Ultrasound Features and Estimated Risk of Malignancy in Thyroid Nodules

Abstract

Introduction: A significant uncertainty surrounding the diagnostic accuracy of ultrasound (US) and the risk features in thyroid nodules exist to date which impacts clinical practice and guidelines. Methods: This retrospective descriptive observational study included patients with thyroid nodules with US reports over 10 years and either had a fine-needle aspiration (FNA) cytology result, a pathology report or both. Results: A total of 483 patients were included. Most of the patients were <55 years old (67.3%) and the majority of them were females (91.3%). The FNA cytology results indicated that 311 (64.4%) of the thyroid nodules were benign and 32 (6.6%) were malignant. Overall, only 181 (37.5%) of the patients had a final histopathologic assessment; of these, 80 (44.2%) had malignant thyroid nodules, 78 (43.1%) had benign nodules, and 23 (12.7%) had microcarcinoma. multivariate logistic regression analysis revealed that having US features of hypoechogenicity (adjusted odd ratio 3.37; 95% confidence interval [CI] 1.03–11.00) and a microlobulated or irregular margin (aOR 3.65; 95% [CI] 1.13–11.79) were the only sonographic characteristics that had a statistically significant association with thyroid cancer based on final pathology. Conclusion: Thyroid nodules showing hypoechogenic echogenicity and microlobulated or irregular margin on US need to be closely followed and given the appropriate management based on their risk criteria.