Needle Biopsy: Thyroid
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Needle Biopsy: Thyroid

(Fine-Needle Aspiration; Skinny-Needle Biopsy; Coarse-Needle Biopsy)

En Español (Spanish Version)


A needle biopsy of the thyroid refers to using a needle to remove a small sample of tissue from your thyroid gland. The test is usually done when a lump, called a nodule, is found in the thyroid.

Nodules occur when thyroid cells grow together and form lumps in the thyroid. Nodules are very common and usually do not require treatment. However, between 5% to 10% of nodules are cancerous.

Thyroid Nodule

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Parts of the Body Involved

The thyroid gland is made up of two roundish lobes, which are connected by a middle part. It is about two inches across and is shaped somewhat like a butterfly.

The thyroid controls many body functions, including heartbeat, blood pressure, and body temperature. It is also responsible for childhood growth and metabolism. Metabolism refers to how your body turns food into energy.

Reasons for Procedure

A biopsy is usually done to test if a nodule contains benign or malignant cells. It may also be ordered if the thyroid is enlarged even if there is no nodule present, especially in individuals over 50 years old. Although usually not cancerous, all nodules should be checked by a physician to determine their condition.

A biopsy is the only test that can confirm whether cancer is present. There are two types of biopsies:

  • Fine-needle aspiration (FNA), the most common type
  • Coarse-needle biopsy (CNB)

Risk Factors for Complications During the Procedure

If you have a bleeding disorder, you should discuss options with your doctor.

What to Expect

Prior to Procedure

There is no special preparation for either type of biopsy. However, you should tell your doctor:

  • If you have any allergies
  • What medications you are taking; you may be advised to avoid drugs like aspirin, ibuprofen, and coumadin, that could increase your chances of bleeding or bruising
  • If you could be pregnant

For coarse-needle biopsy, your doctor may order some tests to determine how well your blood clots.


If you are having a FNA, an anesthetic is not usually given.

For a CNB, a mild sedative may be given one hour before the procedure to help you relax. A local anesthetic is injected at the beginning of the procedure to numb the site of the biopsy.

Description of the Procedure

You will be asked to lie on your back. A pillow will be placed under your shoulders, and your neck will be extended. The site of the biopsy will be cleansed with an antiseptic solution.

For a FNA, your doctor will insert a tiny hollow needle into the nodule to collect a sample of tissue. For a CNB, after injecting local anesthetic, your doctor will make a small incision, about one inch, into your skin. The biopsy needle will be inserted through the incision and into the thyroid to collect a sample of tissue.

The process of collecting tissue samples may be repeated several times in different parts of the nodule. This increases the chance of finding abnormal cells, if there are any.

After Procedure

You will apply pressure to the site to stop any bleeding, and a bandage will be applied. The biopsy is sent to the lab for examination.

How Long Will It Take?

10 to 30 minutes, plus 30 minutes afterward for observation

Will It Hurt ?

After a FNA, you should not have any pain or tenderness where the needle went in.

For a CNB, when the anesthesia is injected, it may cause a stinging feeling. You may feel soreness at the site of the biopsy for one or two days after the test.

Possible Complications

There are no complications associated with the FNA.

A CNB may cause bleeding into the thyroid gland.

Average Hospital Stay

This procedure is usually done in the doctor’s office, but may also be done as an outpatient procedure at the hospital.

Postoperative Care

Thirty minutes after the procedure, you may return home or to work without any negative effects. Other post-procedure suggestions are to:

  • Remove the bandage after a few hours for the FNA, and after a few days for the CNB;
  • Avoid vigorous physical activity for 24 hours; and
  • Take acetaminophen (Tylenol) for any discomfort.


If the thyroid cells have normal appearance and makeup, then there is no indication of cancer. Abnormal results can indicate the following causes:


If cancer is found in the biopsy results, the condition should be addressed by an experienced thyroid surgeon. Thyroid cancer is usually curable. Any potentially cancerous nodule that is not removed should be examined every 6 to 12 months.

Call Your Doctor If Any of the Following Occurs

Contact your doctor if you experience any of the following:

  • Bleeding
  • Fever
  • Trouble breathing
  • Excessive neck swelling
  • Unusual pain or discomfort


The American Thyroid Association, Inc.

The Thyroid Foundation of America, Inc.


BC Health Guide, British Columbia Ministry of Health

The Thyroid Foundation of Canada


Beers, MH, Fletcher AJ, Jones TV, et al. The Merck Manual of Medical Information: Second Home Edition . Whitehouse Station, NJ: Merck Research Laboratories; 2003.

Ross, DS. Fine needle aspiration biopsy of thyroid nodules/instructions for patients undergoing core needle biopsy. Thyroid Foundation of Canada website. Available at: . Accessed August 24, 2005.

Suen KC. Fine needle aspiration biopsy of the thyroid. Canadian Med Assoc J . 2002; 167:491-95.

Thyroid biopsy. Dr. Joseph F. Smith Medical Library website. Available at: . Accessed August 24, 2005.

Thyroid nodule. Dynamed website. Available at: . Accessed August 24, 2005.

Thyroid nodule fine needle aspirate. Medline Plus, National Library of Medicine and the National Institutes of Health website. Available at: . Accessed August 24, 2005.

Thyroid nodules. New York Thyroid Center website. Available at: . Accessed August 24, 2005.

Thyroid nodules: symptoms, causes, diagnosis, treatment. American Thyroid Foundation website. Available at: . Accessed August 24, 2005.

Last reviewed January 2008 by Ronald Nath, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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