Diagnostic accuracy of vacuum-assisted biopsy device for image-detected breast lesions

Background: Non-palpable breast lesions present diagnostic difficulties. Ultrasound-guided fine-needle aspiration cytology (FNAC) is a common method used to obtain a diagnosis, but FNAC is frequently inconclusive or insufficiently accurate. Recently a vacuum-assisted biopsy device (Mammotome((R)), Ethicon, Endo-surgery, USA) has been introduced. The diagnostic accuracy of this biopsy device was assessed for lesions that were visible on ultrasound. Methods: Fifty ultrasound-guided mammotome biopsies were performed. All were small breast lesions primarily detected by ultrasound. All received FNAC as initial assessment. Mammotome biopsy was performed whenever the breast lesion was considered indeterminate or if it was considered benign and there were associated risk factors such as a family history of breast cancer. Results: Of 50 mammotome biopsies 45 had benign histology. Three of 45 lesions were excised at the patients' request and were confirmed to be benign. The remaining 42 patients received an ultrasound follow up at 6 months. The lesion size remained static in 39 patients. In three patients the lesion size increased and they were excised and histology was benign. For the four malignancies diagnosed with mammotome biopsy, three patients received definitive treatment and one patient defaulted. There was one failed mammotome biopsy in the present series. Conclusions: Mammotome biopsy is an acceptable diagnostic method for small breast lesions seen on ultrasound. It reduces the need for open biopsy without compromising diagnostic accuracy.