Management of a 5.7 cm Left Thyroid Nodule Classified as TR3
For a 5.7 cm left thyroid nodule classified as TR3, fine-needle aspiration cytology (FNAC) is strongly recommended as the next step in management. 1
Diagnostic Approach for Thyroid Nodules
- Thyroid nodules larger than 1 cm require FNAC evaluation, especially when classified as TR3 (intermediate risk) 2, 1
- A 5.7 cm nodule significantly exceeds the size threshold for mandatory evaluation, regardless of other risk factors 2, 3
- The primary goal of thyroid nodule evaluation is to determine whether malignancy is present, which occurs in approximately 5-15% of all thyroid nodules 3, 4
Pre-FNAC Assessment
- Serum TSH measurement should be obtained before FNAC, as higher TSH levels are associated with increased risk of differentiated thyroid cancer 1
- Comprehensive neck ultrasonography should be performed to assess:
FNAC Procedure Recommendations
- Ultrasound-guided FNAC is more accurate, economical, and effective than palpation-guided FNAC 1
- The sample should be categorized according to the Bethesda System for Reporting Thyroid Cytopathology 1, 5
- Consider measuring serum calcitonin to rule out medullary thyroid cancer, which has higher sensitivity compared to FNAC 2, 1
Management Based on FNAC Results
- If FNAC confirms malignancy (Bethesda VI), total or near-total thyroidectomy is recommended for nodules ≥1 cm 2
- For indeterminate cytology (Bethesda III/IV), consider molecular testing to guide further management 5, 4
- For benign cytology (Bethesda II), active surveillance may be appropriate with regular follow-up 2
Special Considerations for Large Nodules
- Despite the large size (5.7 cm), nodule size alone is not a reliable predictor of malignancy 6
- Larger nodules (>2 cm) may actually have lower malignancy rates than smaller nodules 6
- However, large nodules warrant evaluation due to potential compressive symptoms and higher false-negative rates in nodules 3-6 cm 6, 4
Follow-up Protocol
- If FNAC confirms benign pathology, regular ultrasound surveillance is recommended 2
- For nodules with suspicious features or indeterminate cytology, surgical consultation is appropriate 2
- If surgery is performed, the extent depends on final histology, with total thyroidectomy for confirmed malignancy and possible lobectomy for more limited disease 7
Remember that while the 5.7 cm size is concerning and requires thorough evaluation, size alone does not definitively indicate malignancy. The TR3 classification suggests intermediate risk, making FNAC the essential next step to guide appropriate management.