Association of Tumor Size With Histologic and Clinical Outcomes Among Patients With Cytologically Indeterminate Thyroid Nodules

Importance Tens of thousands of unnecessary operations are performed each year for diagnostic purposes among patients with cytologically indeterminate thyroid nodules. Whereas a diagnostic lobectomy is recommended for most patients with solitary indeterminate thyroid nodules, a total thyroidectomy is preferred for nodules larger than 4 cm. Objective To determine whether histologic or clinical outcomes of indeterminate thyroid nodules 4 cm or larger are worse than those for nodules smaller than 4 cm, thus justifying a more aggressive initial surgical approach. Design, Setting, and Participants In this retrospective cohort study, 652 indeterminate thyroid nodules (546 nodules Exposure Tumor size. Main Outcomes and Measures Differences in cancer rates, rates of invasive features, cancer aggressiveness, and response to therapy between indeterminate thyroid nodules smaller than 4 cm and 4 cm or larger. Results A total of 652 indeterminate thyroid nodules (546 nodules Conclusions and Relevance Most indeterminate thyroid nodules are benign or low-risk malignant tumors regardless of tumor size. In the absence of other indications for total thyroidectomy, this study suggests that a thyroid lobectomy is sufficient initial treatment for most solitary cytologically indeterminate thyroid nodules independent of the tumor size.