Patient Basics: Wire Localization Biopsy of the Breast

Originally published by Harvard Health.

What is the test?

A wire localization biopsy is a type of surgical biopsy.

Sometimes an abnormal area will be seen on the mammogram that clearly should be tested for cancer or completely removed from the breast, but this area is not easily felt as a lump on examination. The mammography department can help your surgeon to find the area more easily by using a technique called “wire localization.”

In this technique, the radiologists (who have had the benefit of seeing the abnormal area on your mammograms) mark the abnormality with a wire that is inserted under your skin into the area of breast that is causing concern. Right afterward, the surgeon can meet you in the operating room and can use the wire to find the abnormal spot in your breast so that he or she can remove it.

For a surgical biopsy, the surgeon makes an incision in the skin and removes all or part of the abnormal tissue for examination under a microscope. Unlike needle biopsies, a surgical biopsy leaves a visible scar on the breast and sometimes causes a noticeable change in the breast’s shape. It’s a good idea to discuss the placement and length of the incision with your surgeon beforehand. Also ask your surgeon about scarring and the possibility of changes to your breast shape and size after healing, as well as the choice between local anesthesia and general anesthesia.

How do I prepare for the test?

You’ll undergo a breast exam and possibly a mammogram before the biopsy to determine where the lump is located. If you are having a sedative with local anesthesia, or if you are having general anesthesia, you’ll be asked not to eat anything after midnight on the day before the surgery.

Tell your doctor if you’re taking aspirin, NSAIDs, or any medicine that can affect blood clotting. You might have to stop or adjust the dose of these medicines before your test.

What happens when the test is performed?

The first part of this procedure occurs in the mammography department. Although you probably just recently had a mammogram, a radiologist will perform another one to find the abnormal area. While watching your x-ray on a screen, the radiologist will then decide where in your breast the abnormality must be. He or she will insert a needle into your breast in this area and will take another mammogram picture that shows the needle in place, to be sure the end of the needle is (hopefully) right in the middle of the area of concern. The needle might require some adjustment so that it is placed just right.

The needle is hollow and the radiologist can slide a small wire right through it. This wire has a tiny fishhook on its end so when the end of the wire reaches the point of the needle in your breast, it can grab onto your breast tissue and hold itself in place. Then the needle can be pulled out, sliding over the outside end of the wire and leaving the wire in your breast.

You will be taken to the operating room for the second part of the biopsy. You will have an IV (intravenous) line placed in your arm so that you can receive medicines through it. Your procedure may be done under either “local” or “general” anesthesia. Local anesthesia is similar to the kind most people get at the dentist — a numbing medicine is injected in a few places under the skin surface so that you won’t feel anything in the specific area that will be worked on during the surgery. General anesthesia, on the other hand, causes you to be asleep and unconscious during the procedure and is administered by an anesthesiologist. For general anesthesia, you breathe a mixture of gases through a mask. After the anesthetic takes effect, a tube may be put down your throat to help you breathe.

An incision will be made in your breast right where the wire sticks out of your skin. The surgeon will feel along the wire and separate the breast tissue from the wire until he or she finds where the end of the wire is hooked into your breast. The surgeon knows that it is the area right at the end of the wire that looks abnormal on your mammogram and needs removal. He or she will take out a small sample of breast tissue from the area surrounding the end of the wire.

The biopsy sample is sent to the pathologist. Depending on the circumstances, the pathologist might be able to make a preliminary diagnosis or tell the surgeon that a slightly larger sample is needed. All specimens will be preserved to be evaluated more thoroughly within the next couple days in the pathology department.

What risks are there from the test?

Following a surgical breast biopsy, you’ll have a short scar in the shape of a line. There may also be some distortion in the shape of the breast depending on its size, and the amount of tissue removed and its location. Expect to feel some soreness and swelling near the surgery site for a few days. There are also some risks associated with anesthesia.