[Ultrasound in secondary prevention of thyroid nodules-evidence, benefits, and limitations]

Thyroid nodules are common incidental findings in ultrasound examinations. Early detection by ultrasound does not seem to have any patient-relevant benefits in terms of secondary prevention.

The current article provides an overview of international evidence for the benefits and harms of ultrasound in the secondary prevention of thyroid nodules.

A narrative review (PubMed search; 2010-2025) of guidelines (American Thyroid Association, ATA; American Association of Clinical Endocrinology, AACE/American College of Endocrinology, ACE; European Thyroid Association, ETA; United States Preventive Services Task Force, USPSTF; National Institute for Health and Care Excellence, NICE; German-language S3 guidelines), population-based studies (SHIP, KORA, SEER), and systematic reviews and meta-analyses was performed.

The prevalence of thyroid nodules is high, but the proportion of clinically relevant or malignant findings is very low. Mortality from thyroid cancer is also low. Screening asymptomatic adults with ultrasound increases the incidence of mostly indolent papillary carcinomas without any reduction in mortality. The risk of overdiagnosis and subsequent overtreatment is substantial. Thus, international and national guidelines do not recommend screening for early detection of thyroid cancer. Standardized ultrasound risk classifications (e.g., European Thyroid Imaging Reporting and Data System, EU-TIRADS/American College of Radiology TIRADS, ACR TIRADS) are essential for targeted evaluation in cases of clinically suspected thyroid cancer.

Screening asymptomatic individuals using ultrasound is not recommended. The rate of overdiagnosis is high, and the benefits in terms of reducing morbidity or mortality have not been proven.