Physical exams, mammograms and other imaging studies can help detect a lump or other abnormality in the breast. But the answer to the real question of whether or not the suspicious area is benign or cancerous can only be determined by performing a breast biopsy. This procedure involves removing some cells from the abnormal area and then examining them under a microscope to make a diagnosis.

Stereotactic breast biopsy uses mammography to help locate the abnormality and guide the physician’s instruments to the site that requires additional testing. The procedure may be recommended after a mammogram shows a suspicious solid mass, microcalcifications (tiny cluster of calcium deposits), the structure of the breast tissue is distorted, a spot of abnormal tissue change, or a new mass or area of calcium deposits at a prior surgery site. The mass or abnormality that is being examined during a biopsy is not taken out during the procedure. Rather, only a sample of cells is removed. Further treatment or surgery will be determined based on results of the biopsy.

Stereotactic mammography helps identify the exact location of the breast mass using a computer and X-rays taken from two different angles. With these coordinates, the physician is able to insert a needle in the proper location, advance it to the mass, and then remove tissue samples. The procedure can be performed using a core needle, which is a hollow needle that allows one sample of breast tissue to be removed per insertion, or a vacuum-assisted device, which uses pressure to pull tissue into the needle.

During the biopsy, the patient is typically asked to lie facing down on a special table that allows the breast to be biopsied to hang down through an opening. The table is raised and the physician performs the biopsy from underneath. After the breast is cleaned a numbing medicine is injected. The breast is then pressed down into position and stereotactic X-ray images are taken.

A tiny incision is made where the biopsy needle is to be inserted. The needle is advanced to the abnormality using the X-rays and computer-generated coordinates. More images are done to make sure the needle is in the right place. After taking three to 10 tissues samples, the needle is removed and a small marker may be placed at the incision site so it can be located later if necessary.

Pressure is applied to the incision site after the biopsy to stop any bleeding. No stitches are necessary. The entire procedure takes about one hour and is usually performed on an out-patient basis. Patients are awake during the biopsy and should experience little or no discomfort. The breast may be sore and tender for several days. Patients should avoid heavy lifting or work for a day after returning home, but can then resume normal activities. For more information about stereotactic breast biopsy, talk with your doctor or visit the patient information website co-sponsored by the American College of Radiology and Radiologic Society of North America at www.radiologyinfo.org.