Normal Reference Ranges
Adult
3 - 40 ng/mL
Pediatric
3 - 40 ng/mL
Clinical Significance
Protein synthesized exclusively by follicular thyroid cells. Primarily used as a tumor marker to monitor for recurrence of differentiated thyroid cancer following thyroidectomy.
Causes of High
- Graves' disease
- Subacute thyroiditis
- Differentiated thyroid cancer (papillary/follicular)
Causes of Low
- Thyroidectomy
- Factitious thyrotoxicosis (exogenous thyroid hormone ingestion)