Core Needle Biopsy Core Needle Biopsy is done with a larger needle, which can yield a larger sample. This type of biopsy generally requires a way to pinpoint the location of the tumor. It can be done using ultrasound equipment, or special stereotactic mammography equipment. The procedure takes only a few minutes. Most women who have had the procedure report little or no discomfort.
Stereotactic guidance is the most common technique for performing a core needle biopsy.
Using special mammography equipment, a radiologist will take two pictures of the breast, at angles to each other. These pictures will be analyzed by a computer to pinpoint the location of the tumor. Using the guides built into the machine, the radiologist will then be able to place the needle precisely into the tumor, even if it is as small as a pea. The core biopsy itself is performed with a device that works like an ear-piercing instrument, and propels a needle very rapidly through the lesion. A special notch in the needle traps a sliver of tissue for examination.