A stereotactic biopsy is done to evaluate a lump that
cannot be felt on breast examination but is seen on mammogram or
ultrasound. It is done using a special type of X-ray instrument
that can precisely locate the area of the breast from which the
biopsy sample is to be taken. A small incision is then made in the
skin of the breast and a needle is guided by the instrument to the
exact biopsy site to collect a tissue sample. Stereotactic biopsy
may not be appropriate for all types of breast lumps.
An ultrasound biopsy is a test that uses reflected
sound waves to produce an image of organs and other structures in
the body. It does not use X-rays or other types of possibly harmful
radiation.