ORIGINAL ARTICLE PURPOSE We aimed to estimate the upgrading rate of core-needle biopsy (CNB)-diagnosed papillary breast lesions to atypical or malignant papillary lesions on subsequent surgery. MATERIALS AND METHODSWe performed a retrospective review of medical records and imaging findings of patients diagnosed by CNB as having papillary lesions from January 1, 2005 to May 31, 2011. Outcomes were determined by pathology findings from surgical excision or by imaging findings at 12 months follow-up. RESULTSOf 130 papillary lesions in 127 patients, the upgrading rates were 0% for benign papillary lesion to malignancy, 19% for benign papillary lesion to atypical papillary lesion, and 31% for atypical lesion to malignancy. Most of the malignancies were ductal carcinoma in situ. The presence of malignant lesions was related to specific symptoms (palpable mass or nipple discharge; P = 0.020) and to a higher Breast Imaging Reporting and Data System (BIRADS) category (P = 0.017). CONCLUSION CNB is accurate in the diagnosis of benign papillary lesions. If no atypical cells are present, no malignancy is found. The presence of atypia on CNB strongly indicates a need for surgical excision.