Absence of Residual Microcalcifications in Atypical Ductal Hyperplasia Diagnosed via Stereotactic Vacuum-Assisted Breast Biopsy: Is Surgical Excision Obviated?

PURPOSE: The purpose of our study was to evaluate the underestimation rate of atypical ductal hyperplasia (ADH) on vacuum-assisted breast biopsy (VABB), and to examine the correlation between residual microcalcifications and the underestimation rate of ADH. METHODS: A retrospective study was performed on 27 women (mean age, 49.2±9.2 years) who underwent additional excision for ADH via VABB for microcalcifications observed by using mammography. The mammographic findings, histopathologic diagnosis of all VABB and surgical specimens, and association of malignancy with residual microcalcifications were evaluated. The underestimation rate of ADH was also calculated. RESULTS: Of the 27 women with microcalcifications, nine were upgraded to ductal carcinoma in situ (DCIS); thus, the underestimation rate was 33.3% (9/27). There was no difference in age (p=0.40) and extent of microcalcifications (p=0.10) when comparing benign and malignant cases. Six of 17 patients (35.3%) with remaining calcifications after VABB were upgraded to DCIS, and three of 10 patients (30%) with no residual calcifications after VABB were upgraded (p=1.00). CONCLUSION: The underestimation rate of ADH on VABB was 33.3%. Furthermore, 30% of patients with no remaining calcifications were upgraded to DCIS. Therefore, we conclude that all ADH cases diagnosed via VABB should be excised regardless of the presence of residual microcalcifications.