Patient Preparation: Overnight fasting is preferred.
Preferred Specimen(s): 1 mL serum
Minimum Volume: 0.5 mL
Specimen Container: Plastic screw-cap vial
Transport Temperature: Frozen
Specimen Stability
- Room temperature: unacceptable;
- refrigerated 24 hours;
- Frozen 28 days
Methodology: Immunoassay
Limitations: Basal concentrations of >100 pg/mL have been found to have 100% positive predictive value for medullary thyroid cancer. Lower concentrations may be observed in some patients with clinically apparent medullary thyroid cancer.
Clinical Significance: Calcitonin concentration is increased in patients with medullary thyroid carcinoma. Calcitonin concentrations may be used to monitor disease.