How Breast Cancer Is Diagnosed

If breast cancer is suspected, imaging tests and a biopsy may be needed.

Breast cancer is often found during a screening mammogram or breast exam, but sometimes a woman notices and reports a change in her breast. If you have a suspicious lump or an abnormal screening result, you will need to have follow-up tests.

 

Imaging tests are usually the first step. One or more of these tests may be done:

  • Diagnostic mammography. A mammogram is basically an x-ray of the breast.For screening mammograms, two pictures are taken of each breast. When mammography is used for diagnosis, pictures are taken from different angles, focusing on the area where an abnormality was found.If any questions remain, an ultrasound or MRI may be done next.
  • Breast ultrasound. An ultrasound uses sound waves to create images of the breast tissue that can be viewed on a screen. An ultrasound can show if a lump is solid or fluid-filled (a cyst). Cysts are rarely cancer.
  • MRI of the breast. MRI uses radio waves and magnets to create hundreds of detailed images of the breast tissue.It can sometimes help a doctor find a breast lump that can be felt but can't be seen with mammography or ultrasound.

If your doctor still has any concerns, you will need to have a biopsy. For this procedure, a doctor removes a sample of the suspicious breast tissue so it can be checked for cancer cells. A biopsy is the only sure way to know if a breast lump is cancer.

It's normal to be worried if you have been told you need a biopsy. But it's important to remember that four out of five women who get breast biopsies do not have cancer. Many other conditions can cause suspicious lumps, and a biopsy can help identify those.

There are different types of biopsy. Your doctor will decide which type is best based on the nature and location of the lump and your overall health.

Biopsy methods include:

  • Fine needle aspiration. The doctor uses a very thin needle to remove either fluid from a cyst or tissue from a solid mass. Ultrasound may be used to help the doctor see where to place the needle. If the results are not clear, another type of biopsy will be done.
  • Core needle biopsy. The doctor uses a slightly larger needle to remove a few core samples of the abnormal tissue.
  • Stereotactic core needle biopsy. For this procedure, your breast is compressed (similar to a mammogram), and x-rays and a computer are used to spot the exact locations to insert the needle.
  • Surgical biopsy. This is surgery to remove the tissue for biopsy.In an incisional biopsy, the surgeon takes part of the abnormal tissue. In an excisional biopsy, the entire suspicious area is removed, as well as a small margin of normal tissue. This procedure is usually done in the outpatient section of a hospital. Local anesthesia is used to numb the breast. You may also be given a medication to help you relax and make you drowsy.

After the biopsy is done, the sample is sent to a pathologist. This doctor will examine the tissue or fluid under a microscope to look for abnormal cell shapes and growth patterns. The pathologist will send a report of the findings to your doctor.

If cancer is found, the report will include the type of cancer and how aggressive it is. Your doctor will use this information to suggest the best treatments.