Cushing's syndrome causes
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Furqan M M. M.B.B.S[2]
Overview
Cushing’s syndrome occurs when the body’s tissues are exposed to high levels of cortisol for a long period. Many people develop Cushing’s syndrome because they take glucocorticoids—steroid hormones that are chemically similar to naturally produced cortisol—such as prednisone for asthma, rheumatoid arthritis, lupus, and other inflammatory diseases. Glucocorticoids are also used to suppress the immune system after transplantation to keep the body from rejecting the new organ or tissue. Other people develop Cushing’s syndrome because their bodies produce too much cortisol from due to adrenal or extra-adrenal causes. Normally, the production of cortisol follows a precise chain of events. First, the hypothalamus, sends corticotropin-releasing hormone (CRH) to the pituitary gland. CRH causes the pituitary to secrete adrenocorticotropin hormone (ACTH), which stimulates the adrenal glands. When the adrenals, which are located just above the kidneys, receive the ACTH, they respond by releasing cortisol into the bloodstream.
Causes
The major causes of Cushing's syndrome are:[1][2][3]
- Excess ACTH sectretion
- Pituitary Adenomas:
These benign, or noncancerous, tumors of the pituitary gland secrete extra ACTH. Most people with the disorder have a single adenoma. This form of the syndrome, known as Cushing’s disease.
- Ectopic ACTH Syndrome:
Some benign or, more often, cancerous tumors that arise outside the pituitary can produce ACTH. This condition is known as ectopic ACTH syndrome. Lung tumors cause more than half of these cases.
- Excess secretion of cortisol by adrenal glands:
- Adrenal Tumors:
In rare cases, an abnormality of the adrenal glands, most often an adrenal tumor, causes Cushing’s syndrome. Adrenal tumors are four to five times more common in women than men, and the average age of onset is about 40. Most of these cases involve noncancerous tumors of adrenal tissue called adrenal adenomas, which release excess cortisol into the blood.
- Adrenocortical carcinomas—adrenal cancers:
These are the least common cause of Cushing’s syndrome. With adrenocortical carcinomas, cancer cells secrete excess levels of several adrenocortical hormones, including cortisol and adrenal androgens, a type of male hormone. Adrenocortical carcinomas usually cause very high hormone levels and rapid development of symptoms.
Familial Cushing’s Syndrome
Most cases of Cushing’s syndrome are not inherited. Rarely, however, Cushing’s syndrome results from an inherited tendency to develop tumors of one or more endocrine glