Thyroid Biopsy: Fine-Needle Aspiration for Multinodular Goiter

Thyroid nodules are common with a higher prevalence in women and the older population. They can be found in more than 50% of the older population. Malignancy risk is reported to be 7–15% depending on age, sex, radiation exposure history, and family history. Thyroid nodules can be detected either by palpation or incidentally by imaging done for irrelevant purposes. About 16% of chest CT scans show an incidental thyroid nodule. Subsequent ultrasound scans would evaluate the nodule size and characteristics. If the nodules meet the biopsy criteria based on TIRADS (Thyroid Imaging Reporting and Data Systems) criteria, referral for fine-needle aspiration biopsy (FNA) is necessary. This video delivers a thorough demonstration of the correct technique for ultrasound-guided thyroid FNA with rapid on-site cytology evaluation (ROSE).

Thyroid biopsy; thyroid; cytology.

This is a case of multinodular goiter, which was detected over a decade ago. The right inferior and isthmus nodules were biopsied soon after the diagnosis and found to be benign. Ultrasound surveillance had lapsed until the patient was seen by a new primary care physician. A recent ultrasound showed that the left middle thyroid lobe has a new 2.6-cm TIRADS-4¹ nodule that meets biopsy criteria. She is asymptomatic, clinically and biochemically euthyroid. The patient was referred to the thyroid biopsy clinic.

Ultrasound-guided FNA is a clean (but not a sterile) procedure, which can be performed in an office setting to obtain cells or fluid from a nodule by using fine or thin (22- to 27-gauge) needles. The patient is placed in a supine position with neck extension to expose the thyroid. A pillow is placed under the shoulders. After cleaning the neck with an antiseptic agent, skin is marked, and local anesthesia is applied. The patient needs to stay still and avoid swallowing or talking during the procedure.

The biopsy needle can be inserted perpendicular or parallel to the transducer. The entire needle can be seen with the parallel approach; however, only the needle tip can be seen with the perpendicular approach. Here we demonstrate the perpendicular approach. The syringe plunger is pulled back to the 2-mL mark prior to needle insertion. Once the needle tip is in the nodule, gentle rotation and vertical motion within the nodule allow cell dislodging. The specimen is squirted on a glass slide, gently spread and fixed. Typically, 3–4 passes are required per nodule for the cytology analysis and an additional pass for the molecular testing (if it will be obtained). When ROSE is available, cytologists would give immediate feedback regarding the sample adequacy. Satisfactory FNA requires cytologic adequacy (i.e., the presence of at least six groups of follicular cells, each group containing at least 10 epithelial cells, preferably on a single slide).²

Nondiagnostic samples accounted for 2–16% of all FNA samples in a large series. When a thyroid nodule’s FNA cytology is nondiagnostic, a repeat FNA with ultrasound guidance and, if available, on-site cytologic evaluation, is recommended and can increase diagnostic adequacy by 60–80%. Nodules with repeatedly nondiagnostic results but low suspicion on ultrasound should be monitored or considered for surgical excision, while nodules with high-risk features or significant growth may require earlier intervention. Additionally, core-needle biopsy and molecular testing may aid in assessing these nodules, though their clinical impact is still under evaluation.³

Once the adequate sample is obtained, firm pressure is applied on the biopsy site, which is then covered with a Band-Aid. Patients can resume daily activities and light exercise right away; however, strenuous exercise and heavy lifting should be avoided for 24 hours.

• 1% lidocaine
• 70% isopropyl prep pads
• Transducer cover
• Sterile ultrasound gel
• Sterile gauze
• Gloves
• 3-mL syringe with 27-gauge 0.5-inch needle for local anesthesia
• 10-mL syringes with 25-gauge 1.5-inch needles for the biopsy
• Glass slides, CytoLyt
• Molecular testing vial 

Nothing to disclose.

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.