Abstract
OBJECTIVES: To identify the risk of malignancy in the Bethesda III category based on histopathological subclassification. METHODS: We retrospectively analyzed 193 patients with Bethesda III thyroid nodules who underwent surgical resection. The primary outcome was the malignancy risk associated with each histopathological sub-classification. RESULTS: Of 193 patients, final histopathology revealed malignant nodules in 96 (49.7%). The malignancy rates varied among the Bethesda III subcategories, with Hürthle cell atypia of undetermined significance demonstrating the highest rate (55.6%), followed by cytological atypia (55.4%), architectural atypia (50.6%), and combined cytological and architectural atypia (33.3%). However, no significant difference in malignancy rates was observed among the Bethesda III subcategories (p=0.240). Papillary thyroid carcinoma was the most common malignant tumor in all Bethesda III subcategories. CONCLUSION: Bethesda III nodules pose a clinical challenge. Our findings indicate a higher risk of malignancy in patients with cytologic atypia. Bethesda III subclassification may improve clinical decisions and interdisciplinary communication.