EVIDENCE-BASED ANSWER:
IN THE ABSENCE OF OUTCOME STUDIES, experts recommend ultrasound evaluation of nontoxic mulinodular goiters (MNG) followed by fine-needle aspiration (FNA) of suspicious nodules (strength of recommendation [SOR]: C, consensus-based guidelines).
Thyroid hormone suppression therapy reduces the size of MNG (SOR: A, systematic review of randomized controlled trials [RCTs]), but it risks inducing hyperthyroidism (SOR: C, expert opinion).
Experts recommend thyroidectomy for compressive symptoms, progressive growth, or ultrasound or FNA results indicating thyroid cancer (SOR: C, consensus based guidelines).
Expert guidelines recommend repeat ultrasound at 6 to 18 months to follow up benign nodules or nonendemic MNG in patients at low risk of malignancy and subsequent follow-up of stable nodules every 3 to 5 years (SOR: C, consensus-based guidelines).
EVIDENCE SUMMARY
This summary updates the 2007 Clinical Inquiry, “What is the best approach to goiter for euthyroid patients?”1
Initial evaluation of palpable goiter with a normal thyrotropin
In the United States, MNG is generally nonendemic and unrelated to iodine deficiency, as distinguished from endemic goiter caused by iodine deficiency in other parts of the world.
Our structured search of the literature found no randomized trials or prospective cohort studies comparing diagnostic approaches. The American Association of Clinical Endocrinologists’ (AACE) 2010 guidelines and American Thyroid Association (ATA) guidelines recommend ultrasound for all MNG.2,3 The AACE guidelines recommend thyroid scintigraphy when clinicians suspect retrosternal MNG.2
Ultrasound findings can change management, avoid biopsy
In a retrospective analysis of 223 patients with nodular thyroid disease, thyroid ultrasound altered clinical management of 63% of patients with abnormal thyroid exams.4 A single center retrospective cohort study of 650 FNA biopsies identified 4 morphologic patterns on ultrasound that predicted benign cytology with 100% specificity. The authors concluded that using ultrasound pattern to determine which patients require FNA could have obviated more than 60% of thyroid biopsies.5
Thyroid hormone suppression therapy risks hyperthyroidis
A systematic review of 9 RCTs of 18-month or shorter duration found that thyroid hormone suppression therapy reduced benign thyroid nodule volume (relative risk=1.88 compared with placebo or no treatment; 95% confidence interval [CI], 1.18-3.01; P=.008). The number needed to treat was 8 to reduce volume by >50% (risk difference=0.13; 95% CI, 0.06-0.19; P=.0003).6 However, thyroid hormone suppression therapy risks inducing hyperthyroidism and is not routinely recommended by the AACE or the ATA.2,3