CPT® Code 84432

The CPT® Code 84432 refers to the laboratory test for measuring thyroglobulin (Tg) levels in the blood or fine needle aspirate (FNA) fluid. Thyroglobulin is a protein synthesized by the thyroid gland, serving as a precursor for the synthesis of the two primary thyroid hormones: thyroxine (T4) and triiodothyronine (T3). This test is significant in the evaluation of thyroid function and pathology, particularly in the context of thyroid cancer and autoimmune thyroid diseases. Elevated levels of thyroglobulin in the bloodstream may indicate the presence of certain thyroid conditions, including papillary or follicular thyroid cancer, as well as Hashimoto's thyroiditis, which is also known as Grave's disease. It is important to note that this test is frequently ordered alongside the thyroglobulin antibody test (CPT® Code 86800), as the presence of thyroglobulin antibodies (TgAb) can potentially interfere with the accuracy of the thyroglobulin test results. The collection of a blood sample for this test is performed through a procedure known as venipuncture, which is reportable separately. Additionally, if thyroid cells are needed for analysis, they can be obtained via a fine needle aspiration (FNA), which is also reportable separately. The testing of serum or plasma, as well as FNA fluid, is conducted using a quantitative chemiluminescent immunoassay, a sensitive and specific method for measuring the concentration of thyroglobulin in the samples.