Definition

A benign (not cancer) condition in which a milk duct under the nipple widens and thickens. This can cause the milk duct to become blocked and fluid to build up inside it. There are usually no symptoms, but sometimes there may be a thick nipple discharge or redness or tenderness of the nipple and nearby breast tissue. Mammary duct ectasia is most common in women who are near menopause or have gone through it. Also called breast duct ectasia.