Mammograms provide a look inside the breast to help doctors (radiologists) detect breast cancer, often in the early stages when it’s most treatable. But it’s not uncommon that they see something that looks like it might be cancer—a “finding” that could end up being completely normal, but that needs to be further tested to be sure. These tests include diagnostic mammograms, breast ultrasounds, breast MRIs, and breast biopsies.
“I think it's important for women to know that, if they get recalled for additional imaging tests because there's a possible finding on a routine screening mammogram, they shouldn't panic,” says Yale Medicine radiologist Regina Hooley, MD. In fact, she says, “The majority of findings will turn out to be noncancerous, not suspicious, nothing to worry about.”
At Yale Medicine, we have a team of radiologists who specialize in breast imaging. “We are multi-modality,” explains Dr. Hooley, “in that we not only read mammograms, but we also perform breast ultrasounds, breast MRIs, and breast biopsies.” Patients can often speak to the radiologists after the testing is complete and get immediate results.
Having a team of radiologists who specialize in breast imaging increases accuracy, which is why we have a very low recall rate, she says. For the patient, this means fewer false alarms, less retesting, less time and costs—and less worry.
What are some common breast imaging findings that are benign?
Some of the noncancerous breast findings visible on mammograms are as follows:
- Simple cysts: These are fluid-filled sacs, which are normal. “An ultrasound is really good at diagnosing normal, simple cysts that can mimic the appearance of a cancer on the mammogram,” says Dr. Hooley. However, occasionally other types of cysts may need to be followed with a repeat ultrasound or aspirated (drained).
- Fibroadenomas: These benign growths are very common in the breast. “Fibroadenomas can look like a lot of different things, and sometimes they look absolutely normal on the mammogram. But they also can have features that may look like a cancer on the mammogram or ultrasound, so we may need to perform a needle biopsy to be sure.”
- Fibrotic tissue: A woman’s breasts and their consistency naturally change over her lifetime. Some may develop noncancerous fibrous tissue within the normal glandular tissue. These changes are benign, even though a focal area of fibrosis can look like a cancer on the mammogram. Ultrasound and/or needle biopsy may be necessary.
- Calcifications: These look like small white dots on a mammogram and are usually normal. Many women have benign (noncancerous) larger macrocalcifications in their breasts. On the other hand, tiny microcalcifications may be a sign of cancer. Benign calcifications may be due to multiple causes including fibrocystic changes, inflammatory changes, or previous injury to the breast. Worrisome microcalcifications that may be due to breast cancer are arranged in a certain pattern and shape. Radiologists may choose to do more testing for further evaluation or recommend you have a follow-up mammogram in a few months’ time to look for breast changes. Also, some products, such as deodorant, lotion, and powders, may contain materials that can mimic the appearance of microcalcifications, making the mammogram more difficult to interpret. For this reason, it is important not to use these skin products before your mammogram appointment.
- Dense breast tissue: Breast composition includes two kinds of tissue: glandular and fatty. Dense breasts consist mostly of white glandular tissue. This type of tissue makes it harder for radiologists to see cancers, which usually also appear as white areas. This is why breast ultrasound is an optional extra screening test that can be used in addition to the mammogram in women with dense breasts. Your mammogram report will state whether or not your mammogram shows dense breast tissue.
What mammogram findings indicate possible breast cancer?
A radiologist looks for masses, irregular breast tissue, and/or calcifications that have certain patterns and characteristics that may be a sign of abnormally dividing cancer cells. Additional imaging tests are needed to determine whether an abnormal screening mammogram finding is benign or malignant.
What additional imaging tests would I need if there’s a finding on my screening mammogram?
Your radiologist typically recommends that you come back for a diagnostic mammogram and/or breast ultrasound, which can provide more information about what appears on a screening mammogram.
Your doctor may also recommend that you be monitored more closely over time—even if the finding is ultimately benign—to check for changes and to help monitor your breast health. (Usually the radiologist will recommend a follow-up exam in 6 months.) Detecting cancers early allows for earlier treatment and more successful outcomes. Your radiologist will advise your doctor via the radiology report if she wants you to come back to the Breast Center for more testing, which may include some of the following:
- Diagnostic mammogram: During a diagnostic mammogram, the mammographer takes additional images beyond what is done during a regular routine screening. A diagnostic mammogram includes special views to best see and characterize the finding initially seen on screening. These images give the radiologist additional information to evaluate for breast cancer.
- Breast ultrasound: Cancers often appear as dark (rather than white) spots on an ultrasound. This can make it easier for radiologists to find small cancers. This is especially true when detecting tumors within dense breast tissue. Breast ultrasound can also determine if an abnormality seen on the mammogram is a cyst or solid mass.
- Breast MRI: An MRI is a highly sensitive and accurate tool for detecting breast cancers. It is most often recommended for screening women who are at very high risk for breast cancer because it is more invasive (contrast dye needs to first be injected intravenously into the breasts). When a new breast cancer is diagnosed, breast MRI may also be advised for further evaluation.
- Breast biopsy: During this procedure, a small piece of tissue is removed and sent to a pathology lab to be evaluated under a microscope to determine if its cells are malignant (cancerous) or benign (noncancerous). A breast biopsy may be done under stereotactic/tomosynthesis (mammography), ultrasound, or MRI guidance. The breast biopsy is frequently performed by the radiologist and is a simple outpatient procedure that typically takes less than one hour to perform.
What’s unique about Yale Medicine’s approach to evaluating breast findings?
Our specialists are highly experienced at reading both screening and diagnostic mammograms using the latest 3D technology. We perform breast ultrasounds and MRIs, as well as guided-imaging breast biopsies. We use a multi-modality approach and work closely with the Yale Medicine breast surgeons and oncologists.
“We use the latest technology to significantly enhance accuracy and improves the patients’ experience,” says Dr. Hooley, “so we detect more breast cancers early.”