Evaluation and Management of Palpable Thyroid Nodules

Initial Evaluation Algorithm

The American College of Radiology recommends that all palpable thyroid nodules should be evaluated with thyroid function tests (TSH) first, followed by ultrasound, with fine-needle aspiration biopsy (FNAB) recommended for nodules ≥1 cm or smaller nodules with suspicious features 1, 2
Thyroid function tests, particularly TSH, should be the first laboratory test for any patient with a thyroid nodule, as TSH results will guide subsequent management approach 1, 2

If TSH is low, perform ultrasound to evaluate thyroid morphology, and follow with radionuclide thyroid uptake scan to determine if the nodule is hyperfunctioning, as hyperfunctioning ("hot") nodules rarely require biopsy due to low malignancy risk 1, 2, 3
If TSH is normal or elevated, proceed directly to ultrasound evaluation, which provides high-resolution imaging to confirm the nodule is within the thyroid and characterize malignancy risk 1, 2, 3

Ultrasound features suspicious for malignancy include hypoechogenicity, microcalcifications, absence of peripheral halo, irregular borders, solid composition, intranodular blood flow, and taller-than-wide shape 4, 5, 6

FNAB should be performed for any thyroid nodule >1 cm, or nodules <1 cm with suspicious clinical features or suspicious ultrasound features, with ultrasound guidance improving accuracy of FNAB 4, 5, 6

The American College of Surgeons recommends evaluation of thyroid nodules larger than 2 cm, even without suspicious features, due to increased malignancy risk 6
For indeterminate cytology results, consider surgery when TSH is normal and the nodule appears "cold" on thyroid scan, and molecular testing may help differentiate benign from malignant nodules in indeterminate cases 4, 5

Proceeding directly to radionuclide scan without first checking TSH levels, and using radionuclide scanning to determine malignancy in euthyroid patients, which has low positive predictive value 1, 3

For benign nodules (Bethesda category II), the risk of malignancy is very low (1-3%), and most thyroid nodules do not require treatment 6