An intraductal papilloma is a small, benign (noncancerous), wart-like growth on the lining of the milk duct that may cause nipple discharge. Intraductal papillomas are usually close to the nipple, but they can sometimes be found elsewhere in the breast. Whether you have one intraductal papilloma or several, your risk of developing breast cancer may be slightly increased.
Intraductal papilloma makes up less than 10% of benign breast lesions and less than 1% of malignant (cancerous) breast tumors.
Intraductal papillomas are different from papillary carcinoma of the breast, also known as intraductal papillary carcinoma—a rare type of breast cancer accounting for less than 1% of all invasive breast cancers.
There are two different types of intraductal papillomas, as well as one other condition that is closely related. Symptoms depend on which of these you have.
Types and symptoms:
- Solitary intraductal papillomas: If you have just one intraductal papilloma, you may feel a small lump near or just beside your nipple. When a papilloma breaks a duct, it can cause a little clear or bloody nipple discharge.
- Multiple papillomas: These consist of groups of lumps that usually occur deeper inside your breast and can’t easily be felt. Nipple discharge is less common than with solitary intraductal papillomas, occurring as the presenting complaint in approximately 20% of patients.
- Papillomatosis: Papillomatosis consists of small groups of cells inside the ducts that aren’t as distinct as papillomas. The condition usually won’t cause nipple discharge, but it can.
Anyone can develop an intraductal papilloma, but the condition is most common in women between the ages of 35 and 55. It usually develops naturally as the breast ages and changes.
If you find a small lump near your nipple or if you see some discharge, talk to your healthcare provider, but try not to panic—chances are it’s benign. Your healthcare provider will need to do a clinical breast exam and may also order breast imaging, like a mammogram or ultrasound. They will also check to see if you’re up-to-date on your breast cancer screening.
Sometimes a needle biopsy may be done to obtain a tissue sample so the fluid can be tested.
To begin this procedure, you may be asked to squeeze a small bit of discharge from your nipple, so that the radiologist can see exactly which duct is leaking. Once the duct is found, the radiologist gently inserts a very fine, hollow needle into the duct and injects some contrast fluid into the duct network. This contrast fluid will show up on a mammogram and trace the related ducts.
The resulting image may help identify the cause of your nipple discharge.
Sometimes, a ductogram or a galactogram, which are imaging studies that are done on the milk duct system, can be performed to help find papillomas.
There are many different presentations of nipple discharge, as well as many potential causes. While precancers and cancers can be the cause, they rarely are.
Intraductal papillomas can be surgically removed if they are bothersome. A small incision is made along the edge of your areola, then the papilloma and its duct are removed. The resulting scar can be nearly undetectable.
Breast Cancer Risk
Solitary intraductal papillomas don’t ordinarily increase your risk of developing breast cancer unless they contain regions of atypical hyperplasia. This is a precancerous condition where there are excess cells lining the duct, and some of the cells are irregular in shape and size.
If you have multiple papillomas or papillomatosis, your risk for developing breast cancer is slightly increased.
If you’ve had any of these conditions, ask your healthcare provider about the recommendations you need to follow for breast cancer surveillance and whether you need additional screening beyond the standard recommendations for your age.