How is a Thyroid Biopsy Performed?

A thyroid biopsy is a procedure to obtain a cell sample from thyroid nodules to determine whether they are benign or malignant. It can be safely performed in the presence of interventional radiology, mostly under ultrasound guidance and with local anesthesia. The goal is to make an early and accurate diagnosis to avoid unnecessary surgeries and expedite treatment when necessary.

Why is a thyroid biopsy requested?

• Nodules of 1 cm and larger with risky ultrasound findings (e.g., microcalcifications, irregular margins, high TI-RADS score)
• Nodules smaller than 1 cm but with high-risk factors (family history, previous neck radiation, rapid growth)
• Presence of suspicious lymph nodes
• Re-evaluation of nodules previously reported as suspicious/borderline

Types of Biopsy

Fine-Needle Aspiration Biopsy (FNAB, FNA)

Cell aspiration is performed with a very thin needle under ultrasound guidance. It is the first and sufficient step for most patients; the risk of complications is low, and discharge is provided on the same day.

Core Needle (Tru-Cut) Biopsy

A tissue cylinder, not just cells, is obtained. It is preferred when FNA is insufficient, when there are repeated uncertain results, or in the differential diagnosis of conditions such as lymphoma or thyroiditis.

How is the procedure performed?

Preparation

Some minor preparations are needed before coming for a thyroid biopsy. The goal is to complete the procedure safely and smoothly. It is sufficient to comply with the following:

• Do not stop your blood-thinning medications on your own. Your doctor will adjust the dose or timing if necessary.
• You generally do not need to fast; you will be notified before the appointment if there is a different situation.
• You remove jewelry from your neck and sign a brief consent form.

Application

The procedure is completed in a few minutes using a fine needle under ultrasound guidance. Most people only feel a slight prick. The following steps are standard:

• The nodule to be biopsied is clearly visualized with ultrasound.
• The neck skin is numbed with local anesthesia; this minimizes pain.
• The fine needle is inserted briefly 2–4 times to take a sample, which is then prepared for pathology.
• The entire procedure usually takes 10–20 minutes.

Post-Procedure

A short rest after the procedure is sufficient; you can return to your daily life on the same day. Paying attention to the following recommendations speeds up recovery:

• You will have a small bandage on your neck. A short observation period of 1–2 hours may be performed if your center deems it appropriate.
• You can eat and drink normally on the same day. Only avoid heavy exercise for 24 hours.
• Mild pain and tenderness may occur. Ice application and simple painkillers are usually sufficient.

What are the advantages of using ultrasound for the procedure?

Ultrasound ensures that the needle goes to the exact correct point and reduces potential risks. This avoids unnecessary interventions. Suspicious foci are targeted with millimetric accuracy. The risk of bleeding is reduced because blood vessels are visible. If there are multiple nodules, the one appearing riskiest is prioritized.

Are there side effects or risks?

The procedure is generally safe; observed effects are usually mild and temporary. You should contact your doctor if an unexpected situation occurs:

• Tenderness and minor bruising on the neck are common and resolve spontaneously.
• Rarely, bleeding/hematoma may develop; pressure and short observation are usually sufficient.
• Infection is very rare; consult a doctor immediately if you have fever or severe pain.
• Hoarseness is unusual; evaluation is necessary if it develops.

Cysts and minimal surgical treatments

In recurrent cystic nodules, biopsy aids diagnosis; if complaints persist, ethanol ablation may be considered with interventional radiology. In selected patients with solid benign nodules, microwave or RFA ablation can be an alternative to surgery. Suitability must be evaluated in a multidisciplinary board.

Who may not be suitable?

• Uncontrolled bleeding disorder,
• Severe anticoagulation that cannot be regulated,
• In cases of active neck infection, planning is personalized by performing a risk–benefit analysis.