There is no consensus regarding the management of benign papillary breast lesions diagnosed on image-guided core needle biopsy (IGCNB). This is a retrospective review of 407 patients within Kaiser Permanente Northern California diagnosed between 2012 and 2013. The study focused on patients presenting with a mass lesion and who were diagnosed with a benign papillary breast lesion (BPBL) on IGCNB. Patients who did not have surgical excision of the IGCNB papilloma were followed for at least 2 years. A total of 327 patients (80%) underwent surgical excision, 61 patients (15%) had follow-up imaging, and 19 patients (5%) had no surgery or imaging. Overall among women with surgical excision, 9.5% had a high-risk lesion, 3.4% had in situ cancer, and 2.4% had invasive cancer. An upgrade to an in situ cancer or invasive cancer was more common among women with a lesion greater than 1 cm, a palpable breast mass, age > 50 years, or if the lesion was > 5 cm from the nipple. No cancers were diagnosed in 61 women followed by imaging surveillance. This is the largest, single-cohort study of benign papillary mass lesions diagnosed on IGCNB. On surgical excision, the overall rate of upgrade to in situ cancer and invasive cancer was low, and almost all cancers diagnosed had favorable features. Because no cancers were found in women who were followed by imaging, we conclude that outcomes for BPBL diagnosed on IGCNB are favorable whether surgical excision or surveillance is the treatment choice.