Thyroid Fine Needle Aspiration Biopsy (FNAC)

by | Oct 10, 2023

If you’ve been told you need a thyroid biopsy, this can be intimidating. However, if you have thyroid nodules, one option is thyroid fine needle aspiration biopsy (FNAC). This is a safe and simple procedure performed under ultrasound guidance and placing a very fine needle within the thyroid nodule. 

Doctor checking thyroid of female patient

What is the Thyroid Gland?

The thyroid gland is located at the base of your neck. It is a butterfly shaped gland just below the voice box and produces two key hormones, trilodothyronine (T3) and thyroxine (T4). These hormones are needed by every cell in your body. T4 is typically converted to T3 in other cells.

These hormones regulate the metabolism of your cells, meaning that if you have too much of them your cells work faster than normal and too little means everything slows down.

When and Why You Should Go For FNAC

Fine needle aspiration cytology (FNAC) is recommended if you have nodules in your thyroid to determine whether they are cancerous or not. Thyroid nodules are abnormal growths of cells that form within your thyroid gland, creating a lump. The vast majority of these nodules (over 90%) are benign, but they need to be investigated as thyroid cancer is more treatable in the early stages.

Biopsy is, thus, a way to detect cancer, and potentially help treatment. Thyroid nodules can also be caused by Hashimoto’s thyroiditis, a common cause of hypothyroidism, or iodine deficiency.


How is FNAC Performed

FNAC is a simple procedure and performed with only local anesthetic.

Your neck will be cleaned with an antiseptic solution and a local anesthetic applied. Ultrasound gel will be used to obtain images that guide the doctor to the nodule. The doctor will insert a very fine thin needle, even smaller than ones used for blood draws, into the nodule to draw out cells. The sampling takes only a few seconds and two to six samples are normally taken. Pressure will then be applied to prevent bleeding.

What to Expect During FNAC

Before the Procedure

If you have extreme anxiety about needles, talk to our clinic, as there are options that can help you get through the procedure, such as listening to music for distraction or, if all else fails, taking an anti-anxiety medication. (This will require somebody to drive you home after the procedure).

Wearing clothing with a high collar or any jewelry around your neck isn’t advised.

During the Procedure

As mentioned, a thyroid nodule specialist will clean your neck and apply topical anesthetic and the ultrasound gel. The actual sampling takes only a few seconds per samples. You will typically be in the room within under half an hour.

After the Procedure

For most people, only local anesthetic is used. There is no need to be on any medications that affect your ability to think (unless anti-anxiety medications are requested specifically for certain patients). Some people may experience lightheadedness when they sit or stand after the procedure and these activities should be done carefully.

It is possible to drive home on your own and return to work the following day. The biopsy material is sent to the lab for testing. 

The Thyroid Gland Function and Common Disorders

The thyroid gland may be a small organ, but it is crucial to our overall health and well-being. Learn more about the function of the thyroid gland, risk factors, and early warning signs of problems.

The Results and Side Effects of Thyroid Biopsy

The only common side effect is mild pain at the biopsy site for a few days, which can be managed with ice and over-the-counter NSAIDs and panadol.

You will get your results in anywhere from a few days to two weeks, and the possible results are:

  • Benign. Benign nodules are monitored with either ultrasound followups and radiofrequency ablation.
  • Malignant. Only 3 to 7% of nodules come back malignant. The first line treatment is surgery.
  • Suspicious for malignancy. This means there’s a high chance of cancer, sufficient that surgery is likely recommended.
  • Indeterminate. This means that they aren’t sure, and you will likely need a followup biopsy or genetic testing.
  • Non-diagnostic. This means not enough cells were drawn and you will need another biopsy. This doesn’t happen very often.


Access Expert Care and World-Class Thyroid Nodule Treatment in Singapore 

In conclusion, while the vast majority of thyroid nodules are noncancerous, a biopsy is the only way to determine whether they are, or are likely to turn into, cancer. FNAC is a less invasive, easy way to perform a thyroid biopsy.

