What Is Intraductal Papilloma of the Breast?

An intraductal papilloma is a type of benign (noncancerous) growth of the breast. Papillomas occur in the cells lining the milk duct (intraductal) and grow outward like a wart. The word papilloma describes the finger-like shape of the cells. Intraductal papillomas usually grow close to the nipple, but they can be found anywhere in the duct system of the breast.

Sometimes papillomas will cause nipple discharge. Discharge is bloody or clear fluid coming out of the breast.

Intraductal papilloma is not very common or dangerous. Less than 10% of benign breast lesions are a type of intraductal papilloma. Less than 1% of breast cancers are from intraductal papillomas. However, be sure to tell your healthcare provider about any lumps or nipple discharge so you can be evaluated.

This article will present an overview of the symptoms, causes, diagnosis, and treatment of intraductal papillomas in the breast.

Symptoms of Intraductal Papilloma

Symptoms of intraductal papillomas are related to the size and location of the cell growth in the breast. There are two different types of intraductal papillomas. Each has its own symptoms. Papillomatosis is a closely related condition with similar symptoms. However, papillomatosis is not the same as intraductal papilloma. 

Types and symptoms of intraductal papilloma include:

• Solitary intraductal papilloma: It is called solitary when you have just one intraductal papilloma. You may feel a lump in the center of your breast near your nipple. You may also see or experience some clear or bloody output from your nipple.
• Multiple papillomas: Multiple papillomas usually occur as a group. They are most often found in the breast’s outer (peripheral) areas. It is more common for women to feel this kind of lump. Nipple discharge is less common than with solitary intraductal papillomas. Only about 20% of patients schedule a doctor's visit because of nipple discharge.
• Papillomatosis: Papillomatosis is another noncancerous cell growth that occurs in the breast. These are groups of five or more papillomas that may occur in both breasts (bilateral). The small clumps of cells are often less clearly defined than other papillomas. They rarely cause nipple discharge.

Causes and Risk Factors

Specific causes of intraductal papilloma are not known. The cells that line milk ducts (epithelial cells) grow more than usual, but scientists do not know why. However, there are some common factors. 

Intraductal papilloma occurs most often in women. It can develop at any age but is most common in women between the ages of 35 and 55. Most of the time, it is a noncancerous (benign) condition.

Risk factors for any kind of breast tumor include:

• Birth control (contraceptive) use
• Hormone replacement therapy (HRT)
• Higher lifetime estrogen exposure
• Family history of breast cancer

How Intraductal Papilloma Is Diagnosed

If you find a lump in your breast or have nipple discharge, talk to your healthcare provider as soon as possible. Because there are many types of possible breast tumors, your healthcare provider will recommend testing and treatment based on your specific condition. While most papillomas are benign, it is important to determine if your tumor is cancerous or not. 

Your healthcare provider may order breast imaging, such as a mammogram or ultrasound. They will also check to see if you are up to date on your breast cancer screening. Some providers may recommend a clinical breast exam.

Ductogram

Your healthcare provider also may recommend a test of the milk duct system called a ductogram (also called a galactogram). This test can help find the cause of your nipple discharge. 

For a ductogram, you may be asked to squeeze a small bit of discharge from your nipple. This helps the radiologist (a doctor who uses medical imaging like X-rays) see which duct is leaking. Once the correct duct is determined, the radiologist gently inserts a fine, hollow needle into the milk duct and injects some contrast fluid into the duct network. This contrast fluid will show up on a mammogram so the doctor can see the duct system.

There are many different presentations of nipple discharge and many potential causes. A ductogram image may help identify the cause of your nipple discharge.

Biopsy

To help in diagnosis, your doctor may also order a biopsy. It is often impossible to tell if a growth is cancerous just from imaging tests like mammograms and MRI (magnetic resonance imaging).

For your biopsy, a small sample of the lump or milk duct is removed for testing in a lab to determine if the growth is cancerous. Sometimes, the fluid from the nipple discharge is also tested. One kind of biopsy procedure is called a surgical biopsy, in which the entire tumor is removed.

The American College of Radiology recommends a needle biopsy. These are less invasive, lower cost, and have fewer complications than surgical biopsy.

Treatment for Intraductal Papilloma

Depending on your biopsy results, your doctor may recommend a watch-and-wait approach (close monitoring without treatment at the current time). Other times, your healthcare team will recommend a complete cutting out (excision) of your intraductal papilloma.

Removing the tumor is a surgical procedure, but it is relatively simple and common. Most often, a small cut (incision) is made along the edge of your areola. The papilloma and the nearby milk duct are removed. A tiny scar may remain.

The two kinds of surgical treatment to remove breast tumors are:

• Lumpectomy: A lumpectomy removes the tumor and a small border around it (called the margin). The goal is to remove the abnormal growth but leave behind healthy parts.
• Mastectomy: A mastectomy is surgery to remove the whole breast. It may also include removing the nipple, chest muscles, or lymph nodes.

Your treatment team will work with you to determine what kind of removal, if any, is right for you.

Breast Cancer Risk

Your breast cancer risk is not typically increased by a solitary intraductal papilloma. However, if you have multiple papillomas or papillomatosis, your risk for developing breast cancer is slightly increased. A biopsy with any abnormal cells (called atypia) increases the risk of breast cancer.

Sometimes the biopsy shows areas of atypical hyperplasia. This is a precancerous condition in which there are extra layers of cells lining the duct, and some of the cells are irregular in shape and size.

If you have had any of these conditions, ask your healthcare provider about the recommendations you need to follow for breast cancer surveillance. You may need additional screening beyond the standard recommendations for your age.

Summary

An intraductal papilloma of the breast is a type of non-cancerous growth in the milk duct lining. A common symptom is clear or bloody discharge from the nipple. While this may appear concerning, the good news is this is rarely a sign of cancer. However, there is a small risk that it may be a more serious problem. You should contact your healthcare provider and have your breast checked. A simple needle biopsy is often all that is required to ensure that an abnormal breast lump or drainage is benign.