Flat epithelial atypia: Comparison between 9-gauge and 11-gauge devices

Background This study aimed to establish if women with a diagnosis of flat epithelial atypia (FEA) without residual microcalcifications at stereotactic vacuum-assisted breast biopsy (VABB) could be managed with mammographic follow-up (FU) instead of surgery and to compare 9-gauge and 11-gauge devices. Patients and Methods From October 2003 to January 2011, 2382 VABB procedures were performed (1373 with 11-gauge and 1009 with 9-gauge). We found 121 cases of pure FEA that were surgically treated: 57 with a 9-gauge device (group 1) and 64 with an 11-gauge device (group 2). The underestimation rate (UR) of malignancy for patients without and those with residual microcalcifications for each VABB device was calculated. Differences between groups were analyzed with the Fischer exact test. Results The overall UR of FEA was 4% (2 of 57) with the 9-gauge device and 8% (5 of 64) with the 11-gauge device. With a 9-gauge device, the UR for patients without residual microcalcifications was 0% (0 of 46), and the UR for patients with residual microcalcifications was 18% (2 of 11). With an 11-gauge device, the UR for patients without residual microcalcifications was 0% (0 of 39), the UR for patients with residual microcalcifications at post-biopsy mammograms was 16% (5 of 25). With a 9-gauge device, 80% (46 of 57) of patients did not have residual microcalcifications after VABB. With an 11-gauge device, 60% (39 of 64) of patients had no residual microcalcifications after VABB. Differences between the 9-gauge and 11-gauge devices were statistically significant (P