Intraductal papillomas of the breast are benign lesions with an incidence of approximately 2-3% in humans.

[1] They result from abnormal proliferation of the epithelial cells lining the breast ducts.

[2] Two types of intraductal papillomas are generally distinguished.

[3] They are the most common cause of bloody nipple discharge in women age 20-40 and generally do not show up on mammography due to their small size.

[4] Microdochectomy/microdochotomy (removal of a breast duct) is the treatment of choice.