Characterization and outcome of breast needle core biopsy diagnoses of lesions of uncertain malignant potential (B3) in abnormalities detected by mammographic screening.

In the setting of breast cancer screening, 5-9% of needle core biopsies are diagnosed as lesions of uncertain malignant potential (B3). The management of these lesions is potentially problematic as the data on their outcome remains limited. In our study, we aim to assess the outcome of screen-detected lesions diagnosed as B3 in a large series to validate previous studies and to characterize the malignant lesions detected after a B3 diagnosis.