Duct Ectasia

Duct ectasia, also known as mammary duct ectasia or periductal mastitis, is a benign (non-cancerous) breast condition that occurs when a milk duct in the breast widens and its walls thicken. This can cause the duct to become blocked and lead to fluid build-up. It’s more common in women who are getting close to menopause. But it can happen after menopause, too.


Often, this condition causes no symptoms and is found when a biopsy (removing a piece of tissue to checked under a microscope) is done for another breast problem.

Less often, duct ectasia may cause a sticky green or black nipple discharge, which is often thick. The nipple and nearby breast tissue may be tender and red. The nipple may be pulled inward. Sometimes scar tissue around the abnormal duct causes a hard lump that may be confused with cancer. An ultrasound and/or mammogram may be done to learn more about the changed part of your breast.

If there’s a lump, a biopsy may be needed to make sure it’s not cancer. A hollow needle is used to take a tiny piece of tissue from the area so it can be checked in the lab for cancer cells.


Duct ectasia sometimes gets better without treatment. Warm compresses and antibiotics may be used in some cases. If the symptoms do not go away, the abnormal duct may be removed with surgery.

How does duct ectasia affect your risk for breast cancer?

Duct ectasia does not increase your breast cancer risk.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Collins LC, Schnitt SJ. Chapter 9: Pathology of benign breast disorders. In: Harris JR, Lippman ME, Morrow M, Osborne CK, eds. Diseases of the Breast. 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2014.

Last Medical Review: September 20, 2017 Last Revised: September 20, 2017

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