLBB was more likely with two lesions per breast, small lesions, small specimens, and microcalcifications. Piercing such lesions with the localizing needle led to successful biopsy. Removal of more tissue was helpful with missed microcalcifications.

False-negative findings at stereotactic biopsy were least common with 11-gauge probes and were similar in frequency for calcifications and masses.

RogerJ.FrancisA. Marzoni,Jr.2 KentW. Nowels3OBJECTIVE. The purposeof our studywas to evaluatehow often histologicallybenign lesions were completely removed as shown by the initial mammogram after biopsy. We corn pared three percutaneousbiopsy techniques.MATERIALS AND METHODS. Retrospective review wasperformedon 1206 consec utive impalpable breast lesions having percutaneous stereotactic biopsies done on a prone bi opsy table using 14-gauge automated large-core needles (n = 721); 14-gauge directional vacuum-assisted probes (n = 192); and 1I-gauge directional vacuum-assisted probes (n = 293). Lesions that were histologically benign and that did not have subsequent surgical cxci sion had mammographic follow-up. The 667 initial mammograms after biopsy (advised to be doneat 6 or 12 monthsand accomplishedat 1â€"53 months[median,7 months]after biopsy) were reviewed to see if the lesions were no longer apparent.RESULTS. The lesion was absentin 9% (40/422) of lesionsfor which 14-gaugelarge core biopsy was used, 22% (21/95) of lesions for which 14-gauge vacuum-assistedbiopsy was used, and 64% (96/150) of lesions for which I I-gauge vacuum-assisted biopsy was used