Hypercalcitoninemia is not Pathognomonic of Medullary Thyroid Carcinoma

• Published in: Clinics (São Paulo, Brazil) Vol. 64; no. 7; pp. 699 - 706
• Main Authors: Toledo, Sergio PA, Lourenço, Delmar M, Santos, Marcelo Augusto, Tavares, Marcos R, Toledo, Rodrigo A, de Menezes Correia-Deur, Joya Emilie
• Format: Journal Article
• Language: English
• Published: Brazil Elsevier España, S.L.U 01.01.2009; Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo; Faculdade de Medicina / USP; Elsevier España
• Subjects: Biomarkers, Tumor - blood; Calcitonin; Calcitonin - blood; Carcinoma, Medullary - blood; Carcinoma, Medullary - diagnosis; Carcinoma, Medullary - surgery; Diagnosis, Differential; False-positive test; Female; Humans; Male; MEDICINE, GENERAL & INTERNAL; Multiple Endocrine Neoplasia - blood; Multiple Endocrine Neoplasia - diagnosis; RET mutation; Review; Risk; Thyroid Neoplasms - blood; Thyroid Neoplasms - diagnosis; Thyroid Neoplasms - surgery; Thyroidectomy; Total thyroidectomy; RET mutation; Calcitonin; Total thyroidectomy; False-positive test
• ISSN: 1807-5932; 1980-5322; 1980-5322
• DOI: 10.1590/S1807-59322009000700015

Hypercalcitoninemia has frequently been reported as a marker for medullary thyroid carcinoma. Currently, calcitonin measurements are mostly useful in the evaluation of tumor size and progression, and as an index of biochemical improvement of medullary thyroid carcinomas. Although measurement of calcitonin is a highly sensitive method for the detection of medullary thyroid carcinoma, it presents a low specificity for this tumor. Several physiologic and pathologic conditions other than medullary thyroid carcinoma have been associated with increased levels of calcitonin. Several cases of thyroid nodules associated with increased values of calcitonin are not medullary thyroid carcinomas, but rather are related to other conditions, such as hypercalcemias, hypergastrinemias, neuroendocrine tumors, renal insufficiency, papillary and follicular thyroid carcinomas, and goiter. Furthermore, prolonged treatment with omeprazole (> 2–4 months), beta-blockers, glucocorticoids and potential secretagogues, have been associated with hypercalcitoninemia. An association between calcitonin levels and chronic auto-immune thyroiditis remains controversial. Patients with calcitonin levels >100 pg/mL have a high risk for medullary thyroid carcinoma (~90%–100%), whereas patients with values from 10 to 100 pg/mL (normal values: <8.5 pg/mL for men, < 5.0 pg/mL for women; immunochemiluminometric assay) have a <25% risk for medullary thyroid carcinoma. In multiple endocrine neoplasia type 2 (MEN2), RET mutation analysis is the gold-standard for the recommendation of total preventive thyroidectomy to relatives at risk of harboring a germline RET mutation (50%). False-positive calcitonin results within MEN2 families have led to incorrect indications of preventive total thyroidectomy to RET mutation negative relatives. In this review, we focus on the differential diagnosis of hypercalcitoninemia, underlining its importance for the avoidance of misdiagnosis of medullary thyroid carcinoma and consequent incorrect recommendation for thyroid surgery.