Ultrasonographic Pattern

Ultrasonographic Characteristics

Estimated Risk of Malignancy

FNA Size Cutoff (largest dimension)

High suspicion

Solid hypoechoic nodule or solid hypoechoic component of a partially cystic nodule with one or more of the following features: irregular margins (infiltrative, microlobulated), microcalcifications, taller than wide shape, rim calcifications with small extrusive soft tissue component, evidence of extra thyroid extension (ETE)

Greater than 70% - 90%

FNA at equal or greater than 1 cm

Intermediate suspicion

Hypoechoic solid nodule with smooth margins without microcalcifications, ETE, or taller than wide shape

10% al 20%

FNA at equal or greater than 1 cm

Low suspicion

Isoechoic or hyperechoic solid nodule, or partially cystic nodule with eccentric solid areas, without microcalcification, irregular margin or ETE, or taller than wide shape

5% al 10%

FNA at equal or greater than 1.5 cm

Very low suspicion

Spongiform or partially cystic nodules without any of the sonographic features described in low, intermediate, or high suspicion patterns

Less than 3%

Consider FNA at equal or greater 2 cm

Observation without FNA is also an option


Purely cystic nodules (no solid component)

Less than 1%

No biopsy