If you have thyroid nodules, reach out to arrange an appointment to discuss FNAC. At Supreme Vascular and Interventional Clinic, we understand how accurate diagnosis and expert treatment for thyroid conditions matter. If you’re facing concerns or symptoms related to your thyroid health, take the first step towards peace of mind. Our thyroid nodule specialist, Dr. Manish Taneja, will guide you through the thyroid fine needle aspiration biopsy process. 

Thyroid Nodule Radiofrequency Ablation (RFA) Treatment

Radiofrequency ablation aims to give patients a non-surgical option for treating thyroid nodules. This procedure is a minimally invasive option that a surgeon can perform, should the preliminary tests determine that you would benefit from it.

The Advantages of RFA of Thyroid Nodules

The major advantages of the technique are as below.

  1. It is done as day surgery procedure under light sedation.
  2. It takes about 45 minutes to one hour to complete the entire procedure.
  3. Patients are discharged the same day.
  4. Normal thyroid tissue adjacent to the nodule is preserved.
  5. It does not affect thyroid function.
  6. Multiple nodules can be treated at same time.
  7. The treated nodules do not regrow again.
  8. No surgical scar with needle mark on the skin.
  9. Quick recovery and back to full activity and normal lifestyle.
  10. The technique is suitable to treat even large thyroid nodules.

Find out how thyroid nodule Radiofrequency Ablation can help you in a minimally invasive way on our blog post, “Thyroid Nodule Radiofrequency Ablation Treatment: Diagnosis,  Management, and Recovery.”

Find the Right Doctor

From family and internal medicine to specialist, Dr. Manish Taneja is the best in the field.

As a vascular and interventional radiology specialist, Dr Manish Taneja looks after peripheral vascular disease, aneurysms, dialysis interventions, venous diseases like deep vein thrombosis, and varicose veins/spider veins/reticular veins. He is also competent in performing newer endovascular procedures such as uterine artery embolization, prostate artery embolization, genicular artery embolization, and erectile dysfunction interventions.

Dr. Manish Taneja also has extensive experience in performing all vascular interventions, non-vascular interventions and interventional oncology procedures.

Read More About Vascular Treatments on Our Blog

To dive deeper into the types of vascular treatments such as thyroid nodule radiofrequency ablation, head over to our clinic’s blog.  Read our recommended vascular treatments related blog posts to stay informed.

Thyroid Nodule Resources

How to Keep Thyroid Healthy for Optimal Well-Being

As part of the endocrine system, the thyroid hormones must be perfectly balanced at all times for the body to function normally.

Woman holding and using megaphone

Caring For Your Thyroid Health

Have you ever experienced difficulty swallowing or breathing? You may have risk factors including a family history of thyroid nodules or iodine deficiency. Thyroid nodules are abnormal lumps (growths) within the thyroid gland, a butterfly-shaped gland located below your voice box. Even if most thyroid nodules are benign, 10-15% of nodules are cancerous. Sometimes overgrowth of normal thyroid tissue can lead to hyperthyroidism. In other cases, multiple nodules can form in the thyroid called multinodular goiter. Fluid filled thyroid cysts can be one type of thyroid nodule within the thyroid. More complex nodules may lead to thyroid cancers.

Depending on the root cause and type of nodule you have, patients can monitor with regular ultrasound or even have a thyroid fine needle aspiration biopsy (FNAC) if required. Surgery to remove partial or whole thyroid gland can be done but thanks to minimally invasive treatments such as Radiofrequency Ablation (RFA), this procedure can treat noncancerous and cancerous thyroid lumps.

Types of Thyroid Nodules and Cancer

Watch our video guide and find out more on our blog post, “Types of Thyroid Nodules and Cancer” with the types, causes, evaluation, biopsy, treatment options, and when to see a thyroid specialist. Find answers to questions on whether thyroid nodules are cancerous or not.

Arrange Your Appointment

Consult Vascular Specialist, Dr. Manish Taneja

Other Health Conditions

The Supreme Vascular and Interventional Clinic is your “go-to” facility for various conditions and pain management. To arrange an appointment with Dr. Manish Taneja, our thyroid nodule specialist, contact us. You can also call us at (+65) 6904 8084 for a consultation.