Papillary lesions of the breast diagnosed by core needle biopsy: 71 cases with surgical follow-up

Background: Papillary breast lesions comprise a spectrum of histopathologic diagnoses ranging from benign papillomas to papillary carcinomas. There is ongoing controversy regarding the management of papillary lesions diagnosed by core needle biopsy (CNB). Some authors advocate observation of papillary lesions when the CNB is benign, while others recommend surgical excision of all papillary lesions. The current study assessed the adequacy of CNB in evaluating papillary breast lesions. Methods: A search of the pathology database at our institution identified 122 papillary lesions diagnosed by CNB. The study population consisted of 71 papillary lesions that were subsequently surgically excised. Results: Of the 71 papillary lesions excised, 8 were malignant, 16 were atypical, and 47 were benign at the time of CNB. Of the 47 papillary lesions thought to be benign, 13 (28%) revealed atypia and 4 (9%) revealed malignancy upon surgical excision. Of the 13 atypical papillary lesions on CNB, 7 lesions (54%) were associated with malignancy upon excision. Slightly over half the upgrades were due to finding atypia or malignancy in the tissue surrounding the papillary lesion. The total rate of upgrades from the CNB diagnosis to the excisional diagnosis was 38%. Conclusions: When a core biopsy of a papillary lesion is encountered, there is a strong likelihood of discovering atypia or malignancy in the index lesion or in close proximity. Therefore, surgical excision should be performed to avoid missing a malignancy and to allow for accurate breast cancer risk assessment that can impact survival and decisions regarding chemoprevention.