Skip to content
My WebMD Sign In, Sign Up

Breast Cancer Health Center

Font Size

Understanding Breast Cancer and Mammograms

What if the radiologist sees something suspicious on your mammogram?

The fear this scenario evokes is real, but facts may help calm it. Most abnormalities on a mammogram are not breast cancer.

Recommended Related to Breast Cancer

What I Learned from Breast Cancer

One writer reveals what it's really like to live with the disease day-to-day — and honors the woman who helped her through the darkest moments. Last October, REDBOOK asked readers to send in their stories of how breast cancer had touched their lives — whether they themselves had the disease or had witnessed a loved one facing it down. The entries we received were poignant and powerful, making it difficult to select the grand-prize winner. Its author, Lauren Reece Flaum, 48, was...

Read the What I Learned from Breast Cancer article > >

On a screening mammogram, questionable abnormalities sometimes require additional evaluation. With further examination (imaging studies and/or biopsy), most of these abnormalities are found to be normal breast tissue or benign (non-cancerous) tissue.

What Is a Screening Mammogram?

The American Cancer Society recommends yearly screening mammograms starting at age 40. However, the U.S. Preventive Services Task Force (USPSTF) does not recommend screening for women in their 40s. For women between the ages of 50 and 74, USPSTF experts say women should have mammograms every two years and do not recommend screening at all after age 74.

When you need a mammogram is a personal decision between you and your doctor. If you're over 40, talk to you doctor about when you should begin mammogram screening.

In a screening mammogram, each breast is X-rayed in two different positions: from top to bottom and from side to side. When a mammogram image is viewed, breast tissue appears white and opaque and fatty tissue appears darker and translucent.

What if Something Looks Abnormal?

Potential abnormalities are found in up to 11% of women who have screening mammograms. This small group of women needs further evaluation that may include diagnostic mammography, breast ultrasound, or needle biopsy. Of those women asked to return for further testing, 20% to 50% will have breast cancer.

After the additional evaluation is complete, most of these women will be found to have nothing wrong.

What Is a Diagnostic Mammogram?

Diagnostic mammograms differ from screening mammograms in that the examination focuses specifically on an area of breast tissue that appeared abnormal in a screening mammogram. Diagnostic mammograms are also done for women who haven't had a screening mammogram but may be showing signs or symptoms of something abnormal in the breasts.

Depending on the potential abnormality, different studies may be done. In some women, only additional mammographic images are needed. In other women, additional mammographic images and an ultrasound are done.

How Does an Abnormality Appear on a Mammogram?

A potential abnormality on a mammogram may be called a nodule, mass, lump, density, or distortion.

  • A mass (lump) with a smooth, well-defined border is often benign. Ultrasound is needed to characterize the inside of a mass; if the mass contains fluid, it is called a cyst.
  • A mass (lump) that has an irregular border or a star-burst appearance (spiculated) may be cancerous; a biopsy is usually recommended.
  • Microcalcifications (small deposits of calcium) are another type of abnormality. They can be classified as benign, suspicious, or indeterminate. Depending on the appearance of the microcalcifications on the additional studies (magnification views), a biopsy may be recommended.

How Accurate Is Mammography?

Mammography is 85% to 95% accurate. Mammograms have improved the ability to detect breast abnormalities before they are large enough to be felt. Also, the accuracy of mammography improves as the patient ages. 

Accuracy rates may improve with more widespread use of three-dimensional mammography. Initial research showed that 3D mammography, used along with standard digital mammograms, bumped up breast cancer detection rates and decreased the number of women who had to return for more tests because of a suspicious mammogram finding.

WebMD Medical Reference

Reviewed by Sujana Movva, MD on October 25, 2012

Today on WebMD

Breast Cancer Overview
From self-exams and biopsies to reconstruction, we’ve got you covered.
Dealing with breast cancer
Get answers to your questions.
 
woman having mammogram
Experts don’t agree on all fronts, but you can be your own advocate.
woman undergoing breast cancer test
Many women worry. But the truth? Most abnormalities aren’t breast cancer.
 
Breast Cancer Treatments Improving
VIDEO
Resolved To Quit Smoking
SLIDESHOW
 
Woman getting mammogram
Article
Screening Tests for Women
SLIDESHOW
 
ovarian cancer overview slideshow
SLIDESHOW
serious woman
Article
 
what is your cancer risk
HEALTH CHECK
10 Ways to Revitalize Slideshow
SLIDESHOW