Thyroid Fine-Needle Aspiration Biopsy — Technique
Ultrasound-guided thyroid fine-needle aspiration biopsy (FNA) uses a 25G needle to obtain cellular specimens from nodules; diagnostic adequacy is approximately 90%, and it is the standard diagnostic method per ATA 2015 and ETA guidelines.
In the thyroid and parathyroid surgery glossary, Thyroid Fine-Needle Aspiration Biopsy — Technique links the patient's wording with the examination questions that matter. Ultrasound-guided thyroid fine-needle aspiration biopsy (FNA) uses a 25G needle to obtain cellular specimens from nodules; diagnostic adequacy is approximately 90%, and it is the standard diagnostic method per ATA 2015 and ETA guidelines. Duration, side pattern, recurrence, comorbidity and prior treatment response all shape how this entry is interpreted. the clinical point assessment interprets neck examination, the dictionary entry nodule behavior, this topic hormone balance, this term vocal fold mobility and the finding family history together. The page prepares a safer consultation agenda without replacing personal assessment. For this entry, the existing summary aims to connect the reported complaint with examination findings: US-guided FNA reduces the non-diagnostic rate by ~50% compared to palpation guidance and improves accuracy. The topic is therefore read with clinical context, not as a one-line definition.
During the clinical point examination, the clinician first clarifies what the patient experiences and then checks how well objective findings match it. Daily impact, warning signs and older reports are read together. this topic review may combine ultrasound findings, this term laboratory results, the finding fine-needle biopsy and this entry laryngoscopic vocal fold assessment when useful. the clinical point decisions weigh nodule size, the dictionary entry ultrasound pattern, this topic lymph-node appearance, this term prior biopsy result and the finding risk profile separately. In this entry, the clinical aim is to prove the finding that explains the complaint and separate similar-looking conditions: Aspirin/NSAIDs should be stopped 7 days before and DOACs 3–5 days before; INR check is required when a coagulopathy is suspected. Tests are requested when they help make that distinction. Diagnostic steps should improve decision quality instead of repeating tests by habit.
Care steps for this term move from reversible causes toward persistent structural problems. Conservative options are discussed first when safe, with procedures considered only when the finding justifies them. the finding planning discusses observation, this entry medical adjustment, the clinical point lobectomy-total thyroidectomy, the dictionary entry parathyroid strategy or this topic neck dissection by findings. Management of this term is individualized according to symptom duration, examination findings, functional impact, patient expectations, prior treatment response and imaging or laboratory results when needed. Benefit has to be weighed against follow-up burden.
The the finding follow-up plan depends on treatment type, risk level and pace of recovery. this entry follow-up reviews calcium balance, the clinical point voice quality, the finding wound healing, this entry pathology results and the clinical point hormone replacement together. Safe communication about the dictionary entry helps patients notice risky symptoms early without increasing anxiety and supports adherence to follow-up advice. New bleeding, rapid worsening or category-specific warning signs are documented separately from routine timing.
Writing questions about this topic before the appointment helps the patient discuss diagnostic possibilities, treatment limits, review timing and safety warnings more clearly.
In short notes older report wording supports clearer examination questions.
During clinical discussion older report wording supports clearer examination questions.
Procedure and Technique
The patient lies supine with neck extension. The nodule is visualised with a 7.5–15 MHz linear probe; Doppler identifies vascular structures. The needle is inserted via long-axis (in-plane) or short-axis (out-of-plane) approach; long-axis provides superior needle visibility. The 25G needle is directed to the solid component, avoiding cystic areas. Three to four back-and-forth passes are made, then the specimen is applied to a glass slide or placed in liquid medium.
Bethesda Result and Management
Bethesda I (non-diagnostic): repeat FNA recommended in 3 months. II (benign): surveillance US sufficient. III (AUS/FLUS): repeat biopsy or molecular testing. IV (follicular neoplasm): molecular test or diagnostic lobectomy. V (suspicious for malignancy): preparation for surgery. VI (malignant): treatment planning. Malignancy risk is 5–15% for Bethesda III and 15–30% for Bethesda IV.
When to Seek Care
Referral to an endocrinology or thyroid surgery clinic for FNA is indicated when ACR TI-RADS size thresholds are met (TR5≥1 cm, TR4≥1.5 cm, TR3≥2.5 cm). Neck swelling, dyspnoea, or severe pain after the procedure warrants urgent evaluation.
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This glossary entry is for informational purposes only and does not constitute medical advice. Consult a qualified specialist for diagnosis and treatment.