A breast biopsy is a common procedure that uses a thin needle to remove a small amount of breast tissue to determine whether cancer is present. At Mass General, only specially trained breast radiologists do these procedures.

During a breast biopsy, the radiologist uses ultrasound, mammography or MRI to guide the needle to the right spot.

Most results of breast biopsies are not cancer. Instead, they can show benign changes in the breast such as fibrous growths, cysts, calcium deposits or old scars.