endocrine and metabolic disorders
Cushing Syndrome
Etiology of Cushing Syndrome
Hyperfunction of the adrenal cortex can be adrenocorticotropic hormone (ACTH)-dependent or ACTH-independent. ACTH-dependent hyperfunctionmay result from Hypersecretion of ACTH by the pituitary gland (Cushing disease) Secretion of ACTH by a nonpituitary tumor, such as Classification or a Administration of exogenous ACTH ACTH-independent hyperfunctionusually results from Therapeutic administration of corticosteroids Adrenal adenomas or carcinomas Rare causes of ACTH-independent hyperfunction include primary pigmented nodular adrenal dysplasia (usually in adolescents) and bilateral macronodular hyperplasia (in older patients). Whereas the term Cushing syndrome denotes the clinical picture resulting from corticosteroid excess from any cause, Cushing disease refers to hyperfunction of the adrenal cortex from pituitary ACTH excess. Patients with Cushing disease almost always have a small Pituitary Lesions . 