Diagnostic vs. Screening Mammograms

Mammograms are a critical tool in the early detection of breast cancer, helping identifying potential concerns before symptoms arise. These low-dose X-rays of the breast, called screening mammograms, are the best way to detect breast cancer in the earliest stages, when your breast cancer treatment is most likely to be successful.

But mammograms aren't used just for screening. Your doctor may order a second type of mammogram, called a diagnostic mammogram, if your screening mammogram results are suspicious or if you’re experiencing signs and symptoms of breast cancer.

Read on to learn more about screening vs. diagnostic mammograms, and when and why you may need a mammogram as part of your medical care.

Why Should I Have A Mammogram?

Mammography uses low-dose X-rays to show abnormal areas or tissues in the breast before a person (often a woman, though men can have breast cancer too) has noticeable symptoms of breast cancer.

A mammogram is done as a screening test if you don’t have breast problems. It can check for breast cancers, noncancerous or benign tumors, and cysts before they can be felt.

A mammogram also may be done if you have breast problems such as a lump, pain or nipple discharge.

"Regular self-exams are helpful, but routine mammograms are the best way to detect breast cancer early, even before symptoms appear," said Ajita Narayan, MD, a board-certified hematologist and oncologist with Franciscan Health Cancer Center Lafayette.

When Should A Screening Mammogram Be Done?

The American Cancer Society recommends this breast cancer screening schedule for women at average risk of breast cancer:

• Women between 40 and 44: Optional mammogram every year.
• Women 45 to 54: Yearly mammograms.
• Women 55 and older: Yearly mammograms or can switch to a mammogram every other year. Screening should continue as long as a woman is in good health and is expected to live at least 10 more years.

Risk factors for earlier breast cancer screening

"If you have a family history of breast cancer or other risk factors, you may need to start earlier," said Dr. Narayan. "It's always a good idea to have a conversation with your doctor to create a personalized screening plan. Early detection can make a huge difference in treatment options and outcomes."

Specific risk factors that increase risk of early breast cancer might prompt young women to talk with their doctor about getting screening mammograms earlier. These breast cancer risk factors include:

• A family history of breast cancer
• Genetic mutations like BRCA1 or BRCA2
• Dense breast tissue
• Radiation exposure to the chest at a young age, such as during treatment for another cancer
• Unhealthy lifestyle choices

What Is A Screening Mammogram Like?

During a mammogram, the breasts are each placed in a special machine between two plates. The plates move together to compress the breast tissue, so it’s easier for the X-ray to obtain a clear image.

The images are stored on a computer where they can be viewed and analyzed by the radiologist and a woman’s doctor.

What's The Difference Between A Diagnostic Mammogram And A Screening Mammogram?

The difference between screening vs. diagnostic mammogram has to do with the reason the mammogram has been ordered.

Screening mammograms

Screening mammograms are recommended starting at age 40 and annually thereafter. Screening mammograms are done routinely to visualize any breast changes in women without signs of breast cancer, in order to find a tumor before it can be felt by touch. In the case of a screening mammogram, the woman may have had a physical exam by her physician, there's been nothing found on the physical exam, and the woman has no complaints over any part of her breasts.

A screening mammogram is just a routine screening. The procedure is quick and relatively painless.

Diagnostic mammograms

A diagnostic mammogram is a little different from a screening mammogram. Most commonly there is something on the physical exam that the clinician has either felt or that the patient has felt, or it's an area of concern. 

Your doctor might ask you to get a diagnostic mammogram if you have:

• A lump in your breast
• Breast pain
• Nipple thickening or discharge
• A change in breast size or shape
• Skin dimpling on the breast that may resemble an orange peel
• Redness, flaking or thickened skin of the breast or nipple
• Swollen lymph nodes under the arm or near the collarbone

After your diagnostic mammogram, a breast imager will look at the study and provide results. A breast ultrasound or breast MRI may also be ordered.

Are Diagnostic Mammograms Better Than Screening Mammograms?

It is a myth that diagnostic mammograms are better than screening mammograms. The same machine is used for both tests. A diagnostic mammogram usually takes a few minutes longer than a screening mammogram because more images are taken.

Are 3D Mammograms Different From Screening Or Diagnostic Mammograms?

3D mammograms are often used with women with dense breast tissue. 3D mammography can be used for both screening and diagnostic mammograms.

What Should I Do If My Last Mammogram Was Done Elsewhere?

If you’re having your annual mammogram completed with a different health care system than prior years, you should always make sure to have images sent from prior facilities to the new facility. Comparing studies year-to-year is very important to see any changes in the breast. You can obtain medical records in one of two ways:

• Physically go to the facility where the mammogram was completed, and they will give you a disc with your prior images to take to your appointment.
• Call the facility and obtain a medical release form that you can fax or mail, if you’re unable to visit the facility in person. The imaging center can have the films sent to the location where you're going to have the mammogram.