The biological diagnosis relies on the identification of excessive secretion of the metanephrines which are more sensitive and specific than those of catecholamines. The concentrations of the free plasmatic metanephrines reflect the ongoing production of tumor. Plasma methoxytyramine is a novel biomarker of metastatic pheochromocytomas and paragangliomas.
Serum IGF1聽is a reliable measure of integrated GH concentrations in patients with acromegaly. Accurate assessment of IGF1聽concentrations requires age and sex-matched control values. IGF1聽is a sensitive tool for the diagnosis of acromegaly and efficacy of therapies.
Serum AMH assay is more sensitive, more specific and more reproducible that counting of ovarian follicles by ultrasound. AMH level above 5 ng/mL (35 pmol/L) could be chosen as one of the diagnostic criteria for the polycystic ovary syndrome. In early or 鈥渋ncipiens鈥?ovarian failure, the decrease in serum AMH is far ahead of the increase in FSH.
Thyroglobulin (TG) and calcitonin (CT) are the sensitive and specific markers of respectively well-differentiated thyroid cancers of follicular origin and of the medullary thyroid cancers. The same tumour marker assay should be used to monitor a given patient.
Chromogranin A (CgA) is a highly efficient biomarker for diagnosis and follow-up of various endocrine tumours. Despite the lack of international standardisation, some CgA assays are reliable.