A Fine Needle Aspiration (FNA) biopsy uses a small needle to remove fluid or cells from a suspicious lesion. These cells are then smeared onto slides which get sent to pathology for examination. This procedure is done in the doctor’s office or imaging center while the patient is awake. At the Pink Lotus Breast Center, for example, an FNA is performed in the office by a surgeon or radiologist.
How does it work?
Generally, no local anesthetic or numbing medicine is used because the burning from the local anesthetic hurts more than the quick poke of the small needle (really, it does!). A small needle attached to a syringe is quickly inserted through your skin into the area of suspicion, the syringe is put on suction, and cells are removed.
If the lesion can only be seen with ultrasound, then the biopsy will be performed under ultrasound guidance, so that your doctor can be precise and watch the needle enter the target tissue. The entire procedure takes only about 30 seconds. A band aid is placed at the insertion site, you will not have a scar, and you can drive and return to work immediately after the biopsy.
While FNA is the easiest type of biopsy, it does have two main disadvantages. First, an FNA is only 90-95% accurate because it removes individual cells and not a continuous piece of the suspicious area. In other words, the sample can be too sparse to make a definitive diagnosis, and if this happens, either a core needle biopsy or an excisional biopsy will likely be needed. Second, if cancer cells are identified on an FNA, you cannot tell the subtype of cancer (e.g., in situ vs. invasive), and special cancer studies cannot be done on such a tiny sample (like testing for estrogen receptors). This information is eventually obtained when a larger biopsy is performed, so it is not a lasting concern.