A nipple discharge is often a normal finding. Many premenopausal women are able to express fluid from the nipple. These benign or physiologic nipple discharges are typically non-spontaneous, meaning one has to press or squeeze the nipple for the discharge to come out. They are typically multicolored: greenish, gray, white. The usually can be produced from both breasts and come out of multiple duct openings on the surface of the nipple. Physiologic nipple discharges are usually not associated with other findings on clinical breast examination or mammogram.
Certain characteristics raise the possibility that a nipple discharge is a sign of cancer. Spontaneous discharges which come out without any pressure on the breast are more suspicious. They may be seen staining the inside of a bra or other clothes. The color of the discharge is significant: clear watery, clear yellow (serous), blood-tinged (serosanguinous) or bloody nipple discharges are more concerning. Other factors include a discharge from only one breast, particularly if it comes out of a single opening on the nipple, or if there is a trigger point: pressure on one particular part the areola produces the discharge. A nipple discharge in a woman who is either over 50 years old or postmenopausal is significant. A discharge associated with an underlying mass on clinical breast examination or a mammographic abnormality is more likely to be caused by breast cancer.
If you have a nipple discharge, you should see your doctor for an evaluation, particularly if it is spontaneous, comes from a single duct, is bloody clear or yellow, is associated with a lump, you are >50 or postmenopausal, or the discharge persists after your next menstrual cycle if you are premenopausal.
You may be referred to a breast surgeon for an evaluation. Your doctor or breast surgeon will take a detailed history about the characteristics of the discharge, any other breast symptoms, breast cancer risk factors and general medical history. A clinical breast examination will be performed. For a woman who is thirty or old with a nipple discharge, a mammogram will usually be done, not only to get more information about the discharge, but also to be see if any other findings have developed elsewhere in either breast. If the discharge is clinically significant, an ultrasound can be performed to see if the underlying cause of the discharge can be identified, such as benign findings like cysts or duct ectasia. If a solid mass is seen on ultrasound, a biopsy of the mass can be performed. A sample of discharge fluid can be sent for analysis, but is not necessarily helpful since it will appear normal in 50% of nipple discharges associated with breast cancer. If the discharge is clinically significant, but there are no findings on ultrasound, a ductogram (galactogram) may be performed; a tiny catheter is inserted in the duct opening on the surface of the nipple where the discharge emanates, a small amount of dye is injected and a mammogram is performed. This creates a picture of the underlying ducts to see if there are any intraductal masses or blockages which could be the source of the nipple discharge. Sometimes a specific type of breast biopsy called a duct excision is performed to make a diagnosis. With this surgical procedure, dye is injected or a probe inserted into the duct opening, a small incision is made along the edge of the areola and the ducts associated with the discharge are removed. Many clinically significant discharges are caused by benign intraductal papillomas. Unfortunately needle biopsies cannot distinguish benign papillomas from papillary breast cancer, so if it appears likely that the discharge is caused by a papilloma, a surgical biopsy could be considered to avoid a two-step evaluation with both needle biopsy and surgical biopsy.