Adrenal disorders
| Adrenal insufficiency | |
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| Adrenal gland |
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Adrenal disorders Main Page |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Usama Talib, BSc, MD [2] Mehrian Jafarizade, M.D [3]
Overview
Adrenal or suprarenal glands are important endocrine glands that produce variety of hormones such as epinephrine, steroids, aldosterone and cortisol. Each gland consists of an outer capsule and underneath cortex, and the central part called medulla. The cortex is further classified into thee layers, and each layer produces specific hormone. Congenital adrenal hyperplasia is the disease of adrenal cortex which is classified into seven types based on the genetic causes that lead to hyperplasia and hormonal imbalance. There are three zones of hormonal synthesis in the adrenal cortex; zona glumerulosa is responsible for aldosterone synthesis; zona fasciculate for cortisol synthesis and zona reticularis for androgen synthesis. Impairment of each pathway and enzyme may lead to a specific subtype of congenital adrenal hyperplasia such as 21-hydroxylase deficiency, 17 alpha-hydroxylase deficiency, 11β-hydroxylase deficiency, 3 beta-hydroxysteroid dehydrogenase deficiency, cytochrome P450-oxidoreductase (POR) deficiency (ORD), and congenital lipoid adrenal hyperplasia. Other adrenal cortex disease are hyperaldosteronism due to zona glumerulosa hyperplasia, and Cushing's syndrome due to zona fasciculate disease. Pheochromocytoma is a neuroendocrine tumor of the medullary part of the adrenal glands, which fails to involute after birth. They secrete excessive amount of catecholamines, mostly epinephrine and norepinephrine. Incidentaloma is another adrenal tumor that often discovered as an incidental finding in ultrasonography. Most incidentalomas are nonfunctional but some of them are found to secrete low levels of cortisol, aldosterone or catecholamines.
Classification