What to Expect at Your Next Mammogram

What Do Breast Masses Look Like on a Mammogram?

Normal Breast Tissue on a Mammogram

Normal Fatty Breast Tissue
What does a normal mammogram look like and what do abnormal changes look like?. National Cancer Institute


5 Most women will have their first mammogram around the age of 40, and this can serve as a good baseline from which to compare your images in the future.

There are a number of different breast cancer screening guidelines, which vary depending on the organization making the recommendations. The American College of Obstetrics and Gynecology recommends annual screenings starting at age 40. The American Cancer Society recommends yearly mammograms between the ages of 45 and 54, and the U.S. Preventive Services Task Force recommends mammograms every other year between the ages of 50 and 74. The "best choice" for you is that which you and your doctor decide upon based on your specific risk factors and wishes.

Having a baseline mammogram regardless of the frequency of your mammograms is very helpful. Over time, a woman's breasts can change especially after childbirth, following a breast biopsy, or with breast implants. It is not uncommon to get benign lumps, cysts, masses, calcifications, or dense tissue. Images shown are of actual mammograms courtesy of the National Cancer Institute.

breast cancer

Mammograms help with early detection and screening for breast cancer. The black and white areas on a mammogram image correspond to normal fatty tissue and denser breast tissue with ducts and lobes, respectively. Breast masses will appear white because they are denser than other features in the breast.

This image is a mammogram of a normal fatty breast, typical of older women, that does not have a lot of dense tissue. A mammogram searching for abnormal lesions, benign lumps, or breast cancer is more accurate when performed on women with non-dense breasts, usually older women. 

Normal Dense Breast Tissue on a Mammogram

Normal Dense Breast Tissue
Mammogram showing dense but normal breast tissue. National Cancer Institute

Young women, especially those who have not had children, usually have dense and rather firm breast tissue. A dense breast makes a mammographic image difficult to read. Mammography equipment can be adjusted to image dense or fatty tissue, but mammograms are considered most accurate on fatty tissue and older women.

This mammogram image shows two mammograms of normal dense breasts. The dark areas are fatty tissue, the light areas are denser tissue which contains ducts, lobes, and other features. Lighter areas of a mammogram reveal breast tissue that may be glandular (part of the milk system) or breast masses.

Premenopausal women, especially women who have never been pregnant, may have dense breast tissue. Because fatty breasts are easier for a mammogram to see through, dense breast tissue can sometimes hide outlines of areas that need closer study. If a particular area needs a better image, an ultrasound is usually the next step.

For young women with a strong family history of breast cancer, or are known to have genetic mutations which increase risk, an MRI can sometimes provide much better images when dense breast tissue is present.

Breast Calcifications on a Mammogram

Breast Calcifications on a Mammogram
Mammogram showing the appearance of calcifications. National Cancer Institute

In this mammogram image, the dark areas are normal fatty breast tissue and the lighter areas are denser tissue. The whiter spots are calcifications, which are indicated by the red arrows. The breast calcifications are in ductal patterns, as calcification occurs along the milk ducts of the breast. This is considered an abnormal mammogram, but not necessarily cancerous.

Microcalcifications are tiny bits of calcium that may show up in clusters or in patterns (like circles) and are associated with extra cell activity in breast tissue. Usually, the extra cell growth is not cancerous, but sometimes tight clusters of microcalcifications can be an early warning sign or precancerous cells. Scattered microcalcifications are usually a sign of benign breast tissue.

In this case, the woman was advised to have a follow-up mammogram in three months for a comparison. If a woman has a lump associated with calcifications, however, immediate further testing is needed.

Fibrocystic Breast Tissue on a Mammogram

Fibrocystic Breast Tissue
Mammogram showing the appearance of fibrocystic breast tissue. National Cancer Institute

A  fibroadenoma or cyst is a benign breast mass that can appear in fibrocystic breast tissue. These can appear alone, or in groups, and are common on mammograms appearing as a dense mass. This mammogram shows thickened areas that are typical of fibrocystic changes. You can also see some ducts, by the patterns they form.

Normal fibrocystic changes in your breast can be affected by monthly hormonal fluctuations that may taper off in menopause. About half of all women experience fibrocystic changes in their breasts, especially during their fertile years.

