Atypical Ductal Hyperplasia of the Breast

Symptoms, Diagnosis, and Treatment

Patient waiting on examination table
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If you've been told that you have "atypical ductal hyperplasia" what does this mean? Does it raise the risk of developing breast cancer or could it already be breast cancer? What are the next steps, and how is it treated?


Atypical ductal hyperplasia (ADH) is not breast cancer but is considered a precancerous condition. Atypical ductal hyperplasia indicates that there are more cells lining the duct than would normally be there, and some of these cells are not typical or "normal”—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.

This is similar to atypical lobular hyperplasia, but atypical lobular hyperplasia involves epithelial cells that line 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.

The Risk of Breast Cancer

If you've been diagnosed with atypical ductal hyperplasia, your risk of developing breast cancer is four to five times the average lifetime risk. Atypical cells are abnormal and have greater potential for developing into noninvasive breast cancer, such as ductal carcinoma in situ (DCIS). 

It can be very frightening to hear that you have a condition which raises the risk of breast cancer. It may help to keep in mind that the changes in your breast are still precancerous changes, and even when these changes have progressed to carcinoma, the survival rate should be close to 100 percent. Ductal carcinoma in situ (or stage 0 breast cancer) has not yet spread beyond something called the "basement membrane" and for that reason is not yet considered invasive cancer. This is easier to say than to cope with and it's important to have a careful discussion with your doctor about the pros and cons of removing any areas of atypical hyperplasia in your breast.

Signs And Symptoms

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. Rarely, atypical ductal hyperplasia may cause breast pain. Hyperplasia may be suggested by findings on a mammogram or ultrasound, but a tissue sample is needed (biopsy) get a clear diagnosis.

Tests Used to Diagnose ADH

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 to 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 very hard to predict when 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. A study by Korean surgeons in 2008 found that a little less than half of all women diagnosed with ADH developed breast cancer. 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). Some people may choose a may choose a type of breast surgery to remove the suspicious tissue. 


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 waiting: Often physicians will advise women to take a "wait and see" approach to atypical ductal hyperplasia. 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.

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. Some people argue that even those without ADH who are at risk of breast cancer sometimes have preventive surgery. 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 atypical ductal hyperplasia 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.


About one out of every 25 women will be diagnosed with atypical hyperplasia—either in their milk ducts or breast lobes. About one in five of these women will develop invasive breast cancer within 15 years after their diagnosis. 

Bottom Line

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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