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Diseases and Conditions
Mammary duct ectasia
From MayoClinic.com
Special to CNN.com


Your breasts are made up of connective tissues that include a system of milk ducts — tiny passages that carry milk to the nipples. Mammary duct ectasia occurs when a milk duct beneath the nipple becomes dilated and filled with fluid. The milk duct can then become blocked or clogged with a thick, sticky substance. Though it's normal to worry about any changes in your breasts, mammary duct ectasia is not a sign of or a risk factor for breast cancer. However, it's always best to see your doctor if you aren't sure what's causing your symptoms.

Mammary duct ectasia occurs most often in women in their 40s and 50s and affects as many as one in four women during or after menopause. It often causes no symptoms, but some women may have nipple discharge and breast tenderness.

Mammary duct ectasia usually improves without treatment. However, if symptoms persist despite self-care measures, you may need surgery to remove the affected milk duct.

Signs and symptoms

Mammary duct ectasia is one of the most common causes of abnormal nipple discharge. Although it often doesn't cause signs and symptoms, some women may experience:

  • A dirty white, greenish or black nipple discharge
  • Tenderness in the nipple or surrounding breast tissue
  • Redness
  • A lump or thickening
  • An inverted nipple

A bacterial infection such as mastitis also may develop in the affected milk duct and cause inflammation and fever. Signs and symptoms of mammary duct ectasia usually improve on their own.


Mammary duct ectasia occurs when a milk duct beneath the nipple becomes dilated and inflamed. Possible causes include:

  • Hormonal changes. Changes in your hormone levels may cause mammary duct ectasia. Hormonal changes are normal and often cause different kinds of breast changes, especially as you age.
  • Smoking. Studies show that nicotine may have a toxic effect on your milk ducts, causing them to become dilated and inflamed.
  • Inverted nipple. Repeat occurrences of inverted nipple can lead to mammary duct ectasia. A newly inverted nipple also may obstruct milk ducts, causing inflammation and infection. A nipple that's newly inverted also could be a sign of a more serious underlying condition, such as cancer.
  • Lack of vitamin A. A lack of vitamin A may cause abnormal changes in your breasts, such as mammary duct ectasia.

Risk factors

Factors that may increase your risk of mammary duct ectasia include:

  • Smoking. Women who smoke have an increased risk of mammary duct ectasia. The use of nicotine has been shown to cause abnormal changes in the milk ducts of the breast. The longer you've smoked, the higher your risk of mammary duct ectasia.
  • Number of pregnancies. The more pregnancies you've had, the higher your risk of mammary duct ectasia.
  • Infection. If you have a history of breast infection (mastitis), your risk of mammary duct ectasia may be increased.

Mammary duct ectasia does not affect your risk of breast cancer.

When to seek medical advice

Although mammary duct ectasia is not a sign of breast cancer, it's important for your doctor to promptly evaluate any changes in your breasts. If you have symptoms of mammary duct ectasia, make an appointment with your doctor for an evaluation. Your doctor will likely ask you some questions and perform a physical exam.

Screening and diagnosis

Mammary duct ectasia usually causes no symptoms. It may be found inadvertently on a mammogram or during a breast biopsy done for some other reason.

If you have symptoms of mammary duct ectasia, be prepared to answer these types of questions from your doctor:

  • Do you have symptoms in one or both breasts?
  • Do you have nipple or breast tenderness or redness?
  • Do you have a lump or thickening in your breast?
  • Do you have any other symptoms, such as a fever?

If you have nipple discharge:

  • What color is it?
  • How much is there?
  • Does it appear to come from one opening in your nipple or multiple openings?
  • Is it spontaneous, or does it happen only when you squeeze your nipple or breast?

Be sure to mention any other observations you think may be relevant. For instance, your doctor might want to know your medical history and how long you've had symptoms.

Based on the information you provide and the results of a physical exam, you might need to have additional tests, which may include:

  • Ultrasound. An ultrasound uses sound waves to make images of breast tissue. It allows your doctor to evaluate the milk ducts beneath your nipple.
  • X-Ray. An X-ray of your breast can help your doctor find the cause of nipple discharge.
  • Examination of nipple discharge. For this test, your doctor collects a sample of nipple fluid and sends it to a lab for analysis.


Complications of mammary duct ectasia are usually minor and often more bothersome than serious. These may include:

  • Nipple discharge. Nipple discharge caused by mammary duct ectasia can be frustrating. Fluid leaking from your nipples can cause embarrassing wetness and staining on your clothes.
  • Breast discomfort. Mammary duct ectasia can cause the tissue around your nipples to be red, swollen and tender.
  • Infection. A bacterial infection such as mastitis may develop in the affected milk duct, sometimes causing you to feel ill and have a fever.
  • Concern about breast cancer. You may worry about any changes in your breasts being a sign of breast cancer. Although mammary duct ectasia can sometimes cause scar tissue to form around the affected milk duct that feels like a hard lump, it's rarely linked to breast cancer.


Mammary duct ectasia often improves without treatment. If your symptoms are bothersome, however, treatment options may include:

  • Antibiotics. Your doctor may prescribe a 10- to 14-day course of antibiotics to treat any infection caused by mammary duct ectasia. Even if your symptoms greatly improve or disappear altogether, it's important to take the entire course of medication. While waiting for the antibiotics to take effect, take a mild pain reliever, such as acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin, others) as needed for breast discomfort.
  • Surgery. If antibiotics and self-care methods don't work, the affected milk duct may be surgically removed. This procedure is done through a tiny incision at the edge of the colored tissue around your nipple (areola). However, surgery rarely is needed for mammary duct ectasia.


Certain self-care remedies can help to reduce discomfort and alleviate signs and symptoms associated with mammary duct ectasia. Take these steps:

  • Apply warm compresses. A warm compress applied to your nipple area can reduce the pain and swelling often caused by mammary duct ectasia.
  • Wear a bra pad. If you have nipple discharge, wear a bra or nursing pad to keep the fluid from leaking through your clothing. These pads are available at local pharmacies and retail stores.
  • Wear a support bra. Wear a bra with good support to keep your breasts more secure and help reduce breast discomfort. Also, a support bra can help keep bra pads in place if you have nipple discharge.
  • Sleep on the opposite side. Try not to sleep on the side of your affected breast. This helps to prevent further discomfort and to keep any swelling down.

June 20, 2006

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