Limitations of mammograms

Limitations of mammograms

A mammogram cannot prove that an abnormal area is cancer. To confirm cancer is
present, a small amount of tissue must be removed and looked at under a microscope.
This procedure, called a biopsy, is described in the section, "How is breast cancer
diagnosed?"
You should also be aware that mammograms are done to find breast cancer that cannot be
felt. If you have a breast lump, you should have it checked by your doctor and consider
having it biopsied even if your mammogram result is normal.
For some women, such as those with breast implants, additional pictures may be needed.
Breast implants make it harder to see breast tissue on standard mammograms, but
additional x-ray pictures with implant displacement and compression views can be used
to more completely examine the breast tissue.
Mammograms are not perfect at finding breast cancer. They do not work as well in
women with dense breasts, since dense breasts can hide a tumor. Dense breasts are more
common in younger women, pregnant women and women who are breastfeeding , but
any woman can have dense breasts.
This can be a problem for young women who are at high risk for breast cancer (because
of gene mutations, a strong family history of breast cancer, or other factors) because they
have a higher risk of developing breast cancer at a younger age. This is one of the reasons
that the American Cancer Society recommends MRI scans in addition to mammograms
for screening in these women. (MRI scans are described below.)
At this time, American Cancer Society guidelines do not contain recommendations for
additional testing to screen women with dense breasts who aren’t at high risk of breast
cancer.
For more information on these tests, also see the section, "How is breast cancer
diagnosed?" and our document, Mammograms and Other Breast Imaging Procedures.