To review papillary lesions of the breast, including clinical presentation, imaging and pathologic findings. To illustrate imaging findings (mammogram, US, ductography, MR), interventional procedures and pathologic correlation. To analyze current concepts in papillary lesions, including diagnostic (imaging and pathologic) and management difficulties. To emphasize pitfalls and differential diagnosis.

Papillary lesions of the breast are an heterogeneous group, with similar and differential features. They may be benign, atypical, in situ or invasive or, to describe it in a way, "something" among all types, a combination of features. Both imaging findingsand pathologic analysis pose a challenge in diagnosis. Management of papillary lesions diagnosed on biopsy is not always clear regarding whether even benign lesions need excision. We review current concepts on papillary lesions and recommendations for clinical practice.

1. Definition. A papillary lesion consists of a frond-forming growth patterncomposed of fibrovascular stalks (Fig. 1) covered by a layerof epithelial cells with or without an intervening myoepithelial cell layer. 2. Clinical presentation. Patients with papillary lesions may present with: Nipple discharge.Suspicious discharge is spontaneous, serous or bloody and is coming from a single duct. Cytology may depict papillary groups (Fig. 2 ). Palpable mass. Most frequently central. Sometimes they are asymptomatic. 3. Pathology classification. The classification for papillary lesions includes a wide range from...

Papillary lesions of the breast may be benign, atypical, in situ or invasive.Imaging findings are non-specific, most frequently a mass within a cyst or duct. Pathologic diagnosis is sometimes also difficult. Management of benign lesion, whether excision or follow-up should be performed is still a matter of discussion.

Yamaguchi R, Tanaka M, Tse G M, Yamaguchi M, Terasaki H, Hirai Y, Nonaka Y, Morita M, Yokoyama T, Kanomata N, Naito Y, Akiba J, Yano H.Management of breast papillary lesions diagnosed in ultrasound-guided vacuum-assisted and core needle biopsies.Histopathology 2015:66;565–576. Sheiman LS, Levesque PH. The In's and Out's of Ductography: A Comprehensive Review. Curr Probl Diagn Radiol. 2015 Jun 5. pii: S0363-0188(15)00087-0. doi: 10.1067/j.cpradiol.2015.05.007. [Epub ahead of print]. Nicholson BT, Harvey JA, Patrie JT, Mugler JP . 3D-MR Ductography and Contrast-Enhanced MR Mammography in Patients...