Atypical ductal hyperplasia diagnosed at 11-gauge vacuum-assisted breast biopsy performed on suspicious clustered microcalcifications: could patients without residual microcalcifications be managed conservatively?

OBJECTIVE: The purpose of our study was to establish whether it might be safe for women with a diagnosis of atypical ductal hyperplasia (ADH) at stereotactically guided vacuum-assisted breast biopsy without any residual microcalcification after the procedure to undergo mammographic follow-up instead of surgical biopsy.
MATERIALS AND METHODS: From October 2003 to January 2009, 1173 consecutive 11-gauge vacuum-assisted breast biopsy procedures were performed. ADH was found in the specimens of 114 patients who underwent vacuum-assisted breast biopsy for a single cluster of suspicious microcalcifications smaller than 15 mm; 49 had residual microcalcifications, and 65 had microcalcifications completely removed by the procedure. Of 49 patients with residual microcalcifications, 41 underwent surgical biopsy. Of 65 patients without residual microcalcifications, 26 underwent surgical biopsy, 35 were not surgically treated and were managed conservatively with mammographic follow-up, and 4 had follow-up of less than 24 months.
RESULTS: In 41 patients with residual microcalcifications who underwent surgical biopsy, 8 malignant lesions were found at surgery. The underestimation rate was 20% (8/41). In 26 patients without residual microcalcifications who underwent surgical biopsy, no malignant lesions were found. One malignant lesion was found in the 35 patients managed conservatively at follow-up. The underestimation rate in patients without residual microcalcifications using surgical biopsy or mammographic follow-up as the reference standard was 1.6% (1/61).
CONCLUSION: Patients without residual microcalcifications after vacuum-assisted breast biopsy could possibly be managed in a conservative way with mammographic follow-up.