thyroglobulin
A protein produced by thyroid follicular cells that serves as a precursor for thyroid hormone synthesis and a tumor marker.
Full Definition
Thyroglobulin is a large glycoprotein synthesized and stored in thyroid follicular cells, serving as the precursor molecule for thyroid hormone production. During hormone synthesis, thyroglobulin undergoes iodination and coupling reactions to form thyroxine (T4) and triiodothyronine (T3). In pediatric endocrinology, serum thyroglobulin levels are primarily used as a tumor marker following thyroidectomy for thyroid cancer, as well as to monitor treatment response. Elevated thyroglobulin levels may indicate thyroid inflammation, hyperfunction, or malignancy. The interpretation of thyroglobulin levels requires consideration of thyroid-stimulating hormone status and the presence of thyroglobulin antibodies.
Usage
Usage note: Distinguish from thyroglobulin antibodies, which interfere with measurement.
In Context
- "Post-surgical thyroglobulin levels remained undetectable, indicating complete thyroid tissue removal." — Oncology follow-up
- "Elevated thyroglobulin with suppressed TSH suggested autonomous thyroid function." — Thyroid function assessment