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HelpTest ID: CATN Calcitonin, Serum
Reporting Name
Calcitonin, SUseful For
Aids in the diagnosis and follow-up of medullary thyroid carcinoma
Aids in the evaluation of multiple endocrine neoplasia type II and familial medullary thyroid carcinoma
This test is not useful for evaluating calcium metabolic diseases.
Clinical Information
Calcitonin is a polypeptide hormone secreted by the parafollicular cells (also referred to as calcitonin cells or C cells) of the thyroid gland. The main action of calcitonin is the inhibition of bone resorption by regulating the number and activity of osteoclasts. Calcitonin is secreted in direct response to serum hypercalcemia and may prevent large oscillations in serum calcium levels and excessive loss of body calcium. However, in comparison to parathyroid hormone and 1,25-dihydroxyvitamin D, the role of calcitonin in the regulation of serum calcium in humans is minor. Measurements of serum calcitonin levels are, therefore, not useful in the diagnosis of disorders of calcium homeostasis.
Malignant tumors arising from thyroid C cells (medullary thyroid carcinoma: MTC) usually produce elevated levels of calcitonin. MTC is an uncommon malignant thyroid tumor, comprising less than 5% of all thyroid malignancies. Approximately 25% of these are familial cases, usually appearing as a component of multiple endocrine neoplasia type II (MENII, Sipple syndrome). MTC may also occur in families without other associated endocrine dysfunction, with similar autosomal dominant transmission as MENII, which is then called familial medullary thyroid carcinoma (FMTC). Variants in the RET proto-oncogene are associated with MENII and FMTC.
Serum calcitonin concentrations are high in infants, decline rapidly, and are relatively stable from childhood through adulthood. In general, calcitonin serum concentrations are higher in men than in women due to the larger C-cell mass in men. Serum calcitonin concentrations may be increased in patients with chronic kidney failure, and other conditions such as hyperparathyroidism, leukemic and myeloproliferative disorders, Zollinger-Ellison syndrome, autoimmune thyroiditis, small cell and large cell lung cancers, breast and prostate cancer, mastocytosis, and various neuroendocrine tumors, in particular, islet cell tumors.
Interpretation
Although most patients with sporadic medullary thyroid carcinoma (MTC) have high basal serum calcitonin concentrations, 30% of those with familial MTC or multiple endocrine neoplasia type II have normal basal levels.
In completely cured cases following surgical therapy for MTC, serum calcitonin levels fall into the undetectable range over a variable period of several weeks. Persistently elevated postoperative serum calcitonin levels usually indicate incomplete cure. The reasons for this can be locoregional lymph node spread or distant metastases. In most of these cases, imaging procedures are required for further workup. Those individuals who are then found to suffer only locoregional spread may benefit from additional surgical procedures. However, the survival benefits derived from such approaches are still debated.
A rise in previously undetectable or very low postoperative serum calcitonin levels is highly suggestive of disease recurrence or spread and should trigger further diagnostic evaluations.
Report Available
1 to 3 daysDay(s) Performed
Monday through Saturday
Clinical Reference
1. Wells SA Jr, Asa SL, Dralle H, et al. Revised American Thyroid Association guidelines for the management of medullary thyroid carcinoma. Thyroid. 2015;25(6):567-610
2. Griebeler ML, Gharib H, Thompson GB. Medullary thyroid carcinoma. Endocr Pract. 2013;19(4):703-711
3. Richards ML. Familial syndromes associated with thyroid cancer in the era of personalized medicine. Thyroid. 2010;20(7):707-713
Method Name
Electrochemiluminescence Immunoassay
Specimen Type
SerumSpecimen Required
Patient Preparation: For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements (eg, hair, skin, and nail supplements) containing biotin (vitamin B7).
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. After collection, immediately place specimen on ice.
2. Refrigerate specimen during centrifugation and immediately transfer serum to a plastic vial.
Specimen Minimum Volume
0.75 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen (preferred) | 90 days | |
| Refrigerated | 24 hours | ||
| Ambient | 8 hours |
Reference Values
Pediatric
1 month: ≤34 pg/mL
2 months: ≤31 pg/mL
3 months: ≤28 pg/mL
4 months: ≤26 pg/mL
5 months: ≤24 pg/mL
6 months: ≤22 pg/mL
7 months: ≤20 pg/mL
8 months: ≤19.0 pg/mL
9 months: ≤17.0 pg/mL
10 months: ≤16.0 pg/mL
11 months: ≤15.0 pg/mL
12-14 months: ≤14.0 pg/mL
15-17 months: ≤12.0 pg/mL
18-20 months: ≤10.0 pg/mL
21-23 months: ≤9.0 pg/mL
2 years: ≤8.0 pg/mL
3-9 years: ≤7.0 pg/mL
10-15 years: ≤6.0 pg/mL
16 years: ≤5.0 pg/mL
Adults
17 years and older:
Males: ≤14.3 pg/mL
Females: ≤7.6 pg/mL
For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
82308
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CATN | Calcitonin, S | 1992-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| CATN | Calcitonin, S | 1992-7 |
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
mml-endo-thyroid, mml-adrenal-gonad-pituitary