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.

Patient should be fasting

Gold serum separator (SST) tube

Immediately following collection, thoroughly mix sample by gently inverting 5 times

1. Allow sample to clot for a minimum of 30 minutes
2. Spin within two (2) hours of sample collection
3. Transfer serum to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as serum
4. Freeze

Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)

Red serum vial/tube, 5 mL

1. Allow sample to clot
2. Spin within two (2) hours of sample collection
3. Transfer serum to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as serum
4. Freeze

Frozen (strict) - 90 days

Freeze/thaw cycles - stable x 3

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

Immunochemiluminometric assay (ICMA)

Male:    0.0 - 8.4 pg/mL

Female: 0.0 - 5.0 pg/mL

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 intestinalganglioneuromatosis. 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.

High concentrations of calcitonin occur not only in patients with malignant parafollicular or C-cell tumors (medullary thyroid carcinoma), but also in many patients with carcinomas of the lung; in some individuals with carcinoma of breast, carcinoids, islet cell tumors, apudomas, in patients with pancreatitis, thyroiditis and in renal failure. Hypergastrinemia may account for calcitonin elevations in the Zollinger-Ellison syndrome and in pernicious anemia. Medullary carcinoma arises from thyroid C cells (parafollicular cells). C-cell hyperplasia is a preneoplastic state in patients with MEN. Provocative tests that may be used for diagnosis of medullary thyroid carcinoma are pentagastrin and calcium infusion. Acombined calcium pentagastrin test is described in the Endocrine Dynamic Testing Appendix. These tests are much more useful than random plasma levels of calcitonin for the diagnosis of MCT. Early diagnosis of medullary carcinoma of thyroid is needed; total thyroidectomy is curative if the tumor is treated early. Medullary carcinomas of the thyroid gland have a variable histologic picture. Correlation between serum calcitonin levels and immunoperoxidase staining of the neoplastic thyroid tissue for calcitonin may assist in confirming the diagnosis in difficult cases. The direct manifestation of high calcitonin levels is secretory diarrhea in 30% of patients with medullary thyroid carcinoma. This procedure does not provide serial monitoring; it is intended for one-time use only. Indicate if calcium infusion or pentagastrin injection tests are part of the patient preparation. 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.