Frozen Section-Guided Selective Ipsilateral Central Neck Dissection in Bethesda V-VI Thyroid Nodules

The goal of this observational pilot cohort study is to evaluate the feasibility and clinical implications of frozen section analysis-guided selective ipsilateral central neck dissection in adult patients undergoing primary thyroid surgery for Bethesda V-VI thyroid nodules with a clinically node-negative neck. The main questions it aims to answer are: * Can intraoperative frozen section analysis of ipsilateral level VI lymph nodes meaningfully inform real-time surgical decision-making? * Can this strategy support tailored escalation or de-escalation of central compartment surgery while minimizing unnecessary bilateral central neck dissection and its associated morbidity? Researchers will compare patients managed with ipsilateral central neck dissection and intraoperative frozen section analysis with patients managed without frozen section analysis, in order to evaluate differences in treatment adequacy, surgical decision-making, and pathological nodal assessment. Participants will undergo primary thyroid surgery according to institutional practice. In patients managed with the frozen section analysis-guided strategy, one or more ipsilateral level VI lymph nodes will be removed during surgery and examined intraoperatively. The result of frozen section analysis may be used to guide the extent of central compartment surgery and the overall surgical strategy.