Breast Cancer Diagnosis
Once breast cancer is suspected, doctors use the following diagnostic tests.
A diagnostic mammogram is used to evaluate a woman with a breast problem or symptom or an abnormal finding on a screening mammogram. It usually includes additional views of one or both breasts.
Seattle Cancer Care Alliance (SCCA) was the first in the region to offer digital mammography, a technique that captures X-ray images digitally for a more accurate diagnosis. Studies have shown that digital mammography detects up to 28 percent more cancers than traditional mammography. For more information about mammography at SCCA, check out the digital mammography section of our Web site.
If your mammogram turns up with anything suspicious, you may be asked to have an additional mammogram or an ultrasound. Ultrasound uses high-frequency sound waves to form an image that is displayed on a video screen and photographed for analysis.
Similar to the test doctors use to look at babies during pregnancy, breast ultrasound is used to evaluate lumps that are hard to see on a mammogram. Because of the ways different substances interact with sound waves, ultrasound can often reveal whether a lump is a solid mass or a fluid-filled, non-cancerous cyst.
Ultrasounds are also used to assist in procedures like ultrasound-guided needle biopsies. Ultrasound is not used for routine breast cancer screening because it does not consistently detect early signs of cancer and it frequently leads to the need for biopsy of non-cancerous areas.
Magnetic Resonance Imaging
SCCA has long been a leader in the diagnosis and care of breast cancer, most recently in the use of MRI as a diagnostic tool. According to a study led by SCCA’s Dr. Constance D. Lehman, MD, PhD, MRI scans of women who were diagnosed with cancer in one breast detected over 90 percent of cancers in the other breast that were missed by mammography and clinical breast exam at initial diagnosis. In conjunction with this news, the ACS announced new recommendations for use of MRI for women at increased risk for breast cancer. An expert panel, of which Lehman is a member, recommended annual screening using MRI in addition to mammography for women with a 20 percent or greater lifetime risk for the disease. For more information about the use of MRI to detect breast cancer, see magnetic resonance imaging in our digital mammography section.
When a screening or a diagnostic procedure finds an abnormality that could be cancer, a biopsy may be performed. In a biopsy, a doctor removes a sample of cells from the suspicious area. That sample is then examined under a microscope.
A biopsy is the only way to tell if cancer is really present. A biopsy can also reveal details about the cancer, such as the grade and whether the cancer is hormone-receptor positive. These details influence treatment decisions.
Fine Needle Biopsy
A fine-needle biopsy involves extracting fluid or cells from a lump that can be felt or seen with ultrasound or on a mammogram. A local anesthetic numbs the area before the needle is inserted. If you have a cyst, fluid will come out and the lump will disappear. If the needle extracts cells, the sample is inspected by a pathologist to determine if it is benign (not cancer) or malignant (cancer).
A core biopsy is nearly the same as the fine needle biopsy, but a larger needle is used to remove a small cylinder of breast tissue.
Stereotactic Needle Biopsy
This type of biopsy is done when the lump is so small that the doctor cannot insert the biopsy needle accurately. In this procedure, you lie face down on a special table with an opening that lets your breast hang down. A mammogram shows the location of the lump and a computer guides the needle.
In this type of biopsy, all or part of a breast lump is removed surgically for microscopic examination to determine whether cancer is present.
During surgery for breast cancer, women may also have one or more lymph nodes removed and biopsied to check whether cancer cells have spread into the lymph system.