Papillary Lesions of the Breast: A Practical Approach to Diagnosis.

Papillary lesions of the breast span the spectrum of benign, atypical, and malignant. Subclassification of these lesions may be diagnostically challenging, especially with limited sampling via core biopsy. This review outlines the features of papillary lesions of the breast and provides a practical approach to distinguishing diagnostically challenging lesions by using key morphologic features and, when helpful, immunohistochemical studies.