Objective: The aim of our study was to determine the false-negative rate of stereotactic 11-gauge vacuum-assisted biopsy in a validation study of lesions that had subsequent surgical excision.
Materials and methods: Retrospective review was performed of 318 lesions that underwent stereotactic 11-gauge vacuum-assisted biopsy and subsequent surgical excision. A false-negative case was defined as a pathologically proven cancer in which stereotactic biopsy yielded benign results without atypia. Medical records, imaging studies, and histologic findings were reviewed.
Results: False-negative findings were encountered at stereotactic 11-gauge vacuum-assisted biopsy in 3.3% (7/214) of pathologically proven cancers. False-negative findings occurred in 3.5% (4/115) of malignant calcification lesions versus 3.0% (3/99) of malignant masses (p = 1.0). The seven false-negative findings included five Breast Imaging Reporting and Data System (BI-RADS) category 5 lesions that yielded benign results at biopsy, one BI-RADS category 4 mass that benign breast tissue, and one BI-RADS category 4 cluster of calcifications in which no calcifications were retrieved. The false-negative rate was 10.0% (6/60) for radiologists who performed 15 or fewer previous stereotactic vacuum-assisted biopsy procedures versus 0.6% (1/154) for radiologists who performed more than 15 previous stereotactic vacuum-assisted biopsy procedures (p = 0.002).
Conclusion: Stereotactic 11-gauge vacuum-assisted biopsy had a false-negative rate of 3.3% that diminished to 0.6% with experience. All false-negative findings could be prospectively identified because of failure to sample calcifications or imaging-histologic discordance.