TSH assay is the best parameter of the thyroid function. For adults, the normal interval of TSH concentrations range from 0.4 to 4 mUI/L. At the first trimester of pregnancy, TSH levels must be <2.5 mUI/L. Normal TSH levels increase with aging and
obesity. 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 is a reliable measure of integrated GH concentrations in patients with
acromegaly. Accurate assessment of IGF1 concentrations requires age and sex-matched control values. IGF1 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 "incipiens" 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.