Order Code: THYCA
Referral Laboratory: Quest
Effective March 25, 2020, Thyroid Cancer Monitoring (THYCA) is down until further notice per Quest.
Thyroglobulin and Thyroglobulin Antibody
Order Code: THYRG
CPT Code: 84432, 86800
Thyroglobulin Mass Spectrometry
Order Code: TGMS
CPT Code: 84432
Referral Laboratory: Mayo Medical Laboratories
Test Usage: The recommended first test to order for monitoring thyroglobulin concentrations in patients with thyroid neoplasia is Thyroglobulin (TG) + Thyroglobulin Antibody (anti-TG) (order code THYRG). If antibody is negative, then the immunoassay measurement of Thyroglobulin (included in this test) is sufficiently sensitive for monitoring purposes. If Thyroglobulin antibodies are present, then Thyroglobulin measurement by Mass Spectrometry (LC/MS) is warranted (order code TGMS forwarded to Mayo Clinic Laboratories).
Note that there are occasional patients in whom clinical setting suggests that Thyroglobulin “should” be detectable by LC/MS but is not. There is some evidence that TG-Anti-TG complexes are being rapidly cleared. In these patients it may be useful to follow anti-TG antibody levels.