Fine Needle Aspiration of the Thyroid

A fine needle aspiration of the thyroid gland is a procedure to remove thyroid cells for examination. The thyroid is located in front of the trachea (windpipe) at the top of the neck.

Fine needle aspiration of the thyroid is performed by the doctor in the office using ultrasound guidance. Using ultrasound to guide the needle ensures that the sample is taken from the area in question and increases the chances for an adequate sample for interpretation by a pathologist.

How the Test is Performed

This test may be done in the health care provider's office or in a hospital. Usually anesthesia (numbing medicine) is not needed because the needle is very thin.
You will lie on your back with a pillow under your shoulders and your neck extended. After the biopsy site is cleaned, the thin needle is inserted into the thyroid, and a sample of thyroid cells and fluid are removed. The needle is then taken out. This process may be repeated multiple times to ensure adequate sample collection. Pressure will be applied to the biopsy site to stop any bleeding, and the site will be covered with a bandage.

How to Prepare for the Test

Tell your health care provider if you have drug allergies, bleeding problems, or are pregnant. You should also make sure your health care provider has a current list of all medications you take, including herbal remedies and over-the-counter drugs.

How the Test Will Feel

You may feel a sting as the needle is inserted.

Why the Test is Performed

This is a test to diagnose thyroid disease or thyroid cancer.

Normal Results

The thyroid tissue is normal in structure and the cells appear non-cancerous under a microscope.

What Abnormal Results Mean

Abnormal results may mean thyroid cancer, noncancerous tumors, or diffuse thyroid disease such as goiter or thyroiditis.


The main risk is bleeding into or around the thyroid gland. If bleeding is severe, the windpipe (trachea) may be compressed. This complication is rare.