Fibrocystic changes in the breast are usually not a sign of disease and do not require treatment. These changes can sometimes cause breast pain and lumpiness, so if this becomes a problem, visit your doctor for help.

Breast Tumor on a Mammogram

Breast Cancer Tumor on Mammogram
Mammogram showing a probable breast tumor. National Cancer Institute

This mammogram shows dark areas of normal fatty breast tissue. Lighter areas are dense breast tissue that includes ducts and lobes. The whitest area is the densest, showing a cancerous tumor, indicated by a red arrow in the lower right corner of the image.

A cancerous tumor in the breast is composed of a mass of cancer cells that are growing in an abnormal, uncontrolled way. The tumor may invade surrounding tissue, or it may shed cells into the bloodstream or lymph system. If the tumor cells migrate beyond the original site and spread to other parts of the body, it is considered metastatic breast cancer.


A breast tumor usually requires treatment by surgery and may require chemotherapy, radiation, targeted biological therapy, and/or hormonal therapy. When a breast tumor is found in an early stage of breast cancer, it is more likely to be successfully treated, to prevent its spread or recurrence.

Breast Implant on a Mammogram

Mammogram With Implants
Appearance of a breast implant on mammogram. Image © Pam Stephan

This mammogram shows two views of a breast following a mastectomy with reconstruction with a silicone breast implant. This woman had been successfully treated for a type of breast cancer called invasive ductal carcinoma. Mammograms taken after a diagnosis of breast cancer are important screening tests. There is no evidence of breast cancer in these images.

Mammograms can be performed on breast implants if less compression is used than what is required on natural breast tissue. In both views of this breast reconstruction, the implant appears as a light, smooth-sided area. This implant is inserted into a pocket of the chest wall. The chest wall muscle appears as the medium-dark area just outside the implant.

Note that the overhead view, called the cranial-caudal view, shows a smaller area than the diagonal view, called the mediolateral view. Having these two views is very helpful for doctors to determine breast health. 

Mammogram and MRI Image Comparisons

Mammogram and MRI Breast Images Comparison
Mammogram Details Mammogram and MRI Breast Images Comparison. National Cancer Institute

s.Mammograms are the primary screening used for breast health, but for greater detail of a particular area, an MRI (magnetic resonance imaging) can capture a higher contrast, detailed image. Breast MRIs are much more expensive than mammograms, and the equipment is not as widely available. For this reason, MRI technology is not used for routine breast screening but primarily used to diagnose abnormal tissue or screen those who are at a very high risk of developing breast cancer.

These two side-by-side comparisons show a mammography on the left and an MRI on the right. The MRI image illustrates the deeper level of detail, which is extremely helpful to confirm a diagnosis.

If a mammogram has shown a breast mass that seems worrisome, an MRI or ultrasound can provide more accurate information. If the MRI confirms that a mass looks cancerous, the next step is a biopsy

Bottom Line on Mammogram Images

Mammograms can be a helpful adjunct in the early diagnosis of breast cancer and may find cancers which are not yet palpable. At the same time, a concern of overdiagnosis has been raised in recent years. For example, the presence of microcalcifications, while sometimes alerting your physician to underlying cancer, has many benign causes as well.

Added to this is the varying recommendations by several organizations, as well as the differing opinions of many doctors. What this comes down to is that you need to be your own advocate in your health care. Learn about the limitations of a mammogram. If you are concerned due to a strong family history of breast cancer, talk to your doctor about the option of having a breast MRI. If you develop a lump, a breast ultrasound is sometimes more helpful in making a diagnosis.

While all of this is important, the best "treatment" is to prevent cancer from occurring in the first place. While many cancers arise for now apparent reason, and we know many extremely healthy women who develop breast cancer, there are some things you can do to lower your risk. Eating a healthy diet rich in fruits and vegetables is a start. Engaging in regular exercise is also a must. Studies are also suggesting that women with low vitamin D levels may have an increased risk. At your next appointment, ask your doctor to check your vitamin D level. If it is low she can help you find ways to raise it, whether that means taking a little more time in the sun or taking a vitamin D supplement.