Multimodal risk assessment of malignancy in thyroidology for nodules with indeterminate cytology

The aim of this study was to evaluate the clinical, ultrasonographic, and elastographic parameters in the risk stratification of malignancy for thyroid nodules with indeterminate cytology according to The Bethesda System for Reporting Thyroid Cytology.

This retrospective, single-center study analyzed 838 thyroid nodules from 716 consecutive patients for six years. The diagnostic performance of nodule size, Doppler ultrasonography features, American Thyroid Association risk of malignancy guidelines, and Tsukuba elasticity scores via strain elastography was assessed. A multinomial logistic regression analysis was employed to compare indeterminate categories (III, IV, and V) with benign cytology (II) to identify independent predictors of malignancy.

Indeterminate nodules exhibited larger mean diameters compared to benign ones (20.83±9.89 vs. 18.65±9.08 mm; p<0.05), and significant associations were identified between III, IV, and V categories and increased peripheral/central vascularization, higher-risk American Thyroid Association risk of malignancy classifications, and elevated Tsukuba elasticity scores (4 and 5). Histopathological malignancy rates were higher in indeterminate groups (p<0.05), whereas patient age and nodule location demonstrated no significant predictive value.

Integrated assessment of nodule size, Doppler vascularity, American Thyroid Association risk stratification, and strain elastography significantly enhances the predictive accuracy for malignancy in nodules with indeterminate cytology. These multiparametric indices provide essential guidance for optimizing surgical indications and clinical management in cases of diagnostic uncertainty.