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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 be sure. Diagnosing breast cancer starts with your healthcare provider asking you questions. He or she will ask you about your health history, your symptoms, risk factors, and family history of disease. Your healthcare 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 the following tests:  

  • Mammogram

  • Ultrasound

  • Breast MRI

  • Biopsy

  • Nipple discharge exam

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 checks for changes. A diagnostic mammogram uses more pictures to look more closely at changes that were seen on a 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 magnetic resonance imaging (MRI). This test uses large magnets and a computer to make detailed images of tissues in the breast.


A biopsy removes tissue or cells from the breast to check under a microscope. A biopsy is the only way to know if cells are cancer.  

A breast biopsy may be done with local or general anesthesia. Local anesthesia uses medicine to numb the area of the breast where a needle will be inserted. General anesthesia uses medicines to put you into a deep sleep while the biopsy is done. There are several types of breast biopsy. The type of biopsy done will depend on the location and size of the breast lump or change.

Types of breast biopsy include: 

  • Fine needle aspiration biopsy. A very thin needle is placed into the lump or other area to remove a small sample of fluid or tissue. A fine needle aspiration biopsy may be used to help find out if a breast change is a cyst (a fluid-filled sac that's usually not cancer) or a solid lump.

  • Core needle biopsy. A large needle is guided into a lump or other area to remove small cylinders of tissue (cores). No incision is needed.

  • Surgical biopsy. This is also called an open biopsy. A surgeon removes part or all of a lump or other area through an incision into 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 and deep and hard to locate, the wire localization method may be used during surgery. A wire is placed into the lump under X-ray guidance. The surgeon then follows this wire to help locate the breast lump.

  • Lymph node biopsy. If lymph nodes under the armpit are swollen or look enlarged on imaging tests, the doctor 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 assist with biopsy procedures. These include:

  • Stereotactic biopsy. This method finds the exact location of a breast lump or area by using a computer and mammogram results to create a three-dimensional (3D) picture of the breast. A sample of tissue is removed with a needle.

  • Mammotome breast biopsy system or ATEC (Automated Tissue Excision and Collection). This is also called vacuum-assisted biopsy. A type of thin, hollow tube is inserted into the breast lump or mass. 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 transducer that sends out ultrasonic sounds waves to create images of the breast lump or mass. The images help to guide the needle biopsy.

Nipple discharge exam

Fluid may be collected from nipple discharge and then sent to the lab to look for cancer cells. Most nipple secretions are not cancer. An injury, infection, or benign (non-cancerous) tumor may cause discharge.

Getting your test results

When your healthcare provider has the results of your biopsy and other tests, he or she will contact you with the results. Your provider will talk with you about other tests you may need if breast cancer is found. Make sure you understand the results and what follow-up you need.