Does Initial Imaging Modality Affect Breast Biopsy Upgrade Rates? A Single Institution Review.

INTRODUCTION: Image-guided core needle biopsy (CNB) is the standard for diagnostic breast biopsy. However, the upgrade rate to a higher order lesion defined as identification of malignancy on final pathology from surgical excision remains problematic.

MATERIALS AND METHODS: A retrospective chart review of all core needle biopsies from 2008 to 2012 was performed. We identified lesions demonstrating atypia without associated malignancy on core needle biopsy and recorded multiple factors to evaluate predictors of upgrade.

RESULTS: Of 151 independent core needle biopsies recorded, 26.5% were upgraded to a higher order lesion. Concurrent mammogram and ultrasound (US) were associated with higher sampling error than any individual imaging modality (P = .021). MRI had a trend toward lower rate of upgrade rate but did not reach statistical significance.

DISCUSSION: Although MRI had a lower rate of upgrade rate due to sampling error, this did not reach significance possibly because of our small sample size.