a method used during a surgical biopsy when the lump is hard to find or when there is an area that looks suspicious on the x-ray. A thin, hollow needle is placed in the tissue and x-rays are taken to guide the needle to the area of concern. A fine wire is put through the center of the needle. A small hook at the end of the wire keeps it in place. The hollow needle is then removed, and the surgeon uses the path of the wire as a guide to find the abnormal area to be removed. See also biopsy.