To whom should I refer a patient for a fine needle biopsy (FNB) of a thyroid nodule?

Referral for Fine Needle Biopsy of Thyroid Nodules

Refer the patient to an interventional radiologist or a trained clinician (endocrinologist, otolaryngologist, or endocrine surgeon) who performs ultrasound-guided fine needle aspiration biopsy (FNA) in their office or clinic setting.

Primary Referral Options

Interventional Radiology

• Interventional radiologists traditionally perform ultrasound-guided thyroid FNA and have extensive experience with image-guided procedures 1
• Radiology departments typically have dedicated ultrasound equipment and cytopathology support available 1

Office-Based Specialists (Preferred in Many Settings)

• Endocrinologists, otolaryngologists, or endocrine surgeons trained in ultrasound-guided FNA can perform the procedure in their office with comparable accuracy to radiology 2
• Office-based ultrasound-guided FNA by trained physicians demonstrates specimen adequacy rates of 81.2% and allows the primary physician to remain more involved in the patient's overall care 2
• This approach eliminates extra office visits, reduces healthcare costs, and streamlines patient care 2

Key Procedural Requirements

Essential Technical Elements

• The procedure must be performed under ultrasound guidance, as this is the preferred method recommended by multiple guidelines due to superior accuracy, economy, safety, and effectiveness 3
• Ultrasound guidance significantly improves diagnostic accuracy compared to palpation-guided FNA, with sensitivity increasing from 91.8% to 97.1% and global diagnostic accuracy improving from 72.6% to 75.9% 4
• Real-time ultrasound allows continuous visualization of the needle during insertion and sampling, reducing false-negative rates from 2.3% to 1% 4

Cytopathology Support Considerations

• On-site cytopathologist presence is not mandatory for adequate specimen collection 5
• Experienced radiologists or clinicians trained in smear preparation can achieve adequate specimen rates (83.2%) without on-site cytopathology, with no statistically significant difference compared to procedures with on-site cytopathology present (87.3%) 5
• However, on-site evaluation can help determine if additional sampling is needed and may reduce the need for repeat procedures 1

Important Clinical Context

When FNA is Indicated

• All patients with thyroid nodules meeting criteria for biopsy should undergo puncture biopsy to confirm pathological diagnosis, with FNA as the preferred method (strong recommendation, high-quality evidence) 3
• FNA should be performed for any thyroid nodule >1 cm, and for nodules <1 cm if suspicious ultrasonographic features are present (hypoechogenicity, microcalcifications, irregular borders, solid composition, abnormal blood flow) 6

Procedure Specifications

• FNA is performed with a 22-27 gauge needle under ultrasound guidance 1
• The procedure is low-risk with rare complications; most common issues include discomfort, small hematoma, and insufficient sampling 1
• If FNA yields inadequate or indeterminate results, core needle biopsy (CNB) may be necessary, typically performed with an 18-gauge biopsy device 3, 1

Common Pitfalls to Avoid

• Do not refer for palpation-guided FNA alone - ultrasound guidance is essential for optimal diagnostic accuracy and reduces inadequate specimen rates from 8.7% to 3.5% 4
• Avoid referring to providers without ultrasound capability - the procedure must be ultrasound-guided to meet current guideline standards 3, 6
• Be aware that follicular neoplasms may yield indeterminate results requiring surgical excision for definitive diagnosis, as FNA cannot distinguish follicular adenoma from adenocarcinoma 3, 6