U/S can be used to risk-stratify using the Thyroid Imaging Reporting and Data System (TI-RADS) (http://tiradscalculator.com/)
Solid nodule
- With suspicious sonographic features >1.0 cm
- Without suspicious sonographic features >1.5 cm
Mixed cystic-solid nodule
- With suspicious sonographic features: hypoechoic,
microcalcifications, infiltrative margins, taller
than wide in transverse plane Solid component >1.0 cm - Without suspicious sonographic features: Spongiform
nodules, isoechoic of hyperechoic solid nodules, mixed
solid-cystic nodules without above suspicious features Solid component >1.5 cm
Spongiform nodule (multiple microcystic components
in >50% of volume of nodule >2.0 cm
Suspicious cervical lymph node: FNAC of node +/- thyroid nodule
If FNAC not indicated, then repeat US after 6-12 months; if stable for 1-2yrs, then consider US at 3-5 yearly intervals
Above criteria are general guidelines: With high risk clinical features, evaluation of smaller nodules may be indicated based on clinical concerns e.g. prior thyroid cancer, radiation exposure, 1st degree relative with thyroid cancer of MEN2, FDG avid on PET scan, thyroid cancer associated history e.g. familial adenomatous polyposis, Carney complex, Cowden syndrome
African Head & Neck Society (AfHNS) Clinical Practice Guidelines for Head & Neck Cancers in Developing Countries and Limited Resource Settings 