Women's Health

A breast biopsy removes a sample of breast tissue that is looked at under a microscope to check for breast cancer. A breast biopsy is usually done to check a lump found during a breast examination or a suspicious area found on a mammogram, ultrasound, or magnetic resonance imaging (MRI). See a picture of the female breast.

There are several ways to do a breastbiopsy. The sample of breast tissue will be looked at under a microscope to check for cancer cells.

• Fine-needle aspiration biopsy. Your doctor inserts a thin needle into a lump and removes a sample of cells or fluid.
• Core needle biopsy. Your doctor inserts a needle with a special tip and removes a sample of breast tissue about the size of a grain of rice.
• Vacuum-assisted core biopsy. This is done with a probe that uses a gentle vacuum to remove a small sample of breast tissue. The single small cut doesn't require stitches and leaves a very small scar.
• Open (surgical) biopsy. Your doctor will make a small cut in the skin and breast tissue to remove part or all of a lump. This may be done as a first step to check a lump or if a needle biopsy doesn't provide enough information.

If needed, your doctor may use ultrasound or MRI to guide the biopsy needle. Or your doctor may use a computer to locate the exact spot for the biopsy sample from mammograms that have been taken from two angles (stereotactic needle biopsy). A fine wire, clip, or marker also may be used to mark the site.

Why It Is Done

A breast biopsy checks to see if a breast lump or a suspicious area seen on a mammogram is cancerous (malignant) or noncancerous (benign). Testing a biopsy sample is the only reliable way to find out if cancer cells are present.¹

How To Prepare

Tell your doctor if you:

• Are taking any medicines.
• Are allergic to any medicines, including anesthetics.
• Are allergic to latex.
• Have any bleeding problems or take blood thinners, such as warfarin (Coumadin) or clopidogrel (Plavix).
• Are or might be pregnant.

You will be asked to sign a consent form. Talk to your doctor about any concerns you have regarding the need for the biopsy, its risks, how it will be done, or what the results will mean. To help you understand the importance of the biopsy, fill out the medical test information form(What is a PDF document?).

If you take a blood thinner, you will probably need to stop taking it for a week before the biopsy.

If a breast biopsy is to be done under local anesthesia, you do not need to do anything else to prepare for the biopsy.