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Breast Cancer

Surgical Breast Biopsy

If exams or imaging tests show you might have breast cancer, your doctor may refer you for a breast biopsy to help find out for sure. Most often this will be a core needle biopsy (CNB) or a fine needle aspiration (FNA). But in some situations, such as if the results of a needle biopsy aren’t clear, you might need a surgical biopsy (sometimes called an open biopsy).

What is a surgical biopsy?

For this type of biopsy, surgery is used to remove all or part of a suspicious area so it can be checked for cancer cells.

There are 2 types of surgical biopsies:

  • An incisional biopsy removes only part of the abnormal area.
  • An excisional biopsy removes the entire tumor or abnormal area. An edge (margin) of normal breast tissue around the tumor may be removed as well, depending on the reason for the biopsy.

Preoperative localization to guide surgical biopsy

If the change in your breast can be felt, the surgeon can do the biopsy using their sense of touch as a guide.

But if the change can’t be felt and/or is hard to find, an imaging test such as a mammogram, ultrasound, or MRI may be done before the surgery to help place a wire or other localizing device (such as a radioactive or magnetic seed, or a radiofrequency reflector) into the suspicious area. This can help guide the surgeon the right spot. This is called preoperative localization.

For wire localization, your breast is numbed, and an imaging test is used to guide a thin, hollow needle into the abnormal area. Once the tip of the needle is in the right spot, a thin wire is put in through the center of the needle. A small hook at the end of the wire keeps it in place, while the other end of the wire remains outside of the breast. The needle is then taken out. You then go to the operating room with the wire in your breast. The surgeon uses the wire as a guide to the area to be removed. When this method is used, it is done the same day as your surgery.

In newer methods of localization, a localizing device is put into the suspicious area before the day of your surgery, so you don’t have to have it done the morning of your operation. Radioactive or magnetic seeds (tiny pellets that give off a very small amounts of radiation or that create small magnetic fields) or radiofrequency reflectors (small devices that give off a signal that can be picked by a device held over the breast) can be placed completely inside the breast (unlike the wire used for localization). Your surgeon can then find the suspicious area by using a handheld detector in the operating room.

What to expect if you have a surgical biopsy

During a surgical biopsy

Rarely, a surgical biopsy might be done in the doctor's office. But most often it's done in a hospital’s outpatient department or a surgical center. You are typically given local anesthesia (numbing medicine), along with intravenous (IV) sedation to make you drowsy. Another option is to have the biopsy done under general anesthesia (where you’re given medicine to put you in a deep sleep and not feel pain).

The skin of the breast is cut, and the doctor removes the suspicious area. You will likely need stitches after a surgical biopsy, and pressure may be applied for a short time to help limit bleeding. The area is then covered with a sterile dressing.

After a surgical biopsy

The biopsy can cause bleeding, bruising, or swelling. This can make it seem like the breast is larger after the biopsy. Most often, this is nothing to worry about, and the bruising and swelling will go away over time. Your doctor or nurse will tell you how to care for the biopsy site, how much (and for how long) you might need to limit your activities, and when you might need to contact them if you’re having any issues.

A surgical biopsy may leave a scar. You might also notice a change in the shape of your breast, depending on how much breast tissue is removed.

What does a surgical biopsy show?

A doctor called a pathologist will look at the biopsy tissue under a microscope to check it for cancer cells.

Ask your doctor when you can expect to get the results of your biopsy. The next steps will depend on the biopsy results.

If no cancer cells are found in the biopsy, your doctor will talk to you about whether any other tests are needed, as well as when you need to have your next mammogram and any other follow-up visits.

If breast cancer is found, other lab tests might be done on the tissue to learn more about the cancer and how best to treat it. Your doctor will talk to you about these tests and about what the next steps will be. You might need to see other doctors, too. For more on this, see Understanding a Breast Cancer Diagnosis.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Chagpar AB. Techniques to reduce positive margins in breast-conserving surgery. 2021. UpToDate. Accessed at on October 14, 2021.

Joe BN, Esserman LJ. Breast Biopsy. 2021. UpToDate. Accessed at on October 14, 2021.

Last Revised: January 14, 2022

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