Symptoms

Mammary duct ectasia often doesn't cause any signs or symptoms, but some people experience:

• A dirty white, greenish or black nipple discharge from one or both nipples
• Tenderness in the nipple or surrounding breast tissue (areola)
• Redness of the nipple and areolar tissue
• A breast lump or thickening near the clogged duct
• A nipple that's turned inward (inverted)

A bacterial infection called mastitis also may develop in the affected milk duct, causing breast tenderness, inflammation in the area around the nipple (areola) and fever.

Signs and symptoms of mammary duct ectasia may improve on their own.

When to see a doctor

Make an appointment with your doctor if you notice changes in your breasts — such as a new breast lump, spontaneous nipple discharge, skin redness or inflammation, or an inverted nipple — that are persistent or that worry you.