Originally published by Harvard Health.
What is the test?
A doctor can do fine needle aspiration in the office by inserting a slender needle into the area of concern and drawing out (aspirating) either fluid from a cyst or a small amount of tissue from a solid mass. Cells from a mass, and sometimes fluid from a cyst, is then sent for microscopic evaluation to determine whether cancer is present. Fine needle aspiration is most commonly used to drain a breast cyst that feels tender or sore. If the cyst is a simple cyst (one that looks clear in an ultrasound exam) and isn’t tender, it doesn’t require aspiration.
How do I prepare for the test?
Tell your doctor if you’re allergic to lidocaine or similar local anesthetics. Otherwise, no preparation is necessary.
What happens when the test is performed?
You wear a hospital gown or undress from the waist up. After examining your breast to feel the lump and cleaning your skin with alcohol and other disinfectants, the doctor may inject a local anesthetic, but even without this numbing medicine, you should feel little pain. Next, he or she gently pinches your breast to hold the lump steady while taking the biopsy. The needle is attached to a syringe, a suction device that “aspirates” or pulls tissue into the needle. To get a good sample, the doctor moves the needle in and out of the lump several times.
In some cases ultrasound will be used to guide the needle.
What risks are there from the test?
You might have a small amount of bruising in the area of the breast that was sampled and some mild soreness afterward.
Must I do anything special after the test is over?
No.
How long is it before the result of the test is known?
Your doctor should have a final report in a few days. If the cells removed during aspiration are not cancerous but the lump feels questionable or appears suspicious on a mammogram or ultrasound, the doctor may recommend further testing with a large core needle biopsy or surgical biopsy.