The fear of an abnormal mammogram result is legitimate. But don't be too alarmed if the radiologists finds something suspicious in your X-rays. Most abnormalities found in mammography aren't breast cancer. With further examination (imaging studies and/or biopsy), most of these abnormalities are found to be normal breast tissue or benign (non-cancerous) tissue.
In a screening mammogram, whether it is by film or digital, each breast is X-rayed 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.
The American Cancer Society recommends yearly screening mammograms starting at age 40. However, the U.S. Preventive Services Task Force (USPSTF) doesn't recommend regular mammography screening for women in their 40s. The USPTF recommendation is a baseline mammogram at age 40, and then a mammogram every two years beginning at age 50 and ending at age 74. Talk to your health care provider to determine how often you should get a mammogram.
What if Something Looks Abnormal on a Mammogram?
Potential abnormalities are found in 6% to 8% of women who have screening mammograms. This small group of women needs further evaluation that may include diagnostic mammography, breast ultrasound, or needle biopsy.
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 exam focuses specifically on an area of 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 performed. In some women, only additional images are needed. In other women, additional images and a breast ultrasound may be recommended.
How Does an Abnormality Appear on a Mammogram?
A potential abnormality on a mammogram may be called a nodule, mass, lump, density, or distortion. They may look like a:
Mass (lump) with a smooth, well-defined border -- this is often benign (non-cancerous). Ultrasound is needed to characterize the inside of a mass (for example, if the mass contains fluid, it is called a cyst).
Mass (lump) that has an irregular border or a star-burst appearance (spiculated) -- this may be cancerous and 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, a biopsy may be recommended.
How Accurate Is Mammography?
Mammography is 85% to 90% accurate. Those odds may improve with more widespread use of three-dimensional mammography. Mammograms have improved the ability to detect breast abnormalities before they are large enough to be felt during a breast examination.
However, it is possible for a mass to be felt but not appear on a mammogram. Because of this, your health care provider should evaluate any abnormality that you feel when examining your breasts. A diagnostic mammogram or biopsy may be recommended.