An Overview Atypical Ductal Hyperplasia of the Breast

Symptoms, Diagnosis, Causes, and Treatment

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Atypical ductal hyperplasia (ADH) is not breast cancer but is considered a precancerous condition. Atypical ductal hyperplasia indicates there are more cells lining the duct than would normally be there, and some of these cells are not typical as they are irregular in shape and size. Usually, a milk duct is lined with one even layer of uniformly shaped cells, but in ductal hyperplasia, there may be many layers of cells.

ADH is similar to atypical lobular hyperplasia. However, atypical lobular hyperplasia involves epithelial cells lining the lobules of the breast rather than the milk ducts.

Atypical ductal hyperplasia may also be called mammary atypical ductal hyperplasia, epithelial atypical hyperplasia, intraductal hyperplasia with atypia, or proliferative breast cancer.


Atypical ductal hyperplasia usually doesn't cause any notable symptoms. It is usually found when a biopsy is done to evaluate a benign breast lump or area of thickening in the breast.

You should make an appointment with your doctor if you have symptoms that may worry you, especially those that may be a sign of breast cancer including:

A lump: A breast lump is the most common symptom of breast cancer. You should perform monthly breast self-exam about two weeks after the start of your period.

Breast pain: Breast cancer tends to be painless especially early on. However, as a tumor grows, it may stretch skin and breast tissue, causing pain, swelling or discomfort. While rare, atypical ductal hyperplasia may cause breast pain.

Changes to breast tissue:  A tumor can affect the size or shape of your breast, even making breasts look uneven.

Changes to the nipple: The nipple may appear to be going inward into the breast or the skin of the nipple may be flaky or crusty.

Skin changes: Skin dimpling (having the texture of an orange peel) or changes in skin color may warrant medical attention

Itching: Redness and itchiness may be similar to mastitis, a breast infection

Nipple discharge: Discharge may appear yellow, milky or even be bloody

Causes and Risk Factors

A specific cause for ADH is unknown. The condition forms when breast cells become abnormal in number, size, shape, appearance and growth pattern. 

The condition is thought to be involved in a transition of cells that eventually will become cancer. The overproduction of these normal cells will eventually begin to take abnormal forms. If the condition is not properly managed, it will continue to develop and eventually become breast cancer. It may also affect nearby tissues. 

The risk factors for ADH are similar to those for all types of breast cancer, including:

  • Getting older: The risk for breast cancer and benign breast conditions increases with age and most breast cancers are diagnosed after age 50.
  • Genetic mutations: Inherited mutation to certain genes, such as BRCA1 and BRCA2.
  • Reproductive history: This includes early menstruation before age 12 and starting menopause after age 55. Having a pregnancy after age 30, not breastfeeding and never having a full-term pregnancy are also risk factors.
  • Have dense breast tissue: Dense breasts have more connective tissue than fatty tissue, which allows cancerous-type cells room to grow.
  • Family history: A woman’s risk is higher if she has a first-degree relative (mother, sister, or daughter) who has had breast cancer, or multiple family members (on both parents’ sides) who have had breast cancer. Having a first-degree male relative who has had breast cancer is also a risk factor for women.
  • Previous radiation treatments:  A woman who has had previous radiation therapy to her chest or breasts before age 30 has a higher risk for getting breast cancer later one.
  • Not being active and/or being overweight after menopause: Women who are not physically active and women who are overnight after menopause have an increased risk.
  • Taking hormones: Birth control pills and hormone replacement therapy have been shown to raise risk.
  • Alcohol consumption: Over-consumption of alcohol may increase risk.
  • Smoking and chemical exposure: Smoking and exposure to other chemicals that cause cancer also increase risk for breast cancer and benign breast conditions.  


Tests that may suggest that ADH is present or confirm the diagnosis include:

  • Mammography: ADH often appears as a pattern of calcifications on a mammogram.
  • Ultrasound: An ultrasound uses sound waves to assess the appearance of a lump or thickening in the breast and may also reveal calcifications.
  • Ductal Lavage: In a ductal lavage, breast cells are withdrawn through the nipple through a suction technique. Under the microscope, some of these cells may appear atypical.
  • Breast Biopsy: The definitive test for diagnosing atypical ductal hyperplasia is a breast biopsy. Unlike a ductal lavage which may find cells that are atypical, a breast biopsy also allows your physician to determine the location of those cells. A tissue sample may be obtained by either a core needle biopsy (needle localization biopsy during an ultrasound) or by an open surgical breast biopsy.

Follow-Up After Diagnosis

Since it is hard to predict whether atypical ductal hyperplasia will continue to be benign (non-cancerous) and when it may turn malignant (cancerous), you have some options after diagnosis. Many people will opt for extra screening mammograms alone, to keep track of any changes.

One 2014 report in the Journal of of Breast Cancer reported on a Korean study that found that almost half of women diagnosed with ADH eventually develop breast cancer.

The researchers suggested the women most likely to go on to develop breast cancer were less than 50 years old, had microcalcifications on their mammogram, a mass smaller than 15 mm (1.5 cm or slightly smaller than an inch in diameter), and a lump that could be found by touch (a palpable lump).

With ADH, the pattern of cell growth is abnormal and may have some features of ductal carcinoma in-situ, which is pre-cancer in the ducts of the breast. When it is found on biopsy, more tissue will be removed to make sure there is nothing else more serious in breast tissue. If nothing is found, no treatment is needed. 


Once you've been diagnosed with ADH, you'll be asked to make a choice on what to do next. Your options at that point include:

Watching and waiting: Often physicians will advise women to take a "wait and see" approach to ADH. The rationale behind this approach is that at least half of women with ADH will not go on to develop breast cancer, and removal could bring unnecessary risk.

Medication: Your doctor may suggest medicines that prevent breast cancer, including estrogen receptor modulators (SERMs) that block estrogen from acting on certain cells. 

Surgical treatment: For those who are at a high risk of developing breast cancer, or feel very anxious and worried about the finding of ADH, surgical treatment is certainly an option. While surgery may be a better choice for those at risk—for example, those less than 50, with larger tumors or tumors that can be felt on exam, or with other risk factors—it is clearly an option even for those who do not have these risk factors.

Surgical options may include:

  • Ultrasound-Guided, Vacuum-Assisted Excision: Vacuum-assisted excision is a relatively noninvasive method of removing the atypical area of tissue. This is not an option for everyone.
  • Lumpectomy: Lumpectomy involves removing the tissue containing the area of abnormal cells plus a margin of surrounding tissue to help prevent recurrence.
  • Mastectomy: Some women have areas of ADH that are widely scattered throughout their breast (or both breasts.) When this occurs a woman may opt to have a mastectomy to remove all potentially abnormal breast tissue.

A Word From Verywell

The decision on whether to watch and wait with mammograms or have the area of your breast with atypical ductal hyperplasia removed is very personal.

Whether you decide to "watch and see" or have the area of concern in your breast removed, breast cancer remains far too common in women. Researchers have said that stressful times such as these—finding out you have atypical ductal hyperplasia—are a good opportunity to lower your risk factors for ill health in general. If you've been diagnosed with ADH, this could be a good time to improve your overall health with an anticancer diet, regular exercise, lower stress levels, and regular breast self-exams and screenings.

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