Core needle biopsy

Core needle biopsy

A core biopsy uses a larger needle to sample breast changes felt by the doctor or
pinpointed by ultrasound or mammogram. (When mammograms taken from different
angles are used to pinpoint the biopsy site, this is known as a stereotactic core needle
biopsy.) In some centers, the biopsy can be guided by an MRI scan.
The needle used in core biopsies is larger than the one used in FNA. It removes a small
cylinder (core) of tissue (about 1/16- to 1/8-inch in diameter and ½-inch long) from a
breast abnormality. Several cores are often removed. The biopsy is done using local
anesthesia (where you are awake but the area is numbed) in an outpatient setting.
Because it removes larger pieces of tissue, a core needle biopsy is more likely than an
FNA to provide a clear diagnosis, although it may still miss some cancers.
Vacuum-assisted biopsies
Vacuum-assisted biopsies can be done with systems such as the Mammotome® or
ATEC® (Automated Tissue Excision and Collection). For these procedures the skin is
numbed and a small incision (about ¼ inch) is made. A hollow probe is inserted through
the incision into the abnormal area of breast tissue. The probe can be guided into place
using x-rays or ultrasound (or MRI in the case of the ATEC system). A cylinder of tissue
is then suctioned in through a hole in the side the probe, and a rotating knife within the
probe cuts the tissue sample from the rest of the breast. Several samples can be taken
from the same incision. Vacuum-assisted biopsies are done as an outpatient procedure.
No stitches are needed, and there is minimal scarring. This method usually removes more
tissue than core biopsies.