Clinical history: 48 year old female with nipple discharge.
What is the most probable diagnosis?
Benign Intraductal Papilloma
The first picture shows a section from an excised intraductal papillary lesion with focal giant cell reaction from previous biopsy. On higher magnification the fibrovascular cores can be seen to be lined by myoepithelial cells and unremarkable epithelial cells. There is no hyperplasia or atypia. These features are consistent with an intraductal papilloma.
Intraductal papillomas are benign lesions, generally < 1cm in diameter, that are adequately treated by excision. They can be distinguished into two groups: central papillomas (involving large ducts) and peripheral papillomas (involve terminal duct lobular units). Central papillomas are usually solitary, while peripheral ones are more commonly multiple. Central papillomas most frequently present with bloody nipple discharge in patients from 30-50 years old. In problematic cases the myoepithelial cell layer can be highlighted by immunostaining for actin, calponin, p63, CD10, or other myoepithelial cell markers.