From the Research
For a 2-cm thyroid mass with normal TSH in an asymptomatic patient, I recommend obtaining a thyroid ultrasound followed by fine-needle aspiration (FNA) biopsy, as this approach is supported by the most recent and highest quality study 1. The ultrasound will characterize the nodule's features (solid vs. cystic, echogenicity, margins, calcifications, vascularity) which help determine malignancy risk. Any nodule ≥1.5 cm should generally undergo FNA biopsy to rule out cancer, even with normal thyroid function. After initial evaluation, follow-up should include:
- Repeat ultrasound in 6-12 months to assess for growth
- Subsequent ultrasounds annually for 3-5 years if stable If the FNA is benign, continued surveillance is still necessary as approximately 5% of benign-appearing nodules may be falsely negative. TSH should be rechecked annually. If the nodule grows significantly (>20% increase with minimum 2mm increase in two dimensions), shows suspicious ultrasound changes, or if the patient develops symptoms like difficulty swallowing, voice changes, or neck discomfort, repeat FNA or surgical consultation may be warranted. This approach balances the need to identify potential malignancy while avoiding unnecessary procedures for what are most commonly benign thyroid nodules, as supported by recent studies 2, 1.
Key considerations in the follow-up protocol include:
- The risk of malignancy, which is estimated to be around 10% for thyroid nodules 3
- The presence and severity of compressive symptoms, which may require more frequent follow-up or intervention 3
- The results of the initial FNA biopsy, which may guide the need for further testing or treatment 4, 5
- The patient's overall health status and preferences, which should be taken into account when determining the frequency and duration of follow-up 1