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Breast Needle Localization

This information explains your breast needle localization procedure at Memorial Sloan Kettering (MSK).

Before Your Procedure

  • Do not put anything on your breasts or nipples or under your arms on the day of the procedure. This includes talcum powder, deodorant, and creams.
  • Wear a shirt that buttons in the front and pants. They should be easy to remove and put on after surgery.
  • Follow any additional instructions given to you by your doctor or nurse. 

During Your Procedure

You will have a mammogram of your breast to find the exact area of your abnormal breast tissue or biopsy marker clip. Sometimes the abnormal tissue can’t be seen with a mammogram, so an ultrasound or magnetic resonance imaging (MRI) will be done instead.

Once the abnormal tissue or marker clip is located, your skin will be cleansed and your radiologist will inject a local anesthetic (numbing medication) into the area. Once the area is numb, your radiologist will insert a needle with a thin wire into your breast. An image is taken to confirm that the needle is in the correct position. The needle will then be removed and the wire will remain in your breast.  More mammogram images are taken to confirm that the wire is in the correct position. 

The wire will be covered by a piece of gauze and taped to your skin. Your surgeon will use the wire to find the abnormal breast tissue or biopsy marker during your surgery.

After Your Procedure

After your breast needle localization, you will be escorted from the Breast Imaging Department in Radiology to your next appointment.