The Duke 3-tiered system for CT, MRI, or PET-detected thyroid nodules1,13,14,a
| Category | Criteria for Categories | Recommendations |
|---|---|---|
| Risk category 1: highly suspicious for malignancy | PET avid thyroid nodule | Strongly consider work-up with ultrasound for any size nodule |
| Suspicious lymphadenopathy;b extrathyroid spread with or without signs of vocal cord palsy on side of nodule; lung metastases | ||
| Risk category 2: indeterminate with risk factor of young age | Age younger than 35 years | Consider work-up with ultrasound if ≥1 cm in adults |
| Consider work-up with ultrasound for any size in pediatric patients | ||
| Risk category 3: indeterminate without risk factors | Age 35 years or older | Consider work-up with ultrasound if ≥1.5 cm |
↵a Intended for management of incidental thyroid nodules in low-risk patients.
↵b Suspicious lymph nodes are defined as nodes >10 mm in the short axis (with the exception of jugulodigastric lymph nodes, which are permitted to be up to 15 mm in the short axis) or nodes that contain either calcifications, cystic components, or irregular margins.