a procedure used to guide a surgical biopsy when the lump is hard to find or when there are areas that look suspicious on the x-ray but there is no distinct lump. X-rays are used to guide the needle to the suspicious area. Then either a small amount of blue dye is injected through the needle, or a thin wire is passed through the needle and left in place, and the needle is removed. The surgeon then uses the dye or the wire as a guide to find the abnormal area to be removed. See also biopsy, wire localization, x-ray.