Table of ContentsView AllTable of ContentsBreast Tissue TypesBreast DensityRelevanceCausesRisk FactorsScreeningsHow Do I Know if I Have Dense Breasts?
Table of ContentsView All
View All
Table of Contents
Breast Tissue Types
Breast Density
Relevance
Causes
Risk Factors
Screenings
How Do I Know if I Have Dense Breasts?
“Fibroglandular density” is a term used to describe how much of the breast tissue is dense or fatty. People with dense breasts have more fibrous and glandular tissue and less fatty tissue. People with scattered fibroglandular density have more fatty tissue than fibrous and glandular tissue.
Dense breasts are common. About half of people who getmammogramshave high fibroglandular density. High fibroglandular density makes it more difficult for mammograms to catchbreast cancerand can raise the risk of developing breast cancer.
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Thebreastis made up of three different types of tissues, including:
What Is Fibroglandular Density?
Fibroglandular density refers to breasts that have more fibrous and glandular tissue and less fatty tissue. This is also calleddense breast tissue.
After a mammogram, breast tissue is rated based on its density or fibroglandular ratio. The standard system used to interpret the results is called theBreast Imaging Reporting and Data System (BI-RADS).The scale is as follows:
If someone falls into the areas of entirely fatty breasts (category A) or scattered dense tissue (category B), they have low fibroglandular density.
Those who have evenly dense tissue throughout or extremely dense tissue have high fibroglandular density (categories C and D).This means that fibroglandular densities are very common, with 50% of women in that category.
Why Is Fibroglandular Density Important?
There are two important reasons for people to know if they have high fibroglandular density. These include:
When it does develop, breast cancer usually occurs in glandular tissue. The more glandular tissue you have, the higher the risk.
The risk of breast cancer increases withbreast density. The risk is twice as high for people with extremely dense breast tissue (category D) compared to those with scattered density (category B).
What Causes Fibroglandular Density?
However, weight gain and some medications can also have an influence on breast density.
Risk Factors for Fibroglandular Densities
The amount of fibroglandular density someone has changes over time. Certain factors can put someone at a greater risk of having high fibroglandular densities, including:
Screenings for Fibroglandular Density
People with high fibroglandular densities will be screened differently for breast cancer than people with low fibroglandular densities. Therefore, it’s important to know which type of breast tissue someone has.
A healthcare provider may use one of the following tools to screen someone for fibroglandular density:
Mammography
Mammogramsare X-ray pictures of the breast.They are used as the first-line screening for breast cancer and can identify if someone has dense breast tissue. Mammogram reports are required to include breast density information.
When someone has been identified as having fibroglandular densities or dense breast tissue, a healthcare provider may recommend further screening tools.
Mammogram ScreeningsMost health insurance plans are required to cover screening mammograms every one to two years beginning at age 40.The U.S. Preventive Services Task Force (an organization made up of doctors and disease experts) recommends those who are 40 to 74 years old and at average risk for breast cancer get a mammogram every two years.Several medical organizations recommend mammograms starting at age 30 for women at higher-than-average risk for developing breast cancer.
Mammogram Screenings
Most health insurance plans are required to cover screening mammograms every one to two years beginning at age 40.The U.S. Preventive Services Task Force (an organization made up of doctors and disease experts) recommends those who are 40 to 74 years old and at average risk for breast cancer get a mammogram every two years.Several medical organizations recommend mammograms starting at age 30 for women at higher-than-average risk for developing breast cancer.
Most health insurance plans are required to cover screening mammograms every one to two years beginning at age 40.
The U.S. Preventive Services Task Force (an organization made up of doctors and disease experts) recommends those who are 40 to 74 years old and at average risk for breast cancer get a mammogram every two years.
Several medical organizations recommend mammograms starting at age 30 for women at higher-than-average risk for developing breast cancer.
Ultrasound
If you have dense breast tissue and are at an average risk for breast cancer, your healthcare provider may order abreast ultrasound.
Ultrasound uses sound waves to create an image of the breast. An ultrasound can identify abnormal breast tissue that a mammogram cannot detect.
MRI
AnMRIuses magnets and radio waves to produce a detailed image. It can detect breast cancer in people with high fibroglandular density that a mammogram may miss.
The downside to MRIs is that they are more likely to producefalse-positive results(detecting disease is present when it in fact is not). This can lead to additional unnecessary testing.
Biopsy
Abreast biopsyis a procedure in which a small piece of breast tissue is removed and tested for cancer cells. The procedure may be used to check a lump in the breast, to investigate problems seen on a mammogram, or to evaluatenipple problems.
These three types of breast biopsies can be performed:
As of September 10, 2024, the Food and Drug Administration (FDA) requires all mammogram reports that are sent to people include information about breast density, described as either “not dense” or “dense.”
Specifically, the report will read as follows if breast tissue is:
Not dense: “Breast tissue can be either dense or not dense. Dense tissue makes it harder to find breast cancer on a mammogram and also raises the risk of developing breast cancer. Your breast tissue is not dense. Talk to your healthcare provider about breast density, risks for breast cancer, and your individual situation.”
Dense:“Breast tissue can be either dense or not dense. Dense tissue makes it harder to find breast cancer on a mammogram and also raises the risk of developing breast cancer. Your breast tissue is dense. In some people with dense tissue, other imaging tests in addition to a mammogram may help find cancers. Talk to your healthcare provider about breast density, risks for breast cancer, and your individual situation.”
The mammography report sent to your healthcare provider must include a more detailed assessment of breast density using categories A through D.
Summary
Fibroglandular density describes how much of the breast tissue is dense or fatty. Mammograms can identify the density of the tissue.
Breast tissue that falls under category A or B is considered fatty. Tissue that classifies as category C or D is considered dense. Dense breasts can make it difficult to detect breast cancer on mammograms and can increase the risk of developing cancer.
If you have high fibroglandular density, you will need additional screenings to ensure the tissue is healthy and noncancerous. Having high fibroglandular density is normal but requires additional healthcare attention. Talk to your healthcare provider if you are concerned about dense breasts.
14 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Memorial Sloan Kettering Cancer Center.Anatomy of the breast.National Cancer Institute.Dense breasts: answers to commonly asked questions.Breastcancer.org.Dense breasts.American Cancer Society.Breast density and your mammogram report.Centers for Disease Control and Prevention.About dense breasts.Johns Hopkins Medicine.My doctor says I have dense breasts: what are dense breasts?Centers for Disease Control and Prevention.What is a mammogram?U.S. Food and Drug Administration.Important Information: Final Rule to Amend the Mammography Quality Standards Act (MQSA).Centers for Disease Control and Prevention.Screening for breast cancer.Breastcancer.org.When to get a mammogram.MD Anderson Cancer Center.Dense breast tissue: what it is, and what to do if you have it.Johns Hopkins Medicine.Breast magnetic resonance imaging (MRI).Johns Hopkins Medicine.Breast biopsy.American Cancer Society.Breast density and your mammogram report.
14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Memorial Sloan Kettering Cancer Center.Anatomy of the breast.National Cancer Institute.Dense breasts: answers to commonly asked questions.Breastcancer.org.Dense breasts.American Cancer Society.Breast density and your mammogram report.Centers for Disease Control and Prevention.About dense breasts.Johns Hopkins Medicine.My doctor says I have dense breasts: what are dense breasts?Centers for Disease Control and Prevention.What is a mammogram?U.S. Food and Drug Administration.Important Information: Final Rule to Amend the Mammography Quality Standards Act (MQSA).Centers for Disease Control and Prevention.Screening for breast cancer.Breastcancer.org.When to get a mammogram.MD Anderson Cancer Center.Dense breast tissue: what it is, and what to do if you have it.Johns Hopkins Medicine.Breast magnetic resonance imaging (MRI).Johns Hopkins Medicine.Breast biopsy.American Cancer Society.Breast density and your mammogram report.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Memorial Sloan Kettering Cancer Center.Anatomy of the breast.National Cancer Institute.Dense breasts: answers to commonly asked questions.Breastcancer.org.Dense breasts.American Cancer Society.Breast density and your mammogram report.Centers for Disease Control and Prevention.About dense breasts.Johns Hopkins Medicine.My doctor says I have dense breasts: what are dense breasts?Centers for Disease Control and Prevention.What is a mammogram?U.S. Food and Drug Administration.Important Information: Final Rule to Amend the Mammography Quality Standards Act (MQSA).Centers for Disease Control and Prevention.Screening for breast cancer.Breastcancer.org.When to get a mammogram.MD Anderson Cancer Center.Dense breast tissue: what it is, and what to do if you have it.Johns Hopkins Medicine.Breast magnetic resonance imaging (MRI).Johns Hopkins Medicine.Breast biopsy.American Cancer Society.Breast density and your mammogram report.
Memorial Sloan Kettering Cancer Center.Anatomy of the breast.
National Cancer Institute.Dense breasts: answers to commonly asked questions.
Breastcancer.org.Dense breasts.
American Cancer Society.Breast density and your mammogram report.
Centers for Disease Control and Prevention.About dense breasts.
Johns Hopkins Medicine.My doctor says I have dense breasts: what are dense breasts?
Centers for Disease Control and Prevention.What is a mammogram?
U.S. Food and Drug Administration.Important Information: Final Rule to Amend the Mammography Quality Standards Act (MQSA).
Centers for Disease Control and Prevention.Screening for breast cancer.
Breastcancer.org.When to get a mammogram.
MD Anderson Cancer Center.Dense breast tissue: what it is, and what to do if you have it.
Johns Hopkins Medicine.Breast magnetic resonance imaging (MRI).
Johns Hopkins Medicine.Breast biopsy.
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