What Is A Fine Needle Aspiration Biopsy (FNA or FNAB) Of A Thyroid Nodule?

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Every patient has questions when it comes to an invasive procedure. I remember my first FNA. I was very nervous, even though I knew that the doctor had years of experience. It was quick, and I was glad when it was over. It turned out to be very important that I had the procedure done, for the pathologist found cancer cells. But that’s another story. Today we are talking about fine needle aspiration biopsies.


A fine needle aspiration biopsy of a thyroid nodule is a simple and safe procedure performed in the doctor’s office. Typically, the biopsy is performed under ultrasound guidance to ensure accurate placement of the needle within the thyroid nodule. You will be asked to lie down on your back with your head tipped backwards, so that your neck is extended. Sometimes, a pillow is placed under your shoulders to help you get in the best position for the biopsy.


During the procedure you may feel some neck pressure from the ultrasound probe and from the needle. You will be asked to remain as still as possible and avoid coughing, talking and swallowing during the biopsy.


The neck will first be cleaned with an antiseptic. A local or topical anesthetic may be applied. For the biopsy, your doctor will use a very thin needle to withdraw cells from the thyroid nodule. The needle used is smaller in diameter than those used in most blood draws. Your doctor will insert the needle through the skin and into the thyroid nodule. After the sampling, which only takes several seconds, the needle will be removed. New needles are used for additional samples. Several samples of cells will be obtained, by sticking a fine needle in various parts of the nodule usually between two and six times . This assures a better chance to find cancerous cells if they are present. If there is fluid in the nodule, a syringe may be used to drain it.


Once the biopsy is completed, pressure will be applied to the neck. The procedure usually lasts less than 30 minutes.


The procedure is usually performed using a local anesthetic and no medications are used that affect consciousness or thinking. After the procedure, you may be asked to sit up slowly to prevent you from getting lightheaded. Most patients typically leave feeling well. There are very few restrictions on what you can do after a thyroid biopsy. Because of this, it is not generally necessary to bring a companion to help or drive you home.


Some neck discomfort at the site of the biopsy is expected following the procedure. Tylenol® and ice compresses can be used to relieve discomfort.


The biopsy samples may be used to make slides immediately and/or collected in a solution to wash excess blood. Specially trained doctors, cytopathologists, then make slides from the material and examine them under a microscope to make a diagnosis. Generally, it can take anywhere from a few days to two (2) weeks for the result to return.


Since my fellowship and going into private practice, I have done hundreds of FNAs. I am one of the few physicians in the low country to earn ECNU certification status, a professional certification in the field of neck ultrasonography for physicians who perform consultations and diagnostic evaluations for thyroid and parathyroid disorders through both diagnostic ultrasound and ultrasound-guided fine needle aspiration. If you are having thyroid or parathyroid issues, please make an appointment with us at Palmetto Endocrinology today.

Joseph W. Mathews, MD, FACP, FACE, ECNU, CCD Joseph Mathews, MD, FACP, FACE, ECNU, CCD Joseph W. Mathews M.D., a board certified Endocrinologist and Medical Director of Palmetto Endocrinology, was born and raised in South Carolina. He earned his Bachelor of Science in Biology from the College of Charleston, Cum Laude. He then achieved his M.D. at the Medical University of South Carolina where he also completed his residency in Internal Medicine and a Fellowship in Endocrinology, Diabetes, and Metabolism. Dr. Mathews is also a Fellow of both the American College of Endocrinology and the American College of Physicians, holds an Endocrine Certification in Neck Ultrasound (ECNU) and is a Certified Clinical Densitometrist (CCD). He has extensive experience performing ultrasound guided fine needle aspiration biopsies. His practice includes a range of specializations including prescribing and fitting patients with insulin pumps. Dr. Mathews' practice has drawn patients from out of state to benefit from his expertise in thyroid disorders, diabetes, cortisol problems and their Endocrine disorders.

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