Test Directory

Detection and confirmation C-cell hyperplasia (the precursor of medullary carcinoma of thyroid) as well as a tumor marker for diagnosis and management of medullary carcinoma of the thyroid gland. Preoperative serum calcitonin is reported to roughly correlate with tumor weight or extent of disease; therefore, postoperative levels also have prognostic application. The doubling time of serum levels correlates with a recurrence. Multiple endocrine neoplasia (MEN) type II includes medullary carcinoma of the thyroid, hyperparathyroidism, and pheochromocytoma (Sipple syndrome). MEN type IIB includes medullary carcinoma of the thyroid, pheochromocytoma, mucosal neuromas, marfanoid habitus, and intestinal ganglioneuromatosis. An important use of calcitonin assay is in follow-up of patients with medullary carcinoma and work-up of their families to detect early, subclinical cases. Indications for calcitonin assay include family history of unspecified type of thyroid cancer, calcified thyroid mass, thyroid tumor associated with hypercalcemia and/or pheochromocytoma, amyloid-containing metastatic carcinoma with unknown primary site and the presence of mucosal neuromas.

Specimen Type: Serum

Collection Container: Gold Top, Serum Separator

Alternate Collection Container: Red Top, Plain

Desired Specimen Volume: 1 mL

1. Collect serum separator tube via venipuncture

1. Separate serum from cells.
2. Transfer 1 mL of serum to a LabCorp PP transpak frozen purple tube.
3. Freeze immediately and maintain frozen until tested
4. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.

 Patient should be fasting.

Transport to the laboratory frozen. 

• Gross hemolysis
• Specimen not received frozen
• Lipemia
• Plasma specimen

See patient report.

In a number of patients with medullary carcinoma of the thyroid (especially those with familial medullary carcinoma of thyroid) the baseline calcitonin may be normal; however, an abnormally large calcitonin response may follow provocative infusion of calcium and/or pentagastrin (usually 3 to 20 times baseline). Most subjects with microscopic medullary carcinoma and all with C-cell hyperplasia have normal basal calcitonin levels; provocative testing is needed (see the online Endocrine Appendix: Calcium-Pentagastrin Stimulation). Occasional spurious high results are encountered. Hemolysis can cause spurious high levels. Calcitonin in patients' sera lacks immunoreactive uniformity. Calcitonin is not a screening test.

Values obtained with different assay methods should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor each patient's course of therapy. This procedure does not provide serial monitoring; it is intended for one-time use only.

• Thyrocalcitonin