Management of Multiple Thyroid Nodules Post-Hemithyroidectomy

Immediate Management of TR 4 Nodules

The American College of Radiology (ACR) recommends fine-needle aspiration (FNA) for TR 4 nodules if they are ≥1.5 cm, and surveillance if they are ≥1 cm, with ultrasound follow-up at years 1, 2, 3, and 5 1
For TR 4 nodules measuring ≥1.0 cm, initiate ultrasound surveillance at years 1, 2, 3, and 5, and for those measuring ≥1.5 cm, proceed directly to FNA 1
If all TR 4 nodules are truly <1.0 cm, no immediate action is required, but monitor for growth 1

The ACR TI-RADS threshold for TR 3 nodules is ≥2.5 cm for biopsy, and the recommended surveillance interval is years 1, 3, and 5 1
For the growing TR 3 nodule at 1.4 cm, follow-up with ultrasound at years 1, 3, and 5, without immediate FNA, as it remains below the 2.5 cm threshold for biopsy 1

Measure serum TSH immediately if not already done, as it is the single best initial test of thyroid function and significantly impacts management, with elevated TSH (>1.64 mU/L) substantially increasing malignancy risk in nodular disease 1, 2, 3
Perform ultrasound evaluation of lateral neck lymph nodes, given the history of hemithyroidectomy and multiple nodules, as associated lymphadenopathy is a high-risk feature that would alter management regardless of nodule size 1, 3

For the patient with prior hemithyroidectomy, the remaining thyroid lobe requires lifelong surveillance given the increased baseline risk, with annual TSH measurement and less intensive protocols for very low suspicion nodules that remain stable for 5 years 1, 2, 4