Benign Breast Conditions

What are benign breast conditions?

Benign breast conditions (also called benign breast diseases) are noncancerous disorders of the breast. They can occur in both women and men.

There are many types of benign breast conditions. Your health care provider may use the term fibrocystic change to describe a range of benign breast conditions.

This section discusses benign breast conditions in women.

Learn about benign breast conditions in men.

When is treatment or follow-up needed?

Some benign breast conditions cause discomfort or pain and need treatment. Some may need to be removed. Others don’t need treatment.

Many benign breast conditions mimic the signs and symptoms of breast cancer. These conditions will need follow-up tests and sometimes a biopsy for diagnosis.

If you need a biopsy, try not to panic or worry. In the U.S., most biopsy results don’t show cancer [20]. Still, a biopsy is needed to know whether or not something is cancer.

Are benign breast conditions linked to an increased risk of breast cancer?

Benign breast conditions are not breast cancer. However, some types (especially those with abnormal-looking cells, such as hyperplasia) are linked to an increased risk of breast cancer.

For example, women who have usual hyperplasia and those who have atypical hyperplasia have an increased risk of breast cancer [38-40,170]. Women with atypical hyperplasia have more of an increased risk than those with usual hyperplasia [38-40,170].

Learn more about hyperplasia and breast cancer risk.

What increases the risk of benign breast conditions?

A few factors are linked to an increased risk of benign breast conditions, including [21-23]:

Menopausal hormone therapy (postmenopausal hormone use)
A family history of breast cancer or benign breast conditions

Lifestyle factors during childhood and the teen years

Some lifestyle factors during childhood and the teen years may be linked to the risk of benign breast conditions in adulthood.

Some factors may be linked to an increased risk. For example, women who drink alcohol during the teen years may have an increased risk of benign breast conditions [24-26].

Other factors may be linked to a decreased risk. For example, women who eat nuts (including peanut butter), beans and foods that contain carotenoids (such as melons, carrots and sweet potatoes) during the teen years may have a decreased risk of benign breast conditions [27-29].

Also, girls who are heavy at age 10 may have a lower risk of benign breast conditions in young adulthood than girls who are lean at age 10 [28,30]. (Similarly, women who were heavy as children and teens may have a lower risk of breast cancer than women who were lean in their youth [31-36].)

However, being heavy during childhood and the teen years is not advised as it’s linked to an increased risk of heart disease and many other health conditions in adulthood [37].

These topics are under study.

Learn about lifestyle factors in childhood and the teen years that be linked to breast cancer risk.

Types of benign breast conditions

Benign breast conditions differ from each other in how the cells and their growth patterns look under a microscope. For example, hyperplasia looks different from a fibroadenoma.

If you are told you have a benign breast condition (or a fibrocystic change), ask your health care provider which type you have, if it needs treatment and if it increases your risk of breast cancer.

Some benign breast conditions are described below. (There are many types of benign breast conditions. This is not an exhaustive list.)

Hyperplasia describes an overgrowth (proliferation) of cells. It most often occurs on the inside of the lobules or milk ducts in the breast.

There are 2 main types of hyperplasia—usual and atypical.

Hyperplasia and breast cancer risk

Women who have usual hyperplasia and those who have atypical hyperplasia have an increased risk of breast cancer [38-40,170]. Women with atypical hyperplasia have more of an increased risk than those with usual hyperplasia [38-40,170].

Learn more about hyperplasia and breast cancer risk.

For a summary of research studies on hyperplasia and breast cancer, visit the Breast Cancer Research Studies section.

Breast cancer screening for women with atypical hyperplasia

For women with atypical hyperplasia who also have a greater than 20 percent lifetime risk of invasive breast cancer, there are special breast cancer screening recommendations. (Estimate your lifetime risk of breast cancer or learn more about breast cancer risk.)

The National Comprehensive Cancer Network (NCCN) recommends women with atypical hyperplasia who have a greater than 20 percent lifetime risk of invasive breast cancer [171]:

Have a mammogram every year, starting at age 30
Have a clinical breast exam every 6-12 months
Talk with their health care provider about screening with breast MR I, starting at age 25

This care helps ensure if breast cancer develops, it’s caught early when the chances of survival are highest.

Women with atypical hyperplasia who have a less than a 20 percent lifetime risk of invasive breast cancer and women with usual hyperplasia are recommended to get the same breast cancer screening as women at average risk.

Learn more about breast cancer screening for women at higher risk.

Risk-lowering drugs for women with atypical hyperplasia

The NCCN strongly recommends women with atypical hyperplasia take a risk-lowering drug (such as tamoxifen) to lower their risk of breast cancer [172].

Taking one of these drugs can lower the risk of breast cancer in women with atypical hyperplasia by about 86 percent [172].

There are no special breast cancer risk-lowering recommendations for women with usual hyperplasia. They are recommended to get the same breast cancer screening as women at average risk.

Learn more about risk-lowering drugs.

For a summary of research studies on the use of risk-lowering drugs to reduce breast cancer risk, visit the Breast Cancer Research Studies section.

Cysts are fluid-filled sacs that are almost always benign.

Cysts are more common in premenopausal women ages 35-50 [173]. After menopause, cysts occur less often [173].

Cysts and breast cancer risk

Most cysts are not linked to an increased risk of breast cancer [173].

Diagnosis of cysts

Most cysts are too small to feel. Some, however, are large and may feel like lumps in the breast and may cause breast pain [173].

Cysts are diagnosed with breast ultrasound and/or a fine needle aspiration (fine needle biopsy) [173].

Treatment for cysts

Often, cysts don’t need treatment.

If they’re painful or can be felt (and might interfere with a clinical breast exam), they can be drained (aspirated).

Risk factors for cysts

We don’t know what causes cysts to develop. Few data support a link between diet or other lifestyle factors and cysts [44].

Learn more about the early detection and diagnosis of cysts.

Fibroadenomas are solid benign tumors. They are the most common benign tumor in the breast [174].

They occur most often in women ages 15-35 [174].

Often, a fibroadenoma doesn’t need treatment. However, if it’s large or causes discomfort, it may be removed [174]. It may also be removed if it’s bothering you [174].

Fibroadenomas and breast cancer risk

Most fibroadenomas are not linked to an increased risk of breast cancer [174].

Learn more about the early detection and diagnosis of fibroadenomas.

Intraductal papillomas are small growths that occur in the milk ducts of the breasts.

They are usually close to the nipple and can cause nipple discharge and pain. You may feel a lump.

They occur most often in women ages 35-55 [46].

Intraductal papillomas are removed with surgery, but don’t need any other treatment [174-175].

Intraductal papillomas and breast cancer risk

Women who have one intraductal papilloma don’t have an increased risk of breast cancer unless the intraductal papilloma has abnormal cells or there’s ductal carcinoma in situ (DCIS) in the nearby tissue [46-47,174].

Women who have 5 or more intraductal papillomas at the time of diagnosis may have an increased risk of breast cancer [174].

Sclerosing adenosis is made up of small breast lumps in a lobule of the breast. It may be painful, and you may feel a lump.

Sclerosing adenosis may be seen on a mammogram. Because it has a distorted shape, it may be mistaken for breast cancer. A biopsy may be needed to rule out breast cancer.

Sclerosing adenosis doesn’t need treatment [174].

Sclerosing adenosis may be found with atypical hyperplasia, lobular carcinoma in situ (LCIS) or ductal carcinoma in situ (DCIS) [46].

Sclerosing adenosis and breast cancer risk

Some studies have found sclerosing adenosis is linked to a slightly increased risk of breast cancer, while others have found no link between the two [48-49].

Radial scars (also called complex sclerosing lesions) have a core of connective tissue fibers. Milk ducts and lobules grow out from this core.

Although radial scars can look like breast cancer on a mammogram, they are not cancer.

Radial scars are removed with surgery, but don’t need any other treatment [174].

Most often, radial scars are a secondary finding when a biopsy is done for other reasons [174].

Radial scars and breast cancer risk

Some studies have found radial scars are linked to an increased risk of breast cancer, while others have found no link between the two [50-52,176].

Radial scars are typically found alongside other breast conditions, which may explain these mixed findings [50].

Phyllodes tumors

Phyllodes tumors are fast-growing breast lumps that begin in the connective tissue of the breast [53]. They are usually painless [177].

The word “phyllodes” means leaf-like. This describes how phyllodes tumor cells look under a microscope.

Some phyllodes tumors develop slowly over time and some are fast-growing. Phyllodes tumors can be benign (not cancer), malignant (cancer) or borderline (of uncertain behavior).

With most phyllodes tumors, you can feel a breast lump. Sometimes, they appear as an abnormal finding on a mammogram.

They are most common in women in their 40s [53,177].

Diagnosis and treatment of phyllodes tumors

Most phyllodes tumors are benign, but about 25 percent are cancerous [53,177].

A phyllodes tumor may be suspected on core needle biopsy findings. However, in most cases, the diagnosis is not certain until after surgery to remove the tumor [177]. A pathologist studies the tissue under a microscope to make the diagnosis.

For benign phyllodes tumors, surgery to remove the tumor is the only treatment needed [177]. Regular mammograms and other imaging tests may be needed as benign phyllodes tumors can come back (recur) [53].

If a benign phyllodes tumor comes back, another biopsy or surgery will be needed to confirm the diagnosis.

Malignant phyllodes tumors are rare invasive breast cancers. They account for fewer than one percent of all invasive breast cancers [177].

Learn about malignant phyllodes tumors.

Benign phyllodes tumors and breast cancer risk

Benign phyllodes tumors are not linked to an increased risk of breast cancer [53].

Fat necrosis is a breast lump usually caused by injury, surgery to the breast (including breast reconstruction) or radiation therapy to the breast [174,178]. In some cases, there’s no history of an injury.

The lump is made of damaged or dead fatty tissue cells in the breast and can change into scar tissue over time.

The skin around the lump may look red, bruised or thicker than the other skin of the breast [178]. The lump usually isn’t painful [178].

Fat necrosis is more common in women with very large breasts than in other women [178].

Fat necrosis may mimic signs of breast cancer on a mammogram or clinical breast exam. A needle biopsy may be needed to confirm the diagnosis.

In most cases, fat necrosis doesn’t need to be surgically removed or treated [174,178]. Sometimes, it will go away on its own [178].

Fat necrosis and breast cancer risk

Fat necrosis is not linked to an increased risk of breast cancer [174,178].

Mastitis is swelling (inflammation) in the breast that may be painful. The breast may look red and feel warm. It can also cause flu-like symptoms or a fever. It’s usually caused by an infection.

Mastitis usually occurs in women who are breastfeeding, when a milk duct becomes clogged [56].