Ultrasound Characteristics of Thyroid Nodules: Differentiating Benign from Malignant Nodules Using Histopathology as the Gold Standard.

Background: Thyroid nodules are a common clinical finding. Accurate differentiation between benign and malignant nodules is crucial for determining appropriate management and treatment. Ultrasound is the primary imaging modality for evaluating thyroid nodules, providing valuable information on characteristics such as echogenicity, size, and vascularity. Despite its widespread use, the diagnostic accuracy of ultrasound in distinguishing benign from malignant nodules varies, necessitating further research to establish reliable ultrasound markers. Therefore, this study aimed to evaluate ultrasound characteristics of thyroid nodules to differentiate benign from malignant nodules using histopathology as the gold standard. Materials and Methods: This retrospective study analyzed 175 thyroid nodules from 155 patients who underwent thyroid ultrasound and subsequent fine-needle aspiration (FNA) or core-needle biopsy (CNB) at King Fahad Hospital, Saudi Arabia, between 2021 and 2024. Ultrasound features, including echogenicity, size, and vascularity, were recorded and analyzed. The Chi-square test was used for categorical variables, and the Mann-Whitney U test was employed for nodule size measurements. Results: Out of 175 nodules, 154 were benign and 21 were malignant. A significant association was found between gender and nodule diagnosis (p=0.05), with overall and malignant thyroid nodules more frequently observed in females than in males. Malignant nodules were more likely to be hypoechoic when compared to surrounding normal thyroid tissue than benign nodules (p=0.002). No significant differences were observed in hyperechoic, isoechoic, mixed echogenicity, or vascularity patterns, nor in nodule size dimensions between benign and malignant thyroid nodules. Conclusion: This study highlights the importance of thyroid nodules echogenicity as a predictor of malignancy in thyroid nodules, while other ultrasound features, such as size and vascularity, did not significantly correlate with malignancy. Further prospective, multi-center research is needed to validate these findings and improve diagnostic accuracy in thyroid nodule management.