Long-term surveillance for benign thyroid nodules

The widespread use of high-resolution ultrasonography has significantly improved the detection and assessment of thyroid nodules, leading to the development of standardized sonographic nodule risk stratification systems. These systems aim to reduce unnecessary fine needle aspiration (FNA) biopsies and enhance the consistency of ultrasound reporting. Most benign nodules do not require immediate intervention but instead warrant periodic surveillance, primarily through an ultrasound monitoring. This narrative review summarizes recent literature on the long-term follow-up of benign thyroid nodules, with a focus on ultrasound surveillance strategies and the rationale behind current clinical practice guidelines. Surveillance of benign thyroid nodules typically involves periodic ultrasound examinations, combined often with clinical assessment, to detect significant growth, identify changes suggestive of false-negative classification, and exclude the appearance of compressive symptoms. While an increase in nodule size has traditionally raised concerns about potential malignancy, recent evidence suggests that benign nodules may also increase in size over time. Current clinical practice guidelines recommend regular monitoring of untreated benign thyroid nodules to detect any changes in size or appearance. Follow-up intervals vary according to multiple factors (age, sonographically estimated risk, size, previous cytology), and there is a need for further research to establish optimal protocols.