What happens during a biopsy?

A biopsy is an outpatient procedure to remove a tissue sample from the breast under local anaesthesia. Similar to drawing blood, a thin hollow needle is inserted through the skin into the abnormal area in the breast. Little cylinders of tissue are then removed by the needle. This so-called trephine biopsy or vacuum biopsy is a minor procedure with usually no complications. A pathologist then looks at the tissue removed from the breast under a microscope.