The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) classifies FNA results into 6 categories. A Bethesda Category IV (Follicular Neoplasm/Suspicious for Follicular Neoplasm) carries an estimated risk of malignancy of approximately:
- A 1–4%
- B 50–75%
- C 10–40% ✓
- D 95–99%
Correct answer: C. 10–40%
Explanation
TBSRTC Category IV (Follicular Neoplasm/Suspicious for Follicular Neoplasm) carries an implied risk of malignancy of 10–40% (updated TBSRTC 3rd edition 2023: ~25–40%). This category warrants diagnostic surgical excision (hemithyroidectomy or lobectomy) as FNA cannot distinguish follicular adenoma from follicular carcinoma, which requires histological demonstration of capsular/vascular invasion. Category VI (malignant) carries 97–99% malignancy risk.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.