You’ve just received your mammogram results. The report inside the envelope says that you have “dense breast tissue.” But what does that mean, and should you be concerned?
Dense breast tissue is very common, affecting about 40% of women nationwide. There’s nothing clinically wrong with having dense breasts. But it can make it harder for doctors to find early signs of breast cancer, which is why you may need additional imaging tests.
To give you peace of mind, the team at Northwest Breast Imaging Center in Post Falls explains exactly what having dense breasts means, the risks they may bring, and the steps you can take to protect your breast health.
What is dense breast tissue?
A woman’s breasts include three types of tissue. Fatty tissue is a filler that gives breasts their shape. Glandular tissue contains glands that produce milk. And fibrous tissue connects fatty and glandular tissue.
The amount of each type of tissue is different in each individual. If you’ve been told you have dense breasts, it means that you have more fibroglandular tissue and less fatty tissue.
What’s the relationship between breast density and cancer risk?
Having dense breasts raises your odds of developing breast cancer. The average woman in the U.S. has a 13% risk of developing breast cancer in her lifetime, according to the American Cancer Society. Women with dense breasts have a 15% to 20% greater risk of developing breast cancer and having a false-negative mammogram.
One reason for the increased risk is that breast cancer is harder to detect in women with high levels of breast density. That’s because both dense tissue and tumors show up as white in a traditional mammogram, while fatty tissue appears grey or black. As a result, breast abnormalities could be obscured, potentially leading to a delayed diagnosis.
How can I tell if I have dense breasts?
You can’t tell that you have dense tissue by the look or feel of your breasts. The only way to know for sure is to have a mammogram. However, these factors can help you determine whether you’re at risk:
- Low body fat. Women with a lower body mass index (BMI) are more likely to have dense breasts than those who are overweight.
- Age. Breast density tends to decrease as you age, which is why younger women are at higher risk for having breast dense tissue.
- Hormonal changes. Pregnancy, menopause, and some types of birth control can increase your breast density. So can hormone replacement therapy.
- Genetics. If your mom or sister has been diagnosed with dense breast tissue, it’s more likely that you have it, too.
I’ve been told I have dense breasts, but I don’t understand my report. Can you help?
This is a common concern. Since 2024, the Food and Drug Administration (FDA) has required that women receive a letter after their mammogram that clearly states whether their breasts are “dense” or “not dense.”
If you look at your mammogram report in your patient portal, however, you may see some more technical language. That language describes one of the four categories of breast density based on the Breast Imaging Reporting and Data System (BI-RADS) guidelines. Here’s what that language means:
- Type A – “The breasts are almost entirely fatty.” This means your breasts contain mostly fatty tissue and are not dense. It’s found in about 10% of women.
- Type B – “There are scattered areas of fibroglandular density.” This means your breasts contain mostly fatty tissue, with some areas of connective tissue. You do not have dense breasts. It’s found in about 40% of women.
- Type C – “The breasts are heterogeneously dense, which may obscure small masses.” That means you have higher levels of thick glandular and connective tissue, and you do have dense breasts. It’s found in about 40% of women.
- Type D – “The breasts are extremely dense, which lowers the sensitivity of mammography.” This means your breasts are mostly made up of glandular and fibrous tissue, and that you do have dense breasts. It’s found in about 10% of women.
What type of mammogram is best for a woman with dense breasts?
A three-dimensional (3D) mammogram (also called tomosynthesis) is typically preferred over a standard two-dimensional (2D) mammogram for women with dense breast tissue.
While a 2D mammogram takes flat images of your breast from two angles, a 3D mammogram takes images from several angles, which are then combined to create a 3D image. This imaging method gives your radiologist clearer, more detailed images, making it easier to find and diagnose breast cancer that could be “hiding” inside dense breast tissue.
All women between age 40 and 80 should receive an annual screening mammogram, according to guidelines from the Society of Breast Imaging. 2D mammograms are covered by all insurers. Most insurers also cover 3D mammograms, but some plans require a higher out-of-pocket fee than with a 2D mammogram. Talk with your doctor about the type of screening that’s best for you, and check with your insurer to verify coverage.
What other tests might I need?
If you have dense breasts, your doctor may recommend other tests in addition to a 3D mammogram. Advanced screening tools available to women in the Inland Northwest include:
- Breast ultrasound. When used together with a mammogram, breast ultrasound can give radiologists more detailed findings. In an ultrasound image, tumors appear dark against white tissue, aiding detection of abnormalities.
- Breast MRI. The contrast dye used in MRI images can help doctors find hard-to-spot cancers.
Where can I find 3D mammograms and other tests in North Idaho?
Northwest Breast Imaging Center in Post Falls is dedicated to providing a convenient patient experience. Our center includes the latest breast health technology, including two 3D mammogram machines, breast ultrasound and breast MRI.
We pride ourselves on creating a mammogram experience like no other. You’ll feel cared for from the moment you walk through our door. You’ll wear a robe, not a paper gown. Your privacy will be respected. And you will receive care from a team of radiologists and technologists who devote 100% of their time to breast health.
When you’re ready for your annual mammogram, we’re here for you. Call us today at 208-770-3540 and we’ll get you seen in days, not weeks or months.