What is a breast biopsy?
A biopsy is a procedure to remove a small sample of breast tissue from an area that appears abnormal on an image of the breast. The abnormality may be detected on a mammogram, sonogram or MRI. Our pathologists can then examine the tissue to determine whether it contains cancerous cells. Radiologists always perform biopsies using a minimally invasive, non-surgical biopsy approach. These include:
- ultrasound-guided biopsy
- stereotactic biopsy
- MR (magnetic resonance)-guided biopsy
We use ultrasound-guided breast biopsy when an abnormality requiring biopsy can be well seen on ultrasound. During the biopsy we will determine the exact location of the abnormality using real-time ultrasound images and will continue to image the breast while we advance a needle following administration of local anesthetic (lidocaine). Then we remove tissue samples to be evaluated by our pathologists. This allows us to observe the biopsy needle at all times during the procedure.
We use stereotactic (mammogram-guided) biopsy when an abnormality can be well seen with a mammogram but not well seen on a sonogram. During a stereotactic biopsy, the breast is positioned similar to how it is positioned for a mammogram. We then produce images of the breast from two different angles using the digital mammography machine. A computer calculates the exact location of the abnormality in the breast once we identify it on the computer screen. The biopsy device has a "guide" that places the needle precisely at this location following administration of local anesthetic (lidocaine). Then we remove tissue samples to be evaluated by our pathologists.
We use MRI (magnetic resonance imaging)-guided breast biopsy when we detect an area of concern seen on MRI but not on ultrasound. We usually perform an ultrasound after a identifying an abnormality on MRI; if the same finding is visible on ultrasound, we may perform an ultrasound biopsy instead. We use MRI to create images of the breast that enable us to guide a needle to the site of the abnormality following administration of local anesthetic (lidocaine). Then we remove tissue samples to be evaluated by our pathologists.
How do I get ready for the test?
If you are undergoing ultrasound-guided or stereotactic (mammogram-guided) breast biopsy no special preparation is needed. Leave your jewelry and other metal accessories at home if you will be undergoing an MRI-guided biopsy, as these can interfere with the magnet in the MRI scanner. Generally one week prior to biopsy medications that can affect clotting of the blood (aspirin-like drugs) and "blood thinners" are discontinued. In the case of blood thinners, this is coordinated in consultation with your health care provider.
What will happen during the test?
During an ultrasound biopsy you will lie on your back on the ultrasound table, and we will ask you to raise your arm and place it behind your head. We will inject a local anesthetic into the breast around the area to be biopsied. Once the area is numb the radiologist will guide the device—a fine needle, core (hollow) needle, or vacuum device—he/she will use to remove the tissue to the site and take a sample of tissue from the abnormality while viewing the target and the biopsy device in real time on the ultrasound monitor. This procedure usually takes about 30 minutes.
During a stereoscopic biopsy you will lie face down on a specialized table with an opening for your breast; or you will sit in a chair . The technologist assisting the radiologist will carefully compress your breast and then image it from two different angles. A computer will then use these two images to determine the correct location to place the needle for the biopsy. The radiologist uses a computer console next to the biopsy unit, and using computer guidance directs the needle to the site of the abnormality and will take several tissue samples. The procedure takes about one hour and is performed under local anesthetic. Most patients are able to return to their normal routine within 24 hours.
During an MRI-guided biopsy you will lie face down on the MRI table as you did for the initial MRI. We will insert an intravenous (IV) line into a vein in your hand or arm and will give you a contrast material as suring the prior MRI. Your breast will be gently compressed between two compression plates. Using computer software, we will measure the position of the abnormality and calculate the correct position and depth of the needle placement. We will numb the area around the abnormality with a local anesthetic, then will insert the biopsy needle, advance it to the abnormality, verify its position using MR imaging, then remove some tissue samples from the area. The procedure takes about one hour.
Are there any risks?
Following breast biopsy there is a very small risk of bleeding or infection, and some women also experience shoulder stiffness.
After the test
After a biopsy it may take a few days before the final tissue analysis (pathology report) is ready. A pathologist will examine your tissue sample and make a final diagnosis. If your biopsy results are negative, meaning we determine that the abnormal tissue is not cancerous, we will let you know immediately, and we will let you know if any follow up is necessary. If your biopsy results are positive, meaning we determine that the abnormal tissue is cancerous, we will help you understand the results and talk with you about the next steps in the process. We will refer you to a breast surgeon, who will meet with you to discuss surgical options, and to a medical oncologist who specializes in breast cancer, who will meet with you to discuss treatment options.