Mammotome biopsy: impact on preoperative diagnosis rate

AIM: To assess the impact of mammotome biopsy on preoperative diagnosis rate. METHODS: A prospective study was undertaken to examine the referral patterns, radiological abnormalities, sensitivity, specificity and outcome of the first 150 patients undergoing mammotome biopsy at our institution. Most of the referrals were from the NHS Breast Screening Programme (85/100). RESULTS: The commonest radiological abnormality was microcalcification (87%). The accuracy of this biopsy technique for the target lesion was over 99%. Post-biopsy, 11 patients needed to proceed to a diagnostic surgical biopsy (7%). Forty-two malignancies were identified at final histology; 41 were diagnosed preoperatively. The positive predictive of mammotome biopsy was 98% for the present study. The present results for mammotome biopsy with regard to predicting invasion were: sensitivity 71.4% (10/14); specificity 100% (0/0); positive predictive value 100% (10/10); and negative predictive value 87% (27/31). CONCLUSION: Prone mammotome biopsy has proven to be highly accurate, considerably improving the preoperative diagnosis within our unit, and obviating the majority of diagnostic excision biopsies. (c) 2005 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.