14. Is Nipple Discharge Breast Cancer?
Don’t Panic. The Fluid Coming Out of Your Nipple is Most Likely Not Caused by Cancer
Nipple discharge is most often a result of non-cancerous causes. In the absence of other symptoms, including a lump in the breast, skin changes, and nipple retraction, the chances of the nipple discharge being related to cancer are small. Now that we have that out of the way, let’s talk about nipple discharge.
What is Nipple Discharge?
Nipple discharge is any fluid that comes out of the milk ducts through the nipple. This is a normal and expected occurrence during breastfeeding but may be alarming at any other time. Nipple discharge can vary widely in color, with the most common colors encountered being yellow, green, brown, white, clear, and red (or bloody). Nipple discharge can occur from one breast in multiple ducts or just one duct, or in both breasts. Finally, discharge may occur with or without nipple stimulation, including squeezing or repeated chafing from clothing. If the discharge occurs without nipple stimulation, this is referred to as spontaneous discharge. If the discharge occurs after stimulation, this is referred to as non-spontaneous discharge.
Discussing Nipple Discharge with Your Doctor
No matter the type, all patients with nipple discharge should discuss their symptoms with their primary care physician. It is always best to have your physician see and evaluate the discharge before any definitive decisions are made concerning additional tests and possible causes.
Imaging and Evaluation Protocols
Many patients will be sent for imaging of the breast to further evaluate nipple discharge. As a breast radiologist, my initial imaging protocol to evaluate nipple discharge is similar for all patients, no matter my level of concern given the type of discharge described. This protocol may vary between facilities, so please understand this is only meant to serve as a general guide.
Patients Younger than 30 Years
For patients younger than 30 years, I send the patient to breast ultrasound first where the technologist images right behind the nipple experiencing the discharge. Most women in this age group will only need a breast ultrasound; however, a mammogram may be performed in select cases depending on the ultrasound findings.
Women Between 30-39 Years
For women between 30-39 years, a diagnostic mammogram of both breasts is warranted, followed by an ultrasound behind the nipple experiencing the discharge.
Women Older than 40 Years
For women older than 40, a mammogram of both breasts is performed if it has been more than 12 months since their most recent screening mammogram. If it has been less than 12 months since their most recent screening mammogram, a mammogram only of the breast experiencing nipple discharge will be obtained. The ultrasound technologist then images the area behind the nipple experiencing the discharge.
When to Pursue Additional Imaging
If the initial imaging workup does not reveal any suspicious findings, I do not pursue additional imaging evaluation when the discharge is described as non-spontaneous (occurs only with manipulation of the nipple), occurs from both breasts, or is colored green, yellow, brown, black, or white. Although there are many causes of benign nipple discharge, one of the most common causes producing these symptoms is duct ectasia. Duct ectasia is a benign condition in which the milk ducts dilate or enlarge. Fluid may then collect within the dilated ducts. When enough fluid builds up within the duct, some of the fluid will be expressed through the nipple and is typically yellow, green, brown, or black in color. White nipple discharge often results from prior breastfeeding, even when it has been years since the woman last breastfed. If you squeeze your nipple hard enough, most women are able to express some fluid from the nipple. Just because you are able to force the liquid out does not mean that something is wrong. (I highly recommend that women DO NOT squeeze the nipple to check for discharge. This can cause irritation resulting in a small amount of bloody discharge which can confuse the picture.)
Types of Nipple Discharge That Require Additional Evaluation
However, there are several types of nipple discharge for which I will recommend additional evaluation, even when the initial imaging evaluation is negative. I am looking at all of these factors to determine if additional workup is necessary, but each characteristic alone does not hold equal weight in my determination. The nipple discharge I am most aggressive about further evaluating meets ALL of these criteria:
Factors for Further Evaluation
Color: Completely clear and colorless, or has blood in the discharge.
Spontaneous Discharge: Nipple discharge occurs without any nipple stimulation.
Occurrence: Occurs only from one breast, particularly if it occurs from a single duct from one breast.
Even nipple discharge that meets one or more of these criteria in the absence of other breast symptoms is often caused by a benign mass referred to as a papilloma. If a mass is identified on diagnostic imaging, an image-guided biopsy should be performed to make the diagnosis (I will discuss the different types of image-guided biopsies in future articles). Although papillomas are not generally malignant, making this diagnosis is important, as surgical removal of papilloma is often recommended to ensure that a small focus of cancer is not present within this usually non-cancerous mass.
Additional Imaging Methods
Additionally, a small percentage of cancers will present with the type of nipple discharge described above. Because of this, if the original imaging evaluation is negative, a breast MRI or ductography may be recommended for further evaluation of the discharge. I will discuss breast MRI in more depth in a future article, but for now, know that one of the uses of breast MRI is to further evaluate suspicious nipple discharge after a negative mammogram and ultrasound evaluation. Ductography involves placing a small specialized needle into the specific duct where discharge is expressed. Once the needle is in place, a contrast fluid is placed into the duct to distend it. Mammography and possibly ultrasound are then performed to see if an obstructing mass is present in the duct.
Although it is important to go through these steps to ensure that the discharge is not caused by a benign or malignant mass, most often nipple discharge is not something to be overly concerned about. I encourage you to discuss any new or changing breast symptoms with your primary care physician so that all breast symptoms may be thoroughly evaluated.
Written by Danielle Carroll, M.D.
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