The Incidence of Positive Margins with Breast Conserving Therapy Following Mammotome Biopsy for Microcalcification JOAN CANGIARELLA, MD, 1 * JOSHUA GROSS, MD, 2 W. FRASER SYMMANS, MD, 1 JERRY WAISMAN, MD, 1 BERT PETERSEN, MD, 3 DENNIS D’ANGELO, MD, 2 CORY SINGER, MD, 4 AND DEBORAH AXELROD, MD 5 1 Department of Pathology, New York University Medical Center, New York, New York 2 Department of Radiology, Louis Venet Comprehensive Breast Service, Beth Israel Medical Center, New York, New York 3 Department of Surgery, Louis Venet Comprehensive Breast Service, Beth Israel Medical Center, New York, New York 4 Department of Radiology, New York Presbyterian Hospital Center, New York, New York 5 Department of Surgery, St. Vincents Hospital and Medical Center, New York, New York Background and Objectives: The ability to achieve clean margins with breast conserving therapy varies greatly even when the diagnosis of car- cinoma is known beforehand. Although several reports reveal that the incidence of positive margins decreases after stereotaxic core biopsy of nonpalpable lesions and fine-needle aspiration biopsy of palpable lesions, the data on the results following mammotome biopsy (mmbx) is scanty. Methods: Two hundred and ninety-eight biopsy specimens for mammo- graphically indeterminate microcalcification from 1/97 through 3/30/98 were reviewed. Biopsies were performed using the biopsys method uti- lizing an 11-gauge multidirectional, 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 recom- mended for surgical excision. The incidence of positive margins in this subset was determined. 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 bi- opsy had definitive initial surgery with a single surgical procedure. Conclusions: Mmbx facilitates fewer surgical procedures to achieve nega- tive margins, and thus provides a better cosmetic result. J. Surg. Oncol. 2000:74:263–266. © 2000 Wiley-Liss, Inc. KEY WORDS: mammotome; stereotaxic biopsy; microcalcification; breast INTRODUCTION The ability to achieve clean margins following breast- conserving therapy varies greatly even when the diagno- sis of carcinoma is known beforehand. Several studies have shown that a preoperative diagnosis of carcinoma obtained by the use of stereotaxic core biopsy [1–3] or fine-needle aspiration biopsy [4–5] markedly reduces the incidence of positive margins at surgical excision and therefore reduces the need for re-excision [3,6,7]. There is little data on the incidence of positive margins in sur- gical excision specimens obtained following a mammo- tome biopsy diagnosis of carcinoma. We investigated the incidence of positive margins at surgical excision, in pa- tients with mammographically indeterminate microcalci- fication diagnosed with carcinoma by preoperative mam- motome biopsy. Presented in part at the Fourth Symposium on Breast Disease, Amelia Island, Florida, February 11–14, 1999. *Correspondence to: Joan Cangiarella, MD, New York University Medical Center, 530 First Avenue, Skirball West Tower, Suite 7S, New York, NY 10016. Fax: 212-263-5509. E-mail: joan.cangiarella@nyu.med.edu Accepted 27 March 2000 Journal of Surgical Oncology 2000;74:263–266 © 2000 Wiley-Liss, Inc.