Table 2.
EU-TIRADS categories and risk of malignancy
| Category | US features | Malignancy risk, % |
|---|---|---|
| EU-TIRADS 1: normal | No nodules | None |
| EU-TIRADS 2: benign | Pure cyst Entirely spongiform |
$0 |
| EU-TIRADS 3: low risk | Ovoid, smooth isoechoic/hyperechoic No features of high suspicion |
2–4 |
| EU-TIRADS 4: intermediate risk | Ovoid, smooth, mildly hypoechoic No features of high suspicion |
6–17 |
| EU-TIRADS 5: high risk | At least 1 of the following features of high suspicion: | 26–87 |
| − Irregular shape | ||
| − Irregular margins | ||
| − Microcalcifications | ||
| − Marked hypoechogenicity (and solid) | ||
EU-TIRADS, European Thyroid Imaging Reporting and Data System; US, ultrasound.