Breast density is currently a hot topic because legislation has passed in many states making it mandatory for clinics to inform women of their category of breast tissue density. This density notification is usually part of your mammogram results letter.
But what does breast density mean?
Imagine you are walking along a snow-covered trail with your coat that has pearl buttons on it. You catch your foot on some ice and as you jerk, you tear the pearls off your coat. You know there are five to find but it is impossible because you are looking for white pearls in a snowbank!
This is a good way to think of breast density. When you have extremely dense or heterogeneously dense breast tissue, it makes identifying worrisome findings more difficult on a mammogram.
Breast density types
There are four categories of breast density:
- Extremely dense
- Heterogeneously dense
- Scattered fibroglandular densities
- Fatty breasts
Your breasts are made up of three different layers of tissue: adipose, which is fat, and shows up dark on a mammogram, and fibrous and glandular tissues, which show up as white on your mammogram.
If you are considered to have heterogeneously or extremely dense breast tissue, the image looks similar to a snowball — all white.
This is important because the things a mammogram is trying to screen for, such as cysts, calcifications and cancer, also appear white on the mammogram image. Just to note: Mammogram findings give subtle characteristics that differentiate between worrisome and non-worrisome. However, they are not always easy to distinguish.
Seeing through the ‘snow’
In order to get the best images possible from a dense breast, the mammographer will need to get enough compression to separate the tissue layers to make the image less white. The theory is, the more we compress the breast, the more we are separating the layers, making it easier to see through the white.
If you have scattered fibrous glandular tissues, this means you have areas of dark and white, scattered throughout the breast. Again, the compression is important to separate those areas of white to see through this tissue for any abnormalities.
If your breasts are considered fatty, it means we see mainly dark breast tissue. If we see anything white, we flag this as a possible worrisome finding because you should not have any white in the breast if you have fatty breasts.
If you have more questions
The Edith Sanford Athena Breast Health Program is one resource for breast health questions. This program aims to help identify women who are at elevated risk for developing breast cancer. This is done through a Breast Health Questionnaire that is sent to patients each time they schedule a screening mammogram.
If you would like more information about a personalized breast cancer risk assessment, or how to lower your risk of developing breast cancer, please contact your local Edith Sanford Athena Breast Health Specialist.
- What you need to know about dense breast tissue
- 5 reasons to get a 3D mammogram
- Podcast: Genetics transform breast cancer screenings