What color is breast cancer discharge?

Only about 5% of patients report having nipple discharge as one of their breast cancer symptoms.

But when they do, what does it look like? Is it always clear, or sometimes opaque? Does it ever look like breast milk? Can it be another color? And, if it’s bloody, is that a sure sign it’s breast cancer?

We went to breast surgical oncologist Ana Paula Correa Refinetti, M.D., for answers. Here’s what she wants people to know.

Most nipple discharge is benign

The first thing to know about nipple discharge is that there are two different types: 

1. Spontaneous
2. Non-spontaneous 

Spontaneous means the discharge happens without any obvious stimulation of the breast. Non-spontaneous means it happens only after the nipple is compressed in some way.

Regardless of its type, most nipple discharge is benign, says Refinetti.

“There are many benign causes of nipple discharge, including breastfeeding, pregnancy, hormonal imbalances, medications, and a normal physiological response to stimulation, even if you’re not breastfeeding. If you pinch or squeeze a nipple and a little liquid comes out, it’s a type of reflex.”

No particular color of nipple discharge is a telltale sign of breast cancer

The second thing to know about nipple discharge is that it can come in many different colors — and none of them is considered a definitive sign that you have breast cancer.

“Nipple discharge can be clear or milky, green or yellow, or even bloody,” explains Refinetti. “Most nipple discharge is non-cancerous. But we’re always going to want to do a workup on anyone who has bloody or new spontaneous nipple discharge. That’s especially true for anyone ages 40 or over, which is the recommended age for people at normal risk to start getting an annual mammogram to check for breast cancer.”

Any persistent nipple discharge needs to be investigated

You might think that yellow or green discharge is a sure sign of mastitis, which is an inflammation/infection of the breast. But that isn’t always the case. Mastitis most often occurs during breastfeeding because of a clogged duct, causing breast pain, redness, and swelling due to backed-up breast milk.

And, bloody nipple discharge should always be investigated, though it can be caused by several benign conditions, including:

• Intraductal papilloma: wart-like tumors that develop in the milk ducts; can only be diagnosed via breast biopsy
• Duct ectasia: a thickening and/or widening of the milk ducts; can only be diagnosed via mammogram or some other type of imaging

You should also see a doctor if new nipple discharge is paired with one or more of the most common breast cancer symptoms, such as:

• nipple inversion
• lump in your breast
• skin changes

“The vast majority of nipple discharges are non-cancerous,” notes Refinetti. “But that reassurance needs to come from a medical professional, not self-analysis. And any new changes that you notice in your breasts should be mentioned to your primary care provider or OB-GYN.”

Request an appointment at MD Anderson online or by calling 1-877-632-6789.