Thyroglobulin
Thyroglobulin is a thyroid protein used as a marker for thyroid function and cancer recurrence, particularly after thyroidectomy.
About This Biomarker
Why We Test This
What Affects It
How to Improve
Understanding Your Results (ng/mL)
Low
(< 1 ng/mL)
Very low or undetectable thyroglobulin levels are expected in individuals without a thyroid gland (post-thyroidectomy) or in those with minimal thyroid tissue. In these cases, low levels suggest that there is no residual thyroid tissue or cancer. However, in the presence of thyroglobulin antibodies, low levels might need further evaluation to rule out interference in the test results.
Optimal
(1 - 40 ng/mL)
Normal thyroglobulin levels generally indicate no active thyroid disease or cancer recurrence, particularly in the context of thyroid cancer surveillance. It suggests that the thyroid gland is functioning properly and that there is no significant thyroid tissue producing excess thyroglobulin.
Thyroglobulin levels near the upper limit might suggest mild thyroid dysfunction or an early stage of thyroid disease. In cancer patients, this could indicate a need for closer monitoring, although it might not immediately suggest recurrence. Continuous monitoring and further evaluation, such as imaging or additional tests, may be necessary to assess the significance of these levels.
Thyroglobulin levels near the lower limit are often seen in individuals with a healthy thyroid or in those who have undergone successful thyroidectomy and radioactive iodine treatment, where minimal or no thyroid tissue remains. This is typically a good sign, particularly in cancer surveillance, indicating effective treatment.
High
(> 40 ng/mL)
Elevated thyroglobulin levels may indicate the presence of residual or recurrent thyroid cancer, especially after thyroidectomy and radioactive iodine therapy. In individuals with an intact thyroid, high thyroglobulin levels might suggest thyroid inflammation, hyperthyroidism, or a benign thyroid condition like a goiter. It's essential to interpret high thyroglobulin levels in the context of other clinical findings and tests.
Also known as: Tg