What is the management plan for a patient with nodular goiter?

Management Plan for Nodular Goiter

Initial Diagnostic Evaluation

Begin with thyroid ultrasound as the first-line imaging modality, supplemented by fine needle aspiration cytology (FNAC) for nodules meeting specific criteria. 1

Step 1: Assess Thyroid Function

• Measure serum TSH to determine if the goiter is toxic (hyperthyroid) or nontoxic (euthyroid) 1
• If TSH is suppressed, proceed with evaluation for toxic multinodular goiter or autonomous functioning adenoma 2
• Measure free T4 and free T3 if TSH is abnormal 3

Step 2: Imaging Assessment

• Perform high-resolution thyroid ultrasound to characterize nodule features including size, composition, echogenicity, margins, calcifications, and shape 4, 5
• Apply ACR TI-RADS criteria to stratify malignancy risk for each nodule 5
• Add CT without IV contrast if there is suspected substernal extension or tracheal compression symptoms (dysphagia, choking, airway obstruction) 4, 5

Step 3: Fine Needle Aspiration Biopsy

• Perform FNAC on any nodule >1 cm 1
• Perform FNAC on nodules <1 cm if suspicious ultrasound features are present (hypoechogenicity, microcalcifications, irregular borders, taller-than-wide shape, intranodular blood flow) 1
• In multinodular goiter, biopsy nodules with the most suspicious ultrasound characteristics 1
• Measure serum calcitonin as part of the diagnostic evaluation to screen for medullary thyroid cancer 1

Step 4: Manage Based on FNAC Results

• If cytology is malignant: Refer immediately for total or near-total thyroidectomy 1
• If cytology shows follicular neoplasia: Proceed to surgery if TSH is normal and thyroid scan shows "cold" appearance 1
• If cytology is inadequate: Repeat FNAC with ultrasound guidance 1
• If cytology is benign: Proceed to management based on symptoms and functional status 2

Management of Nontoxic Nodular Goiter

For Asymptomatic Patients with Benign Cytology

• Observe with annual clinical follow-up including neck palpation and ultrasound examination 2, 6
• Monitor serum TSH yearly to detect development of autonomy 6
• Do not routinely use levothyroxine suppression therapy, as it is often unsuccessful in reducing goiter size and carries risk of iatrogenic hyperthyroidism 6, 7

For Symptomatic Patients (Compression Symptoms)

• Surgery is the preferred definitive treatment for large goiters causing dysphagia, choking sensation, or airway obstruction 2, 6
• Obtain CT scan preoperatively to evaluate substernal extension and degree of tracheal compression 4, 5
• Radioactive iodine (I-131) is an alternative if adequate uptake is demonstrated on thyroid scan, though surgery achieves more rapid symptom relief 3, 6

For Cosmetic Concerns

• Surgery remains the first-choice treatment for large visible goiters causing cosmetic complaints 7
• Radioiodine may be considered if thyroid uptake is adequate 7

Management of Toxic Multinodular Goiter

Initial Medical Management

• Use methimazole as first-line antithyroid drug to ameliorate hyperthyroid symptoms in preparation for definitive therapy 8
• Use propylthiouracil only if patient is intolerant of methimazole 9
• Thionamides are not recommended for long-term management; they serve only as a bridge to definitive therapy 3

Definitive Treatment Options

• Surgery or radioactive iodine are both recommended definitive treatments 6
• Surgery achieves more rapid euthyroid state, particularly for large goiters with large autonomously functioning nodules 6
• Radioiodine is effective for many patients but requires adequate uptake and may take longer to achieve euthyroid status 3, 6

Common Pitfalls to Avoid

• Do not rely on CT or MRI alone to differentiate benign from malignant nodules—these modalities have limited utility for this purpose and FNAC remains essential 4
• Do not use levothyroxine suppression routinely in patients with normal or suppressed TSH, as this risks causing iatrogenic thyrotoxicosis without proven benefit 6, 7
• Do not assume multinodular goiter has lower cancer risk than solitary nodules—malignancy rates are equivalent, requiring the same vigilance with FNAC 2, 7
• Do not miss substernal extension—ultrasound has limitations in evaluating inferior disease borders, so add CT when clinical suspicion exists 4, 5
• Do not forget to measure calcitonin—this is the most sensitive test for medullary thyroid cancer and should be part of routine nodule evaluation 1