The incidence of positive margins with breast conserving therapy followingmammotome biopsy for microcalcification

Background and Objectives: The ability to achieve clean margins with breast conserving therapy varies greatly even when the diagnosis of carcinoma is known beforehand. Although several reports reveal that the incidence of pos itive margins decreases after stereotaxic core biopsy of nonpalpable lesion s and fine-needle aspiration biopsy of palpable lesions, the data on the re sults following mammotome biopsy (mmbx) is scanty. Methods: Two hundred and ninety-eight biopsy specimens for mammographically indeterminate microcalcification from 1/97 through 3/30/98 were reviewed. Biopsies were performed using the biopsys method utilizing an 11-gauge mult idirectional, vacuum-directed device. Results: Ten percent (n = 31) of the mammotome biopsies were atypical and 9 % (n = 27) were malignant. These 58 cases (19%) were recommended for surgic al excision. The incidence of positive margins in this subset was determine d. Of patients who underwent lumpectomy as their initial surgical procedure 69% had negative surgical margins. Seventy-seven percent of patients with carcinoma diagnosed by mammotome biopsy had definitive initial surgery with a single surgical procedure. Conclusions: Mmbx facilitates fewer surgical procedures to achieve negative margins, and thus provides a better cosmetic result. (C) 2000 Wiley-Liss, Inc.