What is the initial evaluation and treatment for a patient presenting with a thyroid goiter?

Initial Evaluation and Management of Thyroid Goiter

Begin with thyroid function tests (TSH) and thyroid ultrasound as the essential first-line evaluation for any patient presenting with suspected goiter. 1, 2

Initial Diagnostic Workup

Laboratory Testing

• Measure serum TSH first to determine thyroid functional status, as this guides all subsequent management decisions 1
• If TSH is subnormal, the patient has thyrotoxicosis requiring different evaluation (see below) 1
• Consider serum calcitonin measurement to screen for medullary thyroid carcinoma, though this remains somewhat controversial in the United States 1

Imaging Strategy

First-Line Imaging:

• Thyroid ultrasound is the mandatory initial imaging modality to confirm the neck mass originates from thyroid tissue and characterize goiter size and morphology 1, 2, 3
• Ultrasound identifies whether the goiter is diffuse or nodular and evaluates for suspicious nodule features requiring biopsy 1, 2

Add CT Neck (Without IV Contrast) When:

• Obstructive symptoms are present (dyspnea, orthopnea, obstructive sleep apnea, dysphagia, dysphonia) 1, 3
• Substernal extension is suspected, as CT is superior to ultrasound for evaluating retrosternal goiter and quantifying tracheal compression 1, 2, 3
• Planning surgical approach, as CT better defines deep extension to retropharyngeal space 1

MRI is an alternative to CT but less preferred due to respiratory motion artifact 1, 2

Management Based on Thyroid Function Status

Euthyroid Goiter (Normal TSH)

For Asymptomatic Goiter:

• Observation is reasonable for small, asymptomatic goiters 4
• Thyroxine suppression therapy has limited and short-lived effectiveness in euthyroid patients 4
• Radioactive iodine ablation is another medical option but also has limitations 4

For Symptomatic Goiter with Compression:

• Surgical management (thyroidectomy) is recommended for goiters causing compressive symptoms 4
• Symptoms of dyspnea, orthopnea, and dysphagia are more commonly associated with thyromegaly, particularly substernal goiters 4
• Multiple studies demonstrate improved breathing and swallowing outcomes after thyroidectomy 4
• Careful preoperative planning includes assessment of airway, type of anesthesia, and intubation approach 4

Thyrotoxic Goiter (Subnormal TSH)

Imaging for Thyrotoxicosis:

• Three equivalent first-line options: thyroid ultrasound, I-123 radionuclide uptake and scan, or I-131 radionuclide uptake with Tc-99m pertechnetate scan 2
• Radionuclide scanning confirms the entire goiter consists of thyroid tissue and identifies hypofunctioning or isofunctioning nodules requiring biopsy in multinodular goiter 1, 2

Initial Medical Management:

• Start beta-blocker therapy immediately to lower heart rate to nearly normal, which improves tachycardia-mediated ventricular dysfunction 1
• Beta-blockers provide rapid improvement in cardiac and other symptoms while definitive therapy is arranged 1

Nodule Evaluation Within Goiter

If nodular goiter is identified on ultrasound:

• Apply ACR TI-RADS or other risk stratification criteria to determine which nodules require fine needle aspiration (FNA) based on size and sonographic features 1
• Suspicious ultrasound features include: hypoechogenicity, microcalcifications, irregular borders, central hypervascularity, and absence of peripheral halo 1
• FNA is recommended as the first diagnostic test for suspicious nodules ≥1 cm 1
• Ultrasound of central and lateral neck evaluates for suspicious lymph nodes 1

Common Pitfalls to Avoid

• Do not rely on CT or MRI alone to differentiate benign from malignant nodules—these modalities cannot make this distinction unless gross invasion or metastatic disease is present 1, 2
• Do not use FDG-PET/CT for initial goiter evaluation—there is no evidence supporting its use in this setting 1
• Do not perform radionuclide scanning in euthyroid patients to determine malignancy risk—it has low positive predictive value since most nodules are "cold" and most cold nodules are benign 1
• Do not delay surgical referral in patients with significant compressive symptoms, as medical therapy has limited efficacy and symptoms indicate mechanical compression requiring definitive treatment 4
• Be aware that tracheal compression from substernal extension is the primary cause of respiratory distress, not recurrent laryngeal nerve palsy 3