Defect | Radionuclide image | Ultrasonography | Serum thyroglobulin | Maternal TRB-Ab |
---|---|---|---|---|
Aplasia | No uptake | Absent gland | Low | Negative |
Hypoplasia | ↓ uptake | Small, eutopic | Intermediate | Negative |
Ectopia | ↓ uptake, ectopic | Ectopic gland (hypoplastic) | Intermediate | Negative |
TSHβ mutations | No uptake | Eutopic gland (hypoplastic) | Intermediate | Negative |
TSH receptor inactivating mutation | ↓ uptake | Eutopic gland | Intermediate-high | Negative |
Trapping error | ↓ or no uptake | Eutopic gland | Low-intermediate | Negative |
Beyond trapping error | ↑ uptake | Eutopic, large gland | High Exception: Tg gene mutations | Negative |
Maternal TRB-Ab | ↓ or no uptake | Eutopic gland | Low-intermediate | Positive |