An intraductal papilloma is a benign tumor that develops inside the breast duct. Peripheral intraductal papillomas are the same type of growth as a central intraductal papilloma. They tend to have a tan or pink appearance, and under the microscope they contain multiple finger-like projections. The main difference is that instead of growing under the nipple, they grow in the terminal ducts. These ducts are farther up the breast structure and closer to the milk-producing lobules.
Other frequent differences versus central intraductal papillomas are that:
- Multiple papillomas are more common with peripheral papillomas, and they can appear in both breasts (bilateral).
- Peripheral papillomas tend to be even smaller in size than a central papilloma and may be less likely to cause discharge.
- They tend to affect younger, premenopausal women.
Peripheral papillomas appear to slightly increase the risk of breast cancer. In some cases, breast cancer cells are actually found close to peripheral papillomas. Your doctor would remove any papillomas or the ducts that contain them. A pathologist (a doctor who examines cells) then examines the tissue to make sure everything checks out okay.
Sometimes, a papilloma may contain abnormal-looking cells that resemble atypical ductal hyperplasia (which carries a moderate increase in breast cancer risk) or even low-grade ductal carcinoma in situ.