What is the recommended management for a patient with a single thyroid nodule less than 1cm, no recent follow-up ultrasound in 4 years, and current symptoms of tightness in the thyroid area?

Management of Small Thyroid Nodule with New Symptoms After 4-Year Gap

Perform a repeat ultrasound examination now to reassess the nodule's size, characteristics, and risk stratification, followed by ultrasound-guided fine-needle aspiration if the nodule has grown to ≥1 cm or demonstrates suspicious sonographic features. 1, 2

Rationale for Repeat Ultrasound

• The 4-year surveillance gap requires immediate imaging reassessment, as current guidelines recommend periodic ultrasound follow-up for small thyroid nodules to detect interval growth or development of suspicious features. 3, 4

• New symptoms of "tightness" warrant investigation to determine if the nodule has enlarged, developed compressive features, or if other pathology has emerged. 5, 6 While most thyroid nodules remain asymptomatic, approximately 5% can cause compressive symptoms such as choking sensation or pressure. 5

• Nodules <1 cm at initial presentation have low clinical significance, but serial monitoring is essential because a subset may grow or develop high-risk features over time. 1 The original nodule being <1 cm likely meant FNA was appropriately deferred initially, but this decision requires periodic reassessment. 1, 2

Ultrasound-Based Decision Algorithm

If the nodule remains <1 cm on repeat ultrasound:

• FNA is indicated only if suspicious features are now present, including marked hypoechogenicity, microcalcifications, irregular/microlobulated margins, absence of peripheral halo, solid composition, or central hypervascularity. 1, 2

• Surveillance without FNA is appropriate if the nodule remains <1 cm without suspicious sonographic features and no concerning clinical factors (no history of head/neck irradiation, no family history of thyroid cancer, no suspicious cervical lymphadenopathy). 1, 2

If the nodule has grown to ≥1 cm:

• Proceed directly to ultrasound-guided FNA regardless of sonographic appearance, as this size threshold mandates tissue diagnosis per multiple guideline recommendations. 1, 2, 7 The combination of growth over time and new symptoms strengthens this indication. 6, 4

• Measure serum TSH before FNA to assess functional status, though thyroid function tests have limited value for malignancy assessment since most thyroid cancers present with normal thyroid function. 1, 7

• If TSH is suppressed, obtain a radionuclide thyroid scan before FNA, as hyperfunctioning nodules are rarely malignant and may not require biopsy. 4

Critical Considerations About the Symptom

• "Tightness" is a nonspecific symptom that could represent true nodule enlargement causing compression, degenerative changes within the nodule (which can mimic malignant features on ultrasound), or unrelated musculoskeletal/anxiety-related sensations. 8

• Degenerating nodules can cause acute symptoms and demonstrate suspicious ultrasound features (hypoechogenicity, irregular margins) that mimic malignancy, making serial ultrasound follow-up essential to distinguish true growth from degenerative changes. 8

• Do not dismiss the patient's concern, as approximately 10% of thyroid nodules harbor clinically significant cancer, and symptoms may indicate interval change requiring evaluation. 6

Common Pitfalls to Avoid

• Do not rely on palpation alone to assess interval change, as ultrasound is far more sensitive for detecting growth in small nodules. 6, 3

• Do not perform FNA on nodules <1 cm without high-risk features, as this leads to overdiagnosis and overtreatment of clinically insignificant papillary microcarcinomas (<1 cm) that carry excellent long-term prognosis. 1, 2

• Do not order thyroglobulin levels as part of the diagnostic workup, as this test is of little help in diagnosing thyroid cancer in patients with intact thyroid glands. 1

• Consider measuring serum calcitonin as part of the evaluation to screen for medullary thyroid cancer (5-7% of thyroid cancers), which has higher sensitivity than FNA alone for this specific malignancy. 1, 7

Follow-Up Strategy Based on Ultrasound Results

• If repeat ultrasound shows benign features and no growth, resume surveillance with ultrasound at 12-24 month intervals rather than another 4-year gap. 3, 4

• If FNA is performed and yields benign cytology (Bethesda II), the risk of malignancy is very low (1-3%), and continued surveillance is appropriate. 2

• If FNA yields indeterminate results (Bethesda III or IV), consider molecular testing (BRAF, RAS, RET/PTC, PAX8/PPARγ) or repeat FNA to guide management decisions between surgery and observation. 2, 7, 4