In this retrospective single-institution study, the upgrade rate of imaging-concordant LN with synchronous breast carcinoma was 6% (3 of 50). There was no significant difference in upgrade among patients with ipsilateral (1 of 35, 2.9%) or contralateral (2 of 15, 13.3%) carcinoma (p = 0.15). All upgraded lesions were atypical lobular hyperplasia on core needle biopsy, and all were detected as non-mass enhancement on magnetic resonance imaging (MRI). There were no significant associations of family history, menopausal status, imaging modality used to detect LN, or extent of LN on CNB with upgrade (p > 0.05).