Atypical Lobular Hyperplasia of the Breast

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Atypical lobular hyperplasia (ALH) is not breast cancer, but is considered a precancerous condition. Your doctor may also refer to this condition as "proliferative breast disease." 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, thus they are called atypical. Usually, a lobe is lined with one even layer of uniformly shaped cells, but in lobular hyperplasia there may be several layers of cells. This is similar to atypical ductal hyperplasia.

A diagnosis of atypical lobular hyperplasia means that your lifetime risk for developing breast cancer is 4 to 5 times the average risk. Atypical lobular cells are abnormal and have the potential for developing into lobular carcinoma in situ (LCIS), a type of noninvasive breast cancer. You will need to be vigilant about your breast health, and may possibly have 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 atypia, 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.


You may not need all of these diagnostic tests, but some imaging and a tissue sample will be needed to get a clear diagnosis.

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. Many people just need extra screening mammograms and/or breast MRIs to keep track of any changes.

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. With a family history of breast cancer and/or gene mutations, it's usually best to consult a genetic counselor. Gene testing is still in its infancy, and there is much left to learn about possible genetic predispositions to breast cancer. A good counselor can help you tremendously by looking at your full cancer family history (for example, a history of pancreatic cancer raises the chance that you have a BRCA2 gene mutation) and may be help guide you in any decisions you make.


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

Making appropriate lifestyle and dietary changes that may decrease their risk of breast cancer (for example, eating a diet rich in fruits and vegetables, fish, and olive oil and engaging in regular exercise at least 5 days a week) is also important.

They should be encouraged to see a specialist that would calculate their risk of developing invasive breast cancer using the Gail model. The benefits and risks should be discussed accordingly and, primary prevention using tamoxifen or raloxifene, may be recommended for some women.

If ALH is found by a core needle biopsy a surgical excision should be performed to avoid underestimation of the diagnosis.


About one out of every 25 women will be diagnosed with atypical hyperplasia, either in their milk ducts or breast lobes. About 20 percent of these women may develop lobular carcinoma in situ or invasive lobular carcinoma within 15 years after their diagnosis. 

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. Take the time to become educated about risks. For example, many women are unaware that using the birth control pill raises breast cancer risk. The increase is not that high, but for someone who already has an increased risk, it is certainly significant.

Take the time to learn about the controversy with mammograms and overdiagnosis. We don't have a perfect breast cancer screening test at this time. Mammograms can both miss cancers, and result in false alarms. Breast MRIs are becoming almost standard of care for those at an increased risk of the disease due to better detection.

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