Mammary duct ectasia (ek-TAY-zhuh) occurs when a milk duct beneath your nipple widens, the duct walls thicken and the duct fills with fluid. The milk duct may become blocked or clogged with a thick, sticky substance. The condition often causes no symptoms, but some women may have nipple discharge, breast tenderness or inflammation of the clogged duct (periductal mastitis).
Mammary duct ectasia most often occurs in women of perimenopausal age â around 45 to 55 years â but it can happen after menopause, too. The condition sometimes improves without treatment. If symptoms persist, you may need antibiotics or possibly surgery to remove the affected milk duct.
Though it's normal to worry about any changes in your breasts, mammary duct ectasia and periductal mastisis aren't risk factors for breast cancer.