Outcome of Non-Malignant Papillary Lesions of the Breast on Core Biopsy: An Experience from a Tertiary Care Center in Pakistan

Background Papillary lesions of the breast constitute a heterogeneous group ranging from non-malignant papillomas to papillary carcinoma. While surgical excision is recommended for atypical papilloma or papillary DCIS/ carcinoma on core biopsy, controversy persists in the management of benign papillomas which are diagnosed with core needle biopsy (CNB) since there are variable reported rates for tumor upgrade. The purpose of this study was to determine the outcome of papillary lesions of the breast diagnosed at image-guided CNB, after surgical excision or follow-up, and to identify potential predictors of high-risk lesions/malignancy on imaging. Materials and methods We retrospectively identified 52 non-malignant papillary lesions on core biopsy between January 2012 and June 2018. The outcome of surgical excision, as well as clinical and imaging features of these lesions, were assessed. The final histologic upgrade was recorded, and variables were compared between benign and atypical lesions on core biopsy as well as between upgraded and non-upgraded lesions after surgical excision. Results Thirty-six lesions out of 52 lesions were benign papillomas on core biopsy, while 16 were papillary lesions with ADH/DCIS. All of these lesions except four benign papillomas were excised. Of the 32 benign papillomas excised, 7 were upgraded to papilloma with ADH/DCIS and one to DCIS with the focus of invasion. Among the 16 atypical lesions excised, one was upgraded to papillary DCIS with a final upgrade rate of 17.3%. There was no statistically significant clinical or imaging feature among those that were upgraded on excision from those that were not upgraded. Conclusion Non-malignant papillary lesions have a significant upgrade rate. There are no reliable clinical or imaging features that can pre-surgically predict upgrade. Therefore, surgical excision of all papillary lesions is recommended for definitive diagnosis.