Core Needle Biopsy

During a core needle biopsy, or CNB, a needle is used to remove a small cylinder of from a breast abnormality. The sample of tissue is usually about 1/16 inch in diameter and ½ inch long. The biopsy is conducted with local anesthesia in the provider’s office or clinic. The core biopsy can sample and examine tumors felt by your provider, as well as smaller abnormalities found by ultrasound or other methods.

When performing a core needle biopsy, your provider may use a device known as a Mammotome. During a Mammotome biopsy, also called a vacuum-assisted biopsy, a surgeon inserts a tube larger than those used in a typical core needle biopsy into the breast tissue. The provider then uses suction to draw a cylinder of breast tissue into the tube, and a small rotating knife cuts and removes the tissue for examination. The needle is inserted only once and rotates to get the needed cores. The Mammotome is performed with local anesthesia.

Another tool that can be used during a core needle biopsy is called the advanced breast biopsy instrument, or ABBI. The ABBI uses a rotating circular knife to remove a larger cylinder of tissue for examination. The ABBI procedure removes more tissue than other types of biopsies and are performed using local anesthesia.