Minimizing underestimation rate of microcalcifications excised via vacuum-assisted breast biopsy: a blind study
The main disadvantage of Vacuum Assisted Breast Biopsy (VABB) is the probability of underestimating atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS). This study evaluates a modified way of performing VABB. 266 women with microcalcifications graded BI-RADS 3&4 underwent VABB (11G) on the Fischer’s table. 133 women were allocated to the “standard” protocol and 24 cores were obtained (1 offset-main target and one additional offset). 133 women were randomly allocated to the “extended” protocol and 96 cores were excised (one offset- main target and 7 peripheral offsets). A preoperative diagnosis was established, and the removed volume was calculated. When precursor or malignant lesions were diagnosed, open surgery was performed. A second pathologist, blind to the preoperative results and to the protocol made the postoperative diagnosis. The discrepancy between preoperative and postoperative diagnoses was evaluated. When the standard protocol was applied, the underestimation rate for preoperative ADH, lobular neoplasia (LN), DCIS was 16.7%, 50% and 14.3% correspondingly. In the extended protocol, no underestimation was present in LN, ADH, but the underestimation rate for DCIS was 6.3%. In the extended protocol, no precursor/malignant tissue was left after VABB in all ADH cases, in 87.5% of LN cases, in 73.3% of DCIS, and in 50% of invasive carcinomas. The volume excised was 2.33 ± 0.60 cc and 6.14 ± 1.30 cc for the standard and the extended protocol, respectively. The rate of hematoma formation did not differ between the two protocols. This recently introduced, “extended” way of performing VABB in microcalcifications safely minimizes the underestimation rate, which may lead to a modified management of ADH lesions.