What are the next steps in managing a patient with a thyroid ultrasound showing heterogeneous echotexture, bilateral nodules, and a TI-RADS (Thyroid Imaging Reporting and Data System) score of 3, indicating mild suspicion of malignancy?

Management of Thyroid Nodules with TI-RADS 3 Classification

For a patient with thyroid nodules classified as TI-RADS 3 (mild suspicion of malignancy), fine-needle aspiration (FNA) biopsy should be performed for nodules ≥1.5 cm in size. 1

Assessment of Current Findings

• The ultrasound shows heterogeneous echotexture with bilateral nodules, including:
  • Right lobe: Mixed nodule in lower right lobe (0.89 × 0.75 × 1.06 cm), mid right lobe nodule (0.71 × 0.71 × 0.93 cm), and solid isoechoic nodule in lower right lobe (0.54 × 0.52 cm) 2
  • Left lobe: Mixed nodule in upper left lobe (1.34 × 1.01 cm) 2
• The nodules show solid isoechoic patterns with smooth borders, intra-nodular flow on Doppler, and no micro or macro calcifications 2
• The TI-RADS 3 classification indicates mild suspicion for malignancy 3

Next Steps in Management

• Thyroid function tests should be performed as the first laboratory assessment to evaluate thyroid function 1
• Fine-needle aspiration (FNA) biopsy is indicated for the left upper lobe nodule (1.34 × 1.01 cm) as it approaches the size threshold of 1.5 cm for TI-RADS 3 nodules 1, 4
• The right lobe nodules are all under 1.5 cm in size and do not require immediate FNA based on ACR TI-RADS guidelines 4

Rationale for FNA Recommendation

• TI-RADS 3 nodules have a lower risk of malignancy compared to TI-RADS 4 or 5, but still warrant evaluation when they meet size criteria 3, 5
• Studies have shown that TI-RADS scoring correlates with malignancy risk, with higher scores (4-5) having significantly higher rates of malignancy than lower scores (1-3) 6, 7
• The absence of suspicious features (irregular margins, microcalcifications, taller-than-wide shape) in these nodules is reassuring 2, 5

Follow-up Recommendations

• For nodules not meeting FNA criteria, ultrasound follow-up in 12 months is appropriate to assess for stability 1
• If FNA results are benign, continued ultrasound surveillance is recommended at 12-24 month intervals 1
• If FNA results are indeterminate or suspicious for malignancy, further management would include possible molecular testing or surgical consultation 1

Important Considerations

• While most thyroid nodules are benign, proper evaluation is essential to identify the minority that are malignant 1
• The risk of malignancy in TI-RADS 3 nodules is approximately 5-10% 3, 7
• Overdiagnosis and overtreatment of small, indolent thyroid nodules is a concern, which is why size thresholds are used in management algorithms 4
• False-negative results can occur in 5-10% of FNA biopsies, so clinical suspicion should remain if other concerning features develop during follow-up 8