Core needle biopsy is the procedure to remove a small amount of suspicious tissue from the lesion with a larger “core” (meaning “hollow”) needle. It is usually performed with a local anesthesia, meaning that the anesthetized lesion is numbed. The radiologist or surgeon performing the core-needle biopsy may use specialized imaging equipment such as ultrasound to guide the needle to the desired site. The procedure is conducted to sample abnormal soft tissue mass tissue, which is then examined to detect the presence of abnormalities
A core needle biopsy is generally performed to follow up on an abnormality seen on a scan or found by physical exam. It is performed as an outpatient procedure, under local anesthesia using a numbing medicine, without the need for general anesthesia.
Unlike FNA, a core needle biopsy uses a slightly larger needle, similar to the needle used in drawing blood. This needle has a hollow middle, which can collect cells in their natural state, with surrounding cells attached. After cleansing the skin, a small intradermal weal of local anaesthetic (lidocaine) is raised at the biopsy site The needle is passed through the mass after the area is numbed with a local anesthetic.
However, excessive infiltration is to be avoided as it will obscure the position of the underlying mass.
The closed needle held in a spring-loaded gun is inserted until it reaches the lesion.
While holding an ultreasound probe with one hand, the second hand maniuplates the gun to be located at the target position to fire.
After the gun is released and the tissue is collected, the sample is placed onto a glass slide for a pathologist to examine. After the pathologist has established a diagnosis, a examination report will be generated for further treatments.
The actual insertion of the needle is generally less than one minute. Again, it may be inserted several times to obtain enough of a sample. The whole procedure can take 15-30 minutes.
The most important risk associated with a core needle biopsy is bleeding. Generally, there is very little bleeding associated with the procedure, although rarely, a hematoma, or a pocket of blood, will collect at the site of the biopsy. This can be slightly uncomfortable but should resolve over the next few days. If there is severe pain following the procedure, immediately contact the doctor.