Fine Needle Aspiration (FNA) is a simple and easy procedure. Your doctor has sent you to Torrance Memorial Medical Center to obtain a sample of cells from a nodule for diagnosis.
Rest assured that FNA using ultrasound guidance is a very common and routine procedure done at Torrance Memorial Medical Center. Our radiologists are highly skilled at performing FNA with ease and efficiency.
There is no patient preparation for an FNA, although it is helpful if you can be calm and relaxed during the procedure.
Benefits of Using Ultrasound
Ultrasound is very helpful in performing FNA safely. On the day of your scheduled FNA procedure, an ultrasound technologist will perform an ultrasound of the nodule that your doctor wants sampled. This will give the radiologist (doctor specializing in ultrasound) an opportunity to see the nodule before the FNA is done. The radiologist will then determine the safest route to obtain the FNA sample.
How FNA is Performed?
After the radiologist reviews the ultrasound images, the ultrasound technologist will set up the necessary equipment needed to perform the FNA.
The radiologist will clean your skin in the area the needle is to be placed to obtain the sample. While watching the ultrasound screen, the radiologist can see the small needle as it enters the nodule. The needle will be moved in and out of the nodule for approximately three to ten seconds to obtain cells. This sample will then be placed on glass slides. This procedure will be repeated two to three times to increase the likelihood of a good diagnostic sample. Depending on the nature of the nodule, the sample may be placed into several different types of collection medium. All material obtained is then evaluated by a pathologist at Torrance Memorial Medical Center.
Possibility of Obtaining a Non-Diagnostic Sample
Results from this procedure are typically available to your physician within seven days. FNA results can be "non-diagnostic" up to 20% of the time. The needles used are very small and obtain cells, not pieces of tissue. Some types of nodules can't be accurately diagnosed by analyzing only cells. Sometimes the number of cells obtained is insufficient for diagnosis. Nodules that contain fluid or blood are particularly prone to non-diagnostic FNA. Your doctor may want a non-diagnostic FNA repeated at a later date, although even a repeat FNA may be non-diagnostic. Alternatively, a repeat biopsy with a slightly larger needle (core biopsy) may be recommended for more optimal sampling of the nodule.
Will I Feel Pain?
Most patients tolerate FNA very well. Many report feeling a mild to moderate pinching sensation. The needle used for FNA is tiny and smaller than the needle used when taking routine lab blood tests. Therefore, no anesthetic is needed.
What Else Should I Know?
To help the procedure go as smoothly as possible, please cooperate with the following: Do not talk or swallow during the procedure. Most nodules located in the neck area will move during talking or swallowing. Do not move during the procedure. Once the radiologist has positioned you for the easiest access to the nodule, it is important that you remain in that position until samples are obtained.
In the Event that the Procedure is Not Done
There may be cases in which the radiologist decides not to perform FNA. These are examples of why:
- The size of the nodule. When the ultrasound indicates a nodule smaller than one centimeter in size.
- Location of nodule. If there is no safe path to obtain a sample of the nodule.
- Nodule is not seen. When the nodule is not visualized easily using ultrasound.
- Composition of nodule. Nodules that are predominantly fluid filled are not typically aspirated.