Heterogeneously Dense Breasts: What Your Mammogram Means

Have you read your mammogram report and seen the words “heterogeneously dense”? It sounds worrying, but it does not mean something is wrong. It means your breasts contain many areas of glandular and fibrous tissue, along with some fatty tissue.

About 40% of women receive this result. Dense tissue appears white on a mammogram, and some abnormal areas also appear white. That overlap can make changes harder to see. This article explains what heterogeneously dense means, what causes it, how it affects screening, and when you should ask about extra imaging.

What Heterogeneously Dense Means

Heterogeneously dense is a descriptive term used for breast density. This term does not describe a disease, but instead is a classification. The BI-RADS (Breast Imaging Reporting and Data System) classification system is utilized by radiologists to measure how much dense tissue was observed during an X-ray examination of the breasts.

• Heterogeneously Dense: This is a type of breast tissue that contains both glandular and fibrous tissue along with some fat. Approximately forty percent of women have this type of breast tissue.
• The area of the breast that contains fat and areas where there are some denser areas (called scattered fibroglandular density) is considered BI-RADS Category B.
• Extremely Dense – All of your breast tissue is primarily made up of dense glandular and fibrous tissue. This falls under BI-RADS Category D.
• Breast density: A combination of fat, glands, and fibers that can be seen on a mammogram. This density cannot be felt with a breast self-exam.
• Fibroglandular tissue: Glandular tissue that produces milk and the fibrous support for that tissue. This type of tissue will appear white on a mammogram.

Why Breast Tissue Looks Dense

Breast density is very common among women. Almost half of all women ages 40 and older who have a mammogram have dense breast tissue.

Genes And Body Type

A woman’s breast density can run in families. You are more likely to have dense breasts if your mother or sister has dense breasts.

As well, a lower BMI is associated with an increased density of the breasts. While this is true, it does not imply that all women who are considered thin will have dense breasts. Body composition is simply one variable out of many that can affect the density of the breasts.

Age And Hormones

As women grow older, their breast tissue tends to lose density. Following menopause, women can expect a decrease in the amount of glandular tissue in their breasts, along with an increase in the amount of fatty tissue.

Menopausal hormone treatment increases the risk of breast density. Childbearing reduces the risk of breast density for a period of time.

Why You Cannot Feel It

There is no way for you to know if your breasts are “dense” just by touching them. Even if you find a lump, feel tenderness, or have a firm feeling in one of your breasts, that does not mean you have dense tissue.

Only a radiologist who reviews a mammogram will be able to determine the size of the abnormality. This is why the result of your test, and not your own examination of yourself, will provide you with this information.

How Density Affects Mammograms

Dense tissue and fatty tissue look different on an X-ray. Fat appears dark. Glandular and fibrous tissue appear white.

Why Changes Are Harder To See

Some abnormal areas also look white on a mammogram. On the image, white changes can hide inside white dense tissue.

This lowers mammogram sensitivity in dense breasts. In plain words, a mammogram has a higher chance of missing a change when tissue is dense.

Why You May Get Called Back

Dense tissue can create shadows or overlapping areas. A radiologist may need more pictures to tell normal tissue from a possible change.

A callback does not mean something serious. It means the radiologist wants clearer images before making a decision.

What It Means For Your Risk

Because of their increased tissue density, breasts contain more fibrous and glandular tissue and less fat. This results in an increased risk for breast disease as compared to less dense or mostly fatty breasts.

•  Increased risk: Because of their increased density as compared to less dense breasts, these breasts carry an increased risk. However, increased density of the breasts is a risk factor and does not mean that breast disease is inevitable.
• Masking of Changes: Increased breast density can mask changes on a mammogram. The masking of changes, however, does not mean that a breast disease is present.
• Not a problem by itself: Having dense breasts is a normal condition and is not a cause for immediate concern. Many women with increased breast density do not develop breast disease.
• Other factors: Family history, changes in genes, prior radiation therapy, and certain biopsy results can also increase a person’s risk of developing breast disease.
• Screening: Mammography remains the primary test to screen for breast disease, even for women with dense breasts.

Extra Screening Options

Your report may say your breasts are “heterogeneously dense.” Risk is interpreted on an individual basis and not automatically assigned. Therefore, ask your clinician for more information about your personal risk. Additional imaging for breast density is not automatically ordered.

3D Mammograms

A 3D mammogram, also known as breast tomosynthesis, is a technique to reduce tissue superposition by taking multiple thin images of the breast. Like traditional mammography, 3D mammograms are considered a type of ionizing radiation exposure. However, it is believed that 3D mammograms may improve breast cancer detection.

Ask your clinician to see if the imaging center utilizes this technology. Also, determine if your insurance will cover the exam.

Breast Ultrasound

Breast ultrasound utilizes sound waves and is another alternative for women with dense breasts. Like a mammogram, a breast ultrasound carries some risk for producing false positive results, which may require further evaluation.  Before getting a breast ultrasound, talk to your clinician about potential benefits and risks.

Breast MRI

Magnetic Resonance Imaging (MRI) uses a magnetic field and radio waves to produce cross-sectional images of the body. It may be more effective than a traditional mammogram for women at high lifetime risk for breast cancer. The American College of Radiology recommends a breast MRI for women with a lifetime risk of developing breast cancer at or above 20%. Breast density alone does not meet this recommendation.

Can You Reduce Dense Breast Tissue?

You do not have a choice over your own breast density, nor can you get rid of it on your own. Most breast density is genetic; however, there are many factors that influence the amount of dense tissue in a woman’s breasts, such as her age, hormones, and life events.

Many websites state that you can decrease dense breast tissue by using exercise, specialized diets, vitamins, supplements, and detoxing. Currently, there is no scientific proof that any of these products will decrease your breast density. Do not miss your regular breast cancer screening due to an unproven product or claim.

You can still support your overall health:

• Keep regular mammogram appointments.
• Tell your clinician about any new lump or breast change.
• Share your family history of breast and ovarian illness.
• Ask whether your personal risk calls for extra imaging.
• Avoid smoking and limit alcohol, which support better long-term health.

World Dense Breast Day provides an excellent opportunity to review the results of your mammogram. If the report states that your breasts are “heterogeneously dense,” make sure to keep a copy of that report and use it as a basis for discussion with your doctor during your next visit.

How Eaessi Can Help

EAESSI helps eligible uninsured women receive a free mammogram. It provides access to breast screenings for uninsured women in Northern Virginia. To qualify, women must be between the ages of 39 and 64 and fall within the program’s income requirements.

You don’t need a physician’s referral to fill out the application. Fill out the application form with your age, ZIP code, income range, and insurance status. EAESSI will determine if you qualify for the program, help schedule an appointment at one of our partner locations, and coordinate the payment of the screening.

The process is completely confidential, non-judgmental,l and at no expense for eligible women. If price has prevented you from obtaining a screening, please contact EAESSI via their website for assistance.

Conclusion

“Heterogeneously dense” refers to the fact that when you have a mammogram taken, there will be numerous regions where you have both dense glandular tissue and dense fibrous tissue. This type of density is typical; it is not a condition, nor does it indicate that something is wrong within your body.

That’s because having dense tissue means it may be more difficult to spot changes on your mammogram and therefore increases your risk of breast health problems slightly. It is important to read through your report; understand your family’s medical history; and discuss with your physician if you should consider 3D mammography, ultrasound, or MRI as options for screening. Additionally, if you are without insurance and qualify for services provided by EAESSI, they can provide you with free screening.

Frequently Asked Questions