title: Spuriously elevated plasma calcitonin in a patient with a thyroid nodule not associated with medullary thyroid carcinoma.
abstract: An increase in plasma calcitonin concentration is widely regarded as a specific and sensitive indication of underlying medullary thyroid carcinoma (MTC). We present a case in which the association of increased plasma calcitonin concentration and a thyroid nodule was not due to MTC. Subsequent measurement of plasma calcitonin by a variety of methods highlighted the variability that exists in calcitonin measurement and the potential for clinically misleading results. The rationale for investigation and treatment of MTC, including a recommendation to screen all patients with thyroid nodules using plasma calcitonin measurement, is based on the use of specific two-site calcitonin assays which are not universally used in the UK or USA.
authors.affiliation: Department of Clinical Biochemistry, Kent Hospital NHS Trust, UK.
authors.forename: E J
authors.initials: EJ
authors.lastname: Lamb
authors.forename: R M
authors.initials: RM
authors.lastname: Heddle
authors.forename: A
authors.initials: A
authors.lastname: Ellis
mesh_terms: D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011863:Radioimmunoassay; D012016:Reference Values; D013964:Thyroid Neoplasms / Q000097:blood* / Q000601:surgery; D016606:Thyroid Nodule / Q000097:blood* / Q000601:surgery
chemical_list: D015415:Biomarkers; D002116:Calcitonin