After Your Mammogram: Understanding Your Results
A mammogram is a series of images made by an X-ray exam of your breast tissue. It’s used to find problems with your breasts such as breast cancer. Your healthcare provider will explain the results. Be sure to ask questions if you don’t understand what you are told. Your provider may advise more tests to check anything that looks suspicious. This is common. A call-back does not mean you have cancer.
The rating system
Only a doctor (radiologist) can interpret a mammogram. The technologist who gives the test can’t tell you the results. They also can’t discuss what they are looking at while doing the exam. Radiologists look for problems in the images. Then they take this information and sum it up in one number (score) when they send their findings to your healthcare provider.
Your mammogram results will be given a number of 0 through 6. This rating system is known as the Breast Imaging Reporting and Data System (BI-RADS). This system makes accurate communication and follow-up after the tests much easier. Your healthcare provider will talk with you about your mammogram's category and what, if anything, you need to do next.
Making sense of it all
There are 6 categories for breast imaging results:
0: Your mammogram is still incomplete. The X-ray may have been cloudy. This makes it hard to read the images, for example. More information or imaging is needed to assign a true score.
1: This means your mammogram is negative. No signs of cancer were found. You should continue to have routine screenings.
2: This also means your mammogram is normal with no apparent cancer. But it means other non-cancerous (benign) findings such as cysts were found. You should continue routine screenings.
3: This means your mammogram is probably normal and the findings are most likely benign. But there is a slight (2%) chance of cancer. You will likely need a follow-up screening in 6 months.
4: This means the findings are suspicious. Your provider may advise that you have a biopsy.
5: The findings mean you are likely to have cancer. A biopsy is strongly advised for a correct diagnosis.
6: This means you’ve already been diagnosed with breast cancer and the pathologist has confirmed the diagnosis.
BI-RADS breast density report
Your report will also include a description of how much fibrous and glandular tissue is in your breasts, as opposed to fatty tissue. This is called breast density. The denser your breasts, the harder it can be to see abnormal areas on mammograms. Having dense breasts is very common. BI-RADS classifies breast density into 4 groups:
Breasts that are almost all fatty tissue
Breasts with scattered areas of dense tissue
Breasts made of more glandular and fibrous tissue, making it hard to see small tumors
Breasts that are extremely dense, making it hard to see tumors in tissue
If you have dense breast tissue, talk with your healthcare provider about what this means for you. Be sure that they know your health history. Also tell them if you know of anything in your history that increases your risk for breast cancer.
What happens if my mammogram results are abnormal?
Although lumps are usually not cancer, the only way to be certain is to have additional tests. Your healthcare provider will order more tests that can offer clearer, more detailed images of that area. These tests may include a focused mammogram, an ultrasound, or an MRI. If further tests show that the mass is solid, the healthcare provider may advise a biopsy. A biopsy is a procedure in which cells are removed from a suspicious area to check for cancer.
My mammogram described my breasts as being "heterogeneously dense, which may obscure small masses." What does this mean?
This means that you have moderately dense tissue. This is common and not a cause for concern. Sometimes dense tissue can make it harder to accurately read a mammogram. Your healthcare provider will go over different screening options with you, if needed.