Nipple discharge exam (nipple smear)

If fluid is coming from your nipple and staining sheets or underwear, some of the fluid may be collected and looked at under a microscope to see if any cancer cells are in it.

Most nipple discharges or secretions are not cancer. In most cases, if the fluid looks clear, green, or milky, cancer is very unlikely. If the discharge is red or red-brown, suggesting that it contains blood, it might be caused by cancer. But it is more likely caused by an injury, infection, or benign tumor.

This test may not be very helpful because even when no cancer cells are found in a nipple discharge, it doesn’t mean for certain that a breast cancer is not there. If there is a suspicious mass, a biopsy is needed, even if the nipple discharge does not contain cancer cells.