Atypical Hyperplasia

Author: OncoLink Team
Content Contributor: Allyson Distel, MPH
Last Reviewed: February 26, 2024

What is atypical hyperplasia?

“Hyperplasia” is when there are more cells than there should be. It is an "overgrowth" of cells. “Atypia” means that the cells look different than normal cells, but not quite like cancer cells. Put those terms together and “Atypical Hyperplasia” is an overgrowth of cells that look abnormal.

Atypical hyperplasia can be found during a breast biopsy. It is NOT cancer but it increases the risk of breast cancer. Women who have had a biopsy that shows atypical hyperplasia have about a four times higher risk of breast cancer in the future. Often, atypical hyperplasia has no symptoms, but changes in the breast may be seen on a mammogram.

If you have atypical hyperplasia, you should:

  • Have a screening every year by a healthcare provider that includes a mammogram and breast exam.
  • Know your breast tissue which may mean doing a self-exam.
  • Tell your healthcare provider if you have any changes.

If you have atypical hyperplasia, you may be able to take a medication (tamoxifen or raloxifene) to lessen the chance of breast cancer. This is called chemoprevention. You should discuss these options with your healthcare providers.

If you have atypical hyperplasia, you should:

Learn more about prevention with medications (called chemoprevention) on OncoLink.

Learn more about atypical hyperplasia from the Dr. Susan Love Foundation.


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