Atypical Lobular Hyperplasia of the Breast

In This Article

Atypical lobular hyperplasia (ALH) is not breast cancer, but is considered a precancerous condition. Atypical lobular hyperplasia occurs in the epithelial cells lining the milk lobes, producing more cells than would normally grow there. Some of these cells are irregular in shape and size, and thus they are called atypical. Usually, a lobe is lined with one even layer of uniformly shaped cells, but in ALH there may be several layers of cells. This is similar to atypical ductal hyperplasia, which causes more cells to develop in the lining of the breast ducts (milk producing glands).

A diagnosis of atypical lobular hyperplasia means your risk for developing breast cancer is higher than the average risk. You will need to be vigilant about your breast health, and may need a breast MRI along with your annual screening mammogram. Women between the ages of 45 to 55 with atypical hyperplasia have the highest future risk of developing breast cancer.

ALH is also known as lobular hyperplasia with atypica, mammary atypical lobular hyperplasia, epithelial atypical hyperplasia, or proliferative breast disease.

Signs and Symptoms

Atypical lobular hyperplasia doesn't cause any notable symptoms. It is usually found on a routine screening mammogram. In a few cases, atypical lobular hyperplasia may cause breast pain. When hyperplasia shows up on a mammogram or ultrasound, a tissue sample can be taken to get a clear diagnosis.

If you notice any signs or symptoms on a breast self-exam, you should bring these to the attention of your doctor.  These may include: 

  • Breast swelling or chest pain
  • Pain in the armpit or traveling from the breast to the armpit
  • A breast lump or mass that feels hard and/or is movable
  • Nipple discharge that is white, yellow or bloody
  • A misshapen breast or uneven breasts


An exact cause of ALH is unknown. Doctors believe it is a natural part of breast changes for some women as they age. It often affects women over age 35, but it can affect women regardless of age. It may also affect men but is very rare.

Risk factors of ALH are similar to those for other benign breast conditions, including:

  • Postmenopausal hormone use
  • Family history of breast cancer and benign breast conditions
  • Certain lifestyle factors, including over-consumption of alcohol, smoking, being overweight and not having an unhealthy diet


Imaging and a tissue sample biopsy will be needed to make a diagnosis of ALH.

  • Mammogram: ALH appears as a cluster of microcalcifications on a mammogram
  • Ultrasound: A breast ultrasound uses sound waves to reveal groups of microcalcifications
  • Breast Biopsy: A breast biopsy is the most definitive method for diagnosis of ALH. It will allow the pathologist to determine the location and nature of cells. The pattern of growth is abnormal and may contains cells that are characteristic of Lobular Carcinoma in Situ (LCIS), which is not cancer, but rather an overgrowth of cells in the lobules.

Some people may choose an excisional biopsy to remove the suspicious tissue. If you have a family history of breast or ovarian cancer, or if you have a BRCA gene mutation, you'll need to balance that in with your treatment decisions.


Women with ALH will be advised to stop taking oral contraceptives and avoid hormone replacement therapy. Both the birth control pill and hormone replacement therapy can increase your risk for developing breast cancer.

Surgery can remove abnormal cells and make sure no in-situ and invasive cancer cells are also present in the area. Doctors will also recommend intensive screenings to get a ahead of a potential breast cancer diagnosis and medication to reduce breast cancer risk.

It is difficult to predict which cases of atypical lobular hyperplasia will remain benign and which may become malignant, and doctors can disagree on what your options are after diagnosis. Most people will need extra screening mammograms and/or breast MRIs to keep track of any changes and address any issues as they arise.

Breast Cancer Risk

A person with atypical lobular hyperplasia has an up to 2 percent increased lifetime risk for developing breast cancer.  People who have this risk and risk factors for breast cancer should be informed about all risks, work with their doctors on appropriate surveillance methods, and practice prevention strategies. Prevention methods have been found to reduce breast cancer risk by up to 70 percent for women with high risk breast conditions.

A Word From Verywell

If you are diagnosed with atypical lobular hyperplasia, do what you can do to reduce your risk of developing a breast cancer. See a nutritionist and develop a healthy eating plan. Watch your weight, keep alcohol consumption to a minimum and don't smoke. Get regular checkups and take the time to become educated about risks associated with breast cancer and benign breast conditions.

Was this page helpful?

Article Sources