In a core needle biopsy, the physician makes a small skin incision through which a needle is inserted into the lesion to obtain sample tissue. The hollow spring-loaded device is "fired" repeatedly into the abnormality to collect a sufficient amount of breast tissue for analysis. Usually, 4 to 6 samples are taken (4 to 6 insertions). This biopsy procedure is performed in an outpatient setting or doctor's office without general anesthesia or stitches.