Test Overview

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.

• 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.