The mammotome(MMT) biopsy is a new surgical technique that is a minimally invasive, image guided procedure, and it requires just one small incision and there is no need for multiple insertions in the breast. The aim of this study was to evaluate the efficacy and the safety of the MMT biopsy device for percutaneous removal of breast masses with using ultrasound guidance.

From Jan. 2003 to Mar. 2005, a total of 1368 US-guided excisional MMT biopsies were preformed in 1112 patients at Kangnam Cha Hospieal Those lesions with BI-RADS category 3and 4a features by USG examination were included in this study. Lesions below 1.0cm were removed by an 11G probe, and lesions above 1.0cm were removed by an 8G probe. Ultrasonographic follow-ups were performed 3-6 months later to assess the residual tissue and scarring.

The mean patient age was 36 (range: 14-76)years. The average size of lesion was 1.14cm (SD = 0.63cm). Among the patients, 67.3% had nonpalpable lesion and 32.7% had palpable tumor. Themajority of the specimens(98.3%) were benign. Most of benign specimens(77.7%) consisted of fibroadenoma and fibrocystic changes, although 23 lesions(1.7%) were malignant. The mean MMT procedure time was 6.2±3.9 minutes and the mean number of cores removed was 14.8±9.8. No serious bleeding or infection occurred post-operatively.

This study demonstrates that percutaneous breast biopsy using the MMT system may be feasible and effectivemethod for the diagnostic and therapeutic management of benign breast lesions with minimal morbidity. Complete MMT excision may be safely performed for the lesions those are less than 3cm in size. A breast surgeon can use MMT instead of open or core needle biopsy for the initial biopsy of breast lesions.