Papillary Neoplasms of the Breast: WHO Classification, Multimodality Imaging, and Radiologic-Pathologic Correlation.

The fifth edition of the World Health Organization Classification system for breast tumors defines five distinct categories of papillary breast neoplasms characterized by papillary architecture composed of arborizing fibrovascular cores. The lesions span a wide spectrum of benign, atypical, and malignant neoplasms classified based on the nature of proliferating epithelial cells and the presence or absence of basal myoepithelial cells. The pathologic diagnosis of different papillary lesions on the basis of core needle biopsy can be challenging due to limited tissue sampling, artifacts, and overlapping morphologic features and immunohistochemical staining patterns. A distinction must be made between noninvasive and invasive forms of malignant papillary tumors because the prognostic staging and clinical management differ. A recent paradigm shift in management strategy favors a more conservative approach of surveillance rather than routine surgical excision for benign intraductal papillomas without atypia. The authors provide an overview of the various papillary lesions of the breast and their WHO classification. A description of the clinical, multimodality imaging, and histopathologic features is provided, along with an illustrative review of radiologic-pathologic correlation. Understanding the histologic and biologic spectrum of papillary lesions and radiologic-pathologic correlation is key for clinical management. ©RSNA, 2025 Supplemental material is available for this article.