Objective:

To evaluate the predictive value of thyroid hormone sensitivity indices and hematological inflammatory markers for malignancy in thyroid nodules classified as AUS, emphasizing their combined role with ultrasonographic features.

Key Findings:

• 30.8% of surgically treated cases were malignant.
• Family history of thyroid cancer was more frequent in the malignant group (26.3% vs 10.9%, p=0.008).
• Malignant nodules exhibited specific ultrasonographic features: solid composition, hypoechoic appearance, microcalcifications, irregular margins, and intranodular vascularity.
• Higher TSH and thyroid hormone sensitivity indices (TT4RI, TSHI, TFQI) were found in malignant nodules.
• EU-TIRADS classification, family history, intranodular vascularity, and thyroid hormone sensitivity indices were independent predictors of malignancy.

Interpretation:

Thyroid hormone sensitivity indices can enhance malignancy risk stratification in Bethesda category III thyroid nodules, complementing ultrasonographic assessments.

Limitations:

• Retrospective design may introduce selection bias, potentially affecting the generalizability of the findings.
• Exclusion of patients with certain conditions limits generalizability, particularly regarding the applicability of findings to broader populations.

Conclusion:

Thyroid hormone sensitivity indices may serve as adjunctive markers for malignancy risk in AUS thyroid nodules, aiding clinical decision-making.