Adrenal Neoplasms

The adrenal glands are chiefly responsible for releasing hormones in response to stress through the synthesis of corticosteroids such as cortisol and catecholamines such as epinephrine, and in response to plasma osmolarity changes through the secretion of aldosterone. The adrenal cortex is divided into functional zones, including zona glomerulosa, zona fasciculata, and zona reticularis. The outermost layer, the zona glomerulosa, is the main site for production of mineralocorticoids, mainly aldosterone, which is largely responsible for the long-term regulation of blood pressure by affecting the functions of the kidneys. The innermost cortical layer, the zona reticularis, produces androgens, mainly dehydroepiandrosterone and dehydroepiandrosterone sulfate. Situated between the glomerulosa and reticularis, the zona fasciculata is responsible for producing glucocorticoids, chiefly cortisol. Whereas the zona glomerulosa is primarily regulated by angiotensin II, both the zona fasciculata and the zona reticularis are regulated by corticotropin or adrenocorticotropic hormone. Both these zones become hypofunctional and atrophic when adrenocorticotropic hormone is deficient; on the other hand, they become hypertrophic and hyperplastic when adrenocorticotropic hormone is secreted in excess.