Stereotactic breast biopsy uses computerized X-rays to precisely locate an area within the breast from which tissue samples need to be taken. This procedure is especially useful when a doctor can see calcifications or a mass in the breast on a mammogram but cannot locate it by touch.

Based on mammograms taken from two angles, computerized equipment maps the precise location of the mass or calcifications. A small incision is then made in the skin of the breast. The instrument is used to guide a needle to the exact site to collect tissue samples for biopsy. Samples of breast tissue are removed and then examined under a microscope for signs of cancer.

Stereotactic biopsy may not be recommended for all types of breast lumps.