Breast Cancer: Diagnosis

How is breast cancer diagnosed?

If your healthcare provider thinks you might have breast cancer, you will need certain exams and tests to make sure. Diagnosing breast cancer starts with your healthcare provider asking you questions. They will ask about your health history, your symptoms, risk factors, and family history of disease. Your provider will also give you a physical exam, including an exam of your breasts.

What tests might I need?

You may have one or more of these tests:  

  • Mammogram

  • Ultrasound

  • Breast MRI

  • Biopsy

Imaging tests 

  • Mammogram. A mammogram is an X-ray of the breast. It’s done to look for and learn more about unusual breast changes. These may include a lump, pain, nipple thickening or discharge, or a change in breast size or shape. A screening mammogram is done routinely to check for changes. A diagnostic mammogram might be done if a change is seen on a screening mammogram. It takes more pictures to look more closely at the changes that were seen on the screening mammogram.

  • Ultrasound. This test uses high-frequency sound waves to make images of body tissues on a computer screen. This exam is often used along with a mammogram.

  • Breast MRI. This test uses large magnets and a computer to make detailed images of tissues inside the breast.


A biopsy removes tissue or cells from the breast so they can be tested in a lab. A biopsy is the only way to know if a breast change is cancer.  

A breast biopsy may be done with local or general anesthesia. Local anesthesia means medicine is used to numb the part of the breast where the biopsy will be done. General anesthesia uses medicines to put you into a deep sleep and not feel pain while the biopsy is done.

There are many types of breast biopsy. The type of biopsy you need will depend on the where the lump or change is inside your breast and how big it is.

Types of breast biopsy include:

  • Fine needle aspiration (FNA) biopsy. A very thin needle is put through your skin and into the lump or changed area. A syringe is attached to remove a small sample of fluid and/or cells. This type of biopsy may be used to find out if a breast change is a fluid-filled sac (a cyst) that's usually not cancer or a solid lump.

  • Core needle biopsy. A wider needle is guided through the skin into a lump or other area to remove small cylinders or cores of tissue.

  • Surgical biopsy. This is also called an open biopsy. A surgeon removes part or all of a lump or other area through a cut (incision) in the breast. There are 2 types of surgical biopsy. During an incisional biopsy, a small part of the lump is removed. During an excisional biopsy, the entire lump is removed. If the lump is very small, deep, or both and hard to locate, wire localization may be used during surgery. This is when an X-ray is used to put a thin wire through your skin and into the lump. The surgeon then follows this wire to find the breast lump and take it (and the wire) out.

  • Lymph node biopsy. If lymph nodes under the armpit are swollen or look enlarged on imaging tests, the healthcare provider will want to check them for cancer cells. A needle biopsy may be done to take out and check cells from the lymph node.

Special tools and methods may be used to guide the needles and to help with biopsy procedures. These include:

  • Stereotactic biopsy. This method finds the exact location of a breast change by using a computer and mammogram results to make a 3-D picture of the breast. This picture is used to guide the needle to the right place to take out tissue.

  • Vacuum-assisted biopsy. The surgeon makes a small cut in the skin, and puts a thin, tube into the breast lump or mass. The healthcare provider uses an imaging test to guide the tube to the right place. The breast tissue is gently suctioned into the tube, and a small rotating knife inside the tube removes the tissue.

  • Ultrasound-guided biopsy. This method uses a computer and a small hand-held wand (transducer) that sends out ultrasonic sounds waves to create images of the breast lump or mass. The images are used to guide the needle biopsy.

Getting your test results

When your healthcare provider has the results of your biopsy and other tests, they will contact you. Your healthcare provider will talk with you about other tests you may need if breast cancer is found. Make sure you understand the results and what your next steps should be.

Online Medical Reviewer: Donna Freeborn PhD CNM FNP
Online Medical Reviewer: Jessica Gotwals RN BSN MPH
Online Medical Reviewer: Todd Gersten MD
Date Last Reviewed: 1/1/2023
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