FNA biopsy uses a very small needle to obtain a specimen, therefore, the technique is usually free of significant complications and offers much less risk to patients than many other biopsy procedures. The most common complication is slight bruising or tenderness of the area for a few days following the procedure. Discomfort should be relieved by an over-the-counter pain reliever such as Tylenol or the application of an ice pack for short periods following your return home. ***If you experience swelling that does not go away, signs of infection, continued bleeding, a fever over 100 degrees F, or if you experience pain that is not relieved by Tylenol or other non-aspirin products, call your doctor's office immediately.***