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 breast biopsy. The sample of breast tissue will be looked at under a microscope to check for cancer cells.

• A fine-needle aspiration biopsy puts a thin needle through the skin, into the lump, and removes cells to look at. Needle aspiration may be done to see if the lump is solid or fluid-filled ( cyst). If the lump is a cyst, it will go away after the fluid is removed. If there is no fluid, another type of biopsy will be done.
• A core needle biopsy uses a large needle fitted with a special tip. The needle goes through the skin to the lump or area to take out a sample of tissue about the size of a pencil lead.
• A stereotactic biopsy uses a special type of X-ray during a core needle biopsy to find the area of the breast where the biopsy samples will be taken. This technique can check a lump that cannot be felt on breast examination but is seen on mammogram or MRI. A small incision is then made in the skin of the breast, and the core needle is guided by the X-ray to the biopsy site to take tissue samples. Stereotactic biopsy may not be appropriate for all types of breast lumps.
• A vacuum-assisted core biopsy is done with a hollow probe that uses a gentle vacuum to remove a sample of breast tissue. This method may be used for a core needle biopsy or a stereotactic biopsy. Vacuum-assisted biopsy can remove more tissue than a standard core needle biopsy. The single small incision does not require stitches and there is very little scarring.
• An open biopsy makes a cut in the skin and removes a sample of the lump or the entire lump. If your doctor cannot feel a lump, a small wire can be put in the suspicious area during a mammogram or MRI done just before surgery. The wire then guides your doctor to the suspicious area to take a biopsy sample.

More tests or biopsies may be needed if problems are found during the first biopsy or if your doctor is concerned about a certain area of your breast.

Why It Is Done

A breast biopsy checks to see if a breast lump is cancerous (malignant) or noncancerous (benign).

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 aspirin, heparin, warfarin ( Coumadin), enoxaparin sodium ( Lovenox), or clopidogrel bisulfate ( Plavix).
• Are or might be pregnant.