Description:

Formal name: Thyroglobulin (Tg)
Related tests: Thyroglobulin antibody, Tumor markers , TSH, Thyroxine (T4)
Why get tested?
To monitor treatment of some types of thyroid cancer and to detect recurrence; less commonly, may be used to help determine the cause of hyperthyroidism

When to get tested?
Prior to and after the completion of treatment for thyroid cancer, before and after radioactive iodine therapy, and at regular intervals to monitor for recurrence

What is being tested?
This test measures the amount of thyroglobulin in the blood. Thyroglobulin is a protein produced by follicle cells in the thyroid gland. The thyroid gland is a small butterfly-shaped organ that helps to regulate the rate at which the body uses energy. The thyroid lies flat against the windpipe in the throat and is composed primarily of very small, ball-shaped structures called follicles. Cells in the follicles produce and store thyroglobulin, breaking it down as needed into the thyroid hormones T4 (thyroxine) and T3 (triiodothyronine). The production of these hormones and their release into the blood stream is stimulated by the pituitary hormone TSH (thyroid stimulating hormone). No other part of the body makes thyroglobulin, but it is produced by many thyroid cancers – both those confined to the thyroid gland and those that have spread to other parts of the body.