Management of Asymptomatic Multinodular Goiter
For patients with asymptomatic multinodular goiter, the recommended approach is active surveillance with annual clinical evaluation and TSH measurement, combined with ultrasound to identify nodules requiring fine-needle aspiration biopsy based on suspicious features. 1, 2
Initial Diagnostic Evaluation
Ultrasound is the mandatory first-line imaging study to confirm thyroid origin, characterize nodule morphology, and stratify malignancy risk using standardized criteria. 1, 3
- Measure serum TSH as the most sensitive initial test (98% sensitivity, 92% specificity) to assess thyroid function. 1
- Thyroglobulin measurement is not helpful for diagnosis. 3
Fine-needle aspiration cytology (FNAC) should be performed selectively, not routinely on all nodules:
- Nodules >1 cm with suspicious ultrasound features (hypoechogenicity, microcalcifications, irregular borders, solid aspect, taller-than-wide shape, intranodular blood flow). 3
- Nodules <1 cm only if clinical risk factors present (history of head/neck irradiation, family history of thyroid cancer, cervical adenopathy). 3
- In multinodular goiter specifically, only nodules with suspicious ultrasound features require FNAC. 3
Surveillance Strategy for Asymptomatic Patients
For small, asymptomatic multinodular goiters with normal TSH and benign FNAC results, yearly evaluation with TSH measurement and thyroid palpation is sufficient. 4
- Periodic follow-up should include neck palpation and ultrasound examination. 2
- Levothyroxine suppression therapy is controversial and generally not recommended for nontoxic multinodular goiter, as it is often unsuccessful and carries risk of iatrogenic hyperthyroidism. 4, 5
- Thyroid hormone suppression should never be used in patients with already suppressed TSH levels. 4
When to Escalate Management
Surgery becomes the preferred treatment when any of the following develop:
- Local compression symptoms (dysphagia, choking sensation, airway obstruction, respiratory distress). 4, 2, 5
- Malignant or suspicious cytology on FNAC. 2, 5
- Cosmetic concerns causing significant distress. 4, 5
- Development of hyperthyroidism (toxic multinodular goiter). 4, 5
If respiratory symptoms emerge, obtain CT scan to evaluate substernal extension and degree of tracheal compression before surgical planning, as CT is superior to ultrasound for this assessment. 1, 6
Special Considerations
Molecular testing (BRAF, RAS, RET/PTC, PAX8/PPARγ mutations) may be considered for indeterminate cytology, as mutation-positive nodules have ~97% malignancy rate at histology. 3
Serum calcitonin measurement should be part of the diagnostic evaluation to screen for medullary thyroid carcinoma (5-7% of thyroid cancers), as it has higher sensitivity than FNAC for this diagnosis. 3
Radioactive iodine is not indicated for asymptomatic nontoxic multinodular goiter and should be reserved for toxic multinodular goiter or specific scenarios where surgery is contraindicated. 2, 7
Critical Pitfall
Do not perform radionuclide scanning as the initial study in euthyroid patients, as it does not help determine malignancy risk or guide biopsy decisions and has low positive predictive value. 1