Core Needle Breast Biopsy: About This Test

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What is it?

A core needle breast biopsy removes samples of breast tissue using a needle with a special tip. The samples are looked at under a microscope to check for cancer cells.

Why is this test done?

A core needle breast biopsy is most often done to check a lump found during a breast exam or a suspicious area found on a mammogram or other imaging.

How do you prepare for the test?

If you take a medicine that prevents blood clots, your doctor may tell you to stop taking it before your test. Or your doctor may tell you to keep taking it. (These medicines include aspirin and other blood thinners.) Make sure that you understand exactly what your doctor wants you to do.

How is the test done?

  • You may sit in a chair or lie face up on a table. Or you may lie on your stomach on a table that has a hole for your breast to hang through.
  • When the area in your breast is numb, a small cut (incision) is made in the skin.
  • Using imaging, the doctor will guide the needle into the biopsy area.
  • The doctor will take several samples of breast tissue. This may be done with the needle or with a probe that uses a gentle vacuum to remove the samples.
  • A small clip is usually inserted into your breast to mark the biopsy site.
  • The needle is removed and pressure is put on the needle site to stop any bleeding.
  • A bandage is put on the needle site.

How long does the test take?

The test may take 15 minutes to 60 minutes, depending on how the procedure is done.

What happens after the test?

  • You'll be told how long it may take to get your results back.
  • You will probably be able to go home right away.
  • After a specialist looks at the biopsy sample for signs of cancer, your doctor's office will let you know the results.
  • If the test results aren't clear, you may have another biopsy or test.

How can you care for yourself at home?

  • You can go back to your usual activities right away. But avoid heavy lifting for 24 hours.
  • The site may be tender for 2 or 3 days. You may also have some bruising, swelling, or slight bleeding.
    • You can use an ice pack. Put ice or a cold pack on the area for 10 to 20 minutes at a time. Put a thin cloth between the ice and your skin.
    • Ask your doctor if you can take an over-the-counter pain medicine, such as acetaminophen (Tylenol), ibuprofen (Advil, Motrin), or naproxen (Aleve). Be safe with medicines. Read and follow all instructions on the label.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to keep a list of the medicines you take. Ask your doctor when you can expect to have your test results.

Where can you learn more?

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The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.