What is a breast biopsy?

A breast biopsy is a procedure that removes a sample of breast tissue so that a pathologist (a type of doctor) can look at it under a microscope for signs of disease and cancer.

There are three different ways to do a breast biopsy.

• A fine needle aspiration biopsy uses a very thin needle to remove a sample of breast cells or fluid.
• A core needle biopsy uses a larger needle and sometimes a vacuum probe to remove a sample. This sample is about the size of a grain of rice.
• A surgical biopsy is surgery to remove a sample of tissue (an incisional biopsy). In certain cases, the entire tumor will be removed (an excisional biopsy).

Your health care provider will decide which of these biopsy types is best for you depending on the results of a recent clinical breast exam or mammogram (an x-ray picture of the breast).

Other names: core needle biopsy; core biopsy, breast; fine-needle aspiration; open surgery biopsy

What is it used for?

A breast biopsy is the only way to find out whether a suspicious change in your breast is cancer. Breast cancer is cancer that forms in the milk ducts (tubes that carry milk to the nipple) and the lobules (the small lobes of breast tissue that make milk). Breast cancer is much more common in women, but men can get it, too.

Why do I need a breast biopsy?

You may need a breast biopsy if:

• You or your provider felt a lump, thickening, or other change in your breast.
• A mammogram, ultrasound, or MRI test shows a lump, calcium deposits, or other signs that might mean cancer.
• The skin on your breast or nipple is red, scaly, or swollen, or your nipple is pulled inward.
• You have a discharge of abnormal fluid coming from your nipple.

If your provider suggests that you have a breast biopsy, it doesn't mean you have breast cancer. Most breast lumps and other changes that are checked with biopsies turn out to be benign, which means they are not cancer.

What happens during a breast biopsy?

Biopsies are often done using mammography, ultrasound, MRI, or x-rays to help see exactly where to take the tissue sample. Your procedure will vary depending on which method is used to guide the biopsy, but the general steps are usually the same.

For a fine needle aspiration biopsy or a core needle biopsy:

• Your provider will clean the skin on your breast and give you a shot of medicine to numb the area, so you won't feel any pain. The shot may sting briefly.
• You may be sitting or lying down. If images are used to guide the biopsy, you may lie on your side, back, or belly with your breast in an opening on the table.
• For a fine needle aspiration biopsy, your provider will insert the needle into the biopsy site and remove a sample of cells or fluid. For a core biopsy, a tiny cut may be made to insert a wide needle or a vacuum device. You may feel a little pressure when the sample or samples are removed.
• Pressure will be applied to the area until the bleeding stops.
• Your provider will cover the biopsy site with a sterile bandage. If you had a small incision, small strips of medical tape may be used to close the wound.

For a surgical biopsy:

• You'll lie on an operating table.
• The skin over the biopsy area will be cleaned.
• Your provider will give you medicine to make sure you don't feel any pain during the procedure. They may give you a single injection (shot) to numb your breast. Or they may give you general anesthesia, which is medicine given through an IV (intravenous line) in your arm or hand to make you sleep.
• When you are numb or asleep, the surgeon will make a small cut in your breast tissue to remove part or all of the lump. In certain cases, tissue around the lump may also be removed. This may help avoid the need for more surgery if cancer cells are found in the lump.
• The cut in your skin will be closed with small strips of medical tape or stitches and covered with a sterile bandage.

If you're getting a surgical biopsy, your provider may also perform a wire localization procedure to guide them to the lump. They will insert the wire either the day before or the day of the biopsy. To do this, your provider will clean the skin on your breast and give you a shot of medicine to numb the area. Then they will:

• Place a thin, hollow needle into the biopsy area.
• Insert a sterile wire through the center of the needle.
• Remove the needle, leaving the wire in your breast until the biopsy is done. Once the biopsy is done, your provider will remove the wire.

The type of biopsy you have will depend on:

• The size and location of the suspicious tissue in your breast.
• How many areas of your breast are involved.
• How abnormal the tissue looks on a mammogram or other image.
• Your general health and preferences.

Ask your provider about why you need a biopsy and which type is right for you.

Will I need to do anything to prepare for the test?

You may need to stop taking certain medicines, such as blood thinners like aspirin, before this test, so tell your provider about all the medicines and supplements you take. Don't stop or start taking anything unless your provider tells you to.

Before you get any procedure, you should tell your provider about any recent surgeries or known allergies. You should also tell them if you're pregnant.

If you're having general anesthesia, you will probably need to fast (not eat or drink) for several hours before surgery. If you have general anesthesia or medicine to relax, you may be groggy after the procedure, so plan to have someone take you home.

Are there any risks to the test?

It's common to have some bruising and temporary discomfort after a breast biopsy. Possible risks include:

• Infection, which can be treated with antibiotics
• Bleeding at the biopsy site

Your provider will give you instructions on how to care for the biopsy area and manage any discomfort. If you're having general anesthesia, talk with your provider about how it may affect you.

What do the results mean?

It may take several days to a week to get your biopsy results (often called a pathology report). The report is written for your provider and will include a lot of medical terms. But the most important part of your report will be the diagnosis, which will be one of these categories:

• Normal. No cancer or abnormal cells were found.
• Abnormal breast changes that aren't cancer and don't increase your risk for breast cancer. Some of these conditions often get better on their own, while others may need treatment.
• Abnormal breast changes that increase your risk for breast cancer. These cells are not cancer, but if you have them, you are more likely to develop cancer. You may need a surgical biopsy to remove any additional abnormal tissue. In addition, your provider may refer you to a doctor who specializes in breast cancer.
• Breast cancer. If your provider finds cancer cells, your report will include details about how fast the cancer cells are growing, how much they look like normal cells, and other information to help plan the most effective treatment. Usually, a doctor who specializes in breast cancer will provide your care.

Your test results may also tell you about your tumor type and grade and whether or not you have certain hormones or proteins that make you more likely to develop cancer. Ask your provider to explain any additional information in your report.

Learn more about laboratory tests, reference ranges, and understanding results.