24th May 2025

Intraductal Papilloma

Intraductal papillomas are the most common cause of pathological nipple discharge, classically seen in women between the ages of 40 and 50 years. They are characterised by the development of a wart-like lump within the milk ducts and are usually found in the vicinity of the nipple, though they can occur anywhere in the breast. Central intraductal papillomas, located in the subareolar region, arise from large lactiferous ducts and are usually solitary in nature. Peripheral intraductal papillomas meanwhile, involve the terminal duct lobular unit (TDLU) and are usually several in number, termed papillomatosis.

As papillomas can be asymptomatic, they are often noted incidentally during routine imaging. However, clinical examination may reveal a painless retroareolar mass. In instances of nipple discharge, papillomas are typically associated with unilateral, spontaneous and persistent discharge of bloody or serosanguinous fluid, often less than 6 months in duration. 

Mammography is usually normal, though findings may include a solitary or multiple dilated ducts, with an associated subareolar mass that is benign in appearance, with or without calcification. On ultrasound, a papilloma can be seen as a well-defined mass, partially outlined by fluid, with colour doppler demonstrating a vascular stalk. Further investigation is usually warranted, usually by way of an excision biopsy, which reveals a dual population of both epithelial and myoepithelial cells lining a fibrovascular core and set within a duct.

Papillomas are not associated with an increased risk of breast cancer, unless they are noted to contain atypical cells during histological assessment. Follow-up is typically reserved for those in which atypical cells have been identified, or those with multiple papillomas.