What is the appropriate evaluation and treatment for an adult patient with no prior medical history presenting with a goiter?

Evaluation and Treatment of Goiter in Adults

Initial Evaluation

Thyroid ultrasound is the first-line imaging study for any adult presenting with goiter, followed immediately by thyroid function testing (TSH, free T4, and free T3). 1, 2

Laboratory Assessment

• Measure TSH first as it is the most sensitive initial test for detecting thyroid dysfunction (98% sensitivity, 92% specificity) 3
• Obtain free T4 and free T3 simultaneously to directly assess biologically active hormones and detect T3-toxicosis, which can occur in multinodular goiter 3
• TSH <0.1 mU/L indicates hyperthyroidism; TSH >6.5 mU/L indicates hypothyroidism 3

Imaging Strategy

• Ultrasound confirms thyroid origin, characterizes goiter morphology, evaluates nodule characteristics, and stratifies malignancy risk using ACR TI-RADS criteria 1, 2
• Add CT neck without IV contrast if substernal extension is suspected or if the patient has respiratory symptoms (dyspnea, orthopnea, stridor, dysphagia) 1, 4, 2
• CT is superior to ultrasound for evaluating tracheal compression and retrosternal extension 4, 2

Fine-Needle Aspiration Biopsy

• Perform FNA only after ultrasound characterization, using ACR TI-RADS criteria to select suspicious nodules 2, 5
• Do not biopsy as the initial diagnostic step 2
• Radionuclide scanning has no role in initial evaluation of euthyroid patients with goiter 2

Treatment Algorithm

Asymptomatic Euthyroid Goiter

For small, asymptomatic goiters with normal TSH and benign FNA results, annual observation with TSH measurement and thyroid palpation is sufficient. 6, 5

• Levothyroxine suppression therapy is controversial and often unsuccessful for multinodular goiter 6, 7
• Avoid levothyroxine in patients with suppressed TSH to prevent iatrogenic hyperthyroidism 6, 7

Symptomatic Nontoxic Goiter

Surgery is the preferred treatment for large goiters causing compressive symptoms (dysphagia, choking, airway obstruction) 6, 5, 7

• Radioactive iodine is an alternative option, particularly for patients who are poor surgical candidates 8, 5, 7
• Levothyroxine suppression has limited efficacy for size reduction in established multinodular goiter 6

Toxic Goiter (Hyperthyroid)

Definitive treatment with either surgery or radioactive iodine is recommended for toxic multinodular goiter or autonomous functioning thyroid adenoma. 6, 8

• Surgery achieves euthyroid status more quickly, especially for large goiters with large autonomous nodules 6
• Thionamides (carbimazole, propylthiouracil) control hyperthyroidism temporarily but are used only as preparation for definitive therapy 8, 9

Malignancy Concerns

Any nodule with malignant or suspicious (indeterminate) cytology requires surgical referral. 5

• Most indeterminate nodules ultimately prove benign, but surgery is generally advised unless autonomous function can be confirmed by scintigraphy 5

Critical Pitfalls to Avoid

• Do not perform radionuclide scanning in euthyroid patients as it does not determine malignancy risk and has low positive predictive value 2
• Do not use levothyroxine suppression in patients with suppressed TSH as this risks iatrogenic hyperthyroidism 6, 7
• Do not overlook substernal extension—obtain CT if there are any respiratory symptoms or if physical exam suggests retrosternal component 1, 4
• Do not assume all nodules in multinodular goiter are benign—approximately 5% harbor malignancy and require systematic ultrasound evaluation with selective FNA 5