NODULE FEATURES | THRESHOLD SIZE FOR FNA | LIKELIHOOD OF MALIGNANCY |
---|---|---|
High suspicion | ≥ 1.0 cm | > 70%–90% |
Solid hypoechoic nodule or solid hypoechoic component of partially cystic nodule with ≥ 1 of the following features:
| ||
Intermediate suspicion | ≥ 1.0 cm | 10%–20% |
Hypoechoic solid nodule with smooth margin without the following:
| ||
Low suspicion | ≥ 1.5 cm | 5%–10% |
Isoechoic or hyperechoic solid nodule, or partially cystic nodule with eccentric solid area without any ultrasonographic features | ||
Very low suspicion | ≥ 2.0 cm | < 3% |
Spongiform or partially cystic without any ultrasonographic features | ||
Purely cystic nodules | No biopsy required | < 1% |
FNA—fine-needle aspiration.