Stereotactic Vacuum-Assisted Breast Biopsy Is Not a Therapeutic Procedure Even When All Mammographically Found Calcifications Are Removed: Analysis of 4,086 Procedures

OBJECTIVE. The purpose of our study was to assess whether in case of total removal of microcalcifications there is still residual tumor on the surgical specimen and, secondarily, to assess whether complete rather than partial excision of the imaging target with microcalcifications may result in increased diagnostic accuracy. MATERIALS AND METHODS. We retrospectively reviewed 4,086 stereotactic vacuum-assisted breast biopsy (VABB) procedures for microcalcifications and histologic findings to determine the frequency of malignancy, histologic underestimation, and complete removal of cancer. RESULTS. No residual microcalcifications on postbiopsy mammograms were seen in 1,594 of 4,047 (39.4%) procedures successfully completed: 351 of 1,594 lesions were malignant, 1,109 benign and 134 atypical. After partial removal of microcalcifications at VABB, the postsurgical specimen had infiltrating carcinoma in 130 of 566 cases (23%), whereas in case of total removal of microcalcifications, the underestimation occurred in 13 of 234 (5.5%) cases. The atypical ductal hyperplasia underestimation rate was 6.6% when the mammography target was completely removed and 38.7% when the target was only sampled. The percentage of lobular carcinoma in situ underestimation was the same for the two groups with partial and total removal of microcalcifications (21.2%). Among 1,016 VABB procedures with pathologic result of malignancy, 882 (86.6%) had residual cancer at surgery. In the group with complete removal of microcalcifications at VABB, residual cancer was found in 70% of cases. CONCLUSION. VABB may not be considered a therapeutic procedure, even in the case of complete removal of microcalcifications. However, a complete removal of microcalcifications may result in low rates of underestimation of malignancy and may consequently increase the diagnostic accuracy of the diagnostic procedure.