To determine the role of the use of a US-guided vacuum-assisted biopsy for the removal of sonographic evidence (excisional mammotome) for low- and high-risk benign and malignant breast lesions.

We retrospectively reviewed the pathological results of 678 excisional mammotomes (611 low- and 46 high-risk benign and 21 malignant lesions). We compared the pathological results of the excisional mammotomes and the corresponding subsequent surgery of 27 high-risk benign (7/46 cases) and malignant (20/21 cases) lesions. We also reviewed the follow-up US findings of low- (306/611 cases) and high-risk benign lesions (33/39 cases).

Fifteen of 27 (55.6%) surgical cases revealed a residual lesion on the excisional mammotome. There was no case of upgrade pathology seen for a surgical specimen. Follow-up sonography of 306 low-risk benign lesions showed a negative finding for 231 (75.2%) cases, post-biopsy changes in 56 (17.8%) cases, and residual lesions in 19 (5.7%) cases. None of the lesion was palpable. Follow-up sonography of 33 high-risk benign lesions revealed a negative finding in 28 (85%) cases, a post-biopsy scar in 4 (12%) cases, and a local recurrence in 1 (3%) case; none of the cases showed a residual lesion.

We suggest that an excisional mammotome can replace surgical excision for low-risk cases and may avoid the immediate surgery for high-risk benign lesions; however, surgery is crucial for a malignancy.