Purpose :The breast papillary neoplasm was constituted approximately less than 10% of benign breast tumor and 0.5-20% of breast malignancy. The role of excisional biopsy for papillary neoplasm was diagnosed by core biopsy has been debated yet. The aims of this study were to evaluate the predictive factors of breast cancer after the pathologic result of core biopsy revealed papillary neoplasm. Materials and Methods :We analyzed the clinical and pathologic data of 97 patients who underwent breast excisional biopsy after the pathologic result of core biopsy revealed papillary neoplasm between June 2009 and June 2012 at the Guro Hospital of the Korea University Medical Center. Results :We found statistically significant differences of excisional biopsy results for malignancy between papillary neoplasm and atypical papillary neoplasm diagnosed by core biopsy (P=0.001). Malignancy was found to be significantly related to be palpable mass, Breast Imaging Reporting and Data System (BIRADs) when papillary neoplasm without atypia was present in the core biopsy (P=0.03, 0.023). There were no significant differences of tumor size between benign and malignancy which was measured by ultrasonogram in the papillary neoplasm without atypia. However, there were statistically significant differences of pathologic tumor size in the papillary neoplasm without atypia (P=002). All of pathologic and ultrasonogram tumor size were larger than in the malignancy with atypical papillary neoplasm diagnosed core biopsy. In the multivariate analysis, There was significantly higher in the case of ultrasonogram measured tumor size more than 1.5cm (P=0.45, OR=2.4 95% CI 0.16-0.95). Conclusion :The excisional biopsy should be considered if the core biopsy had revealed atypical papillary neoplasm. We might suggest that excisional biopsy underwent in the papillary neoplasm without atypia with the case of the ultrasonogram measured tumor size more than 1.5cm and the existence of dis-concordance between radiologic findings and core biopsy pathologic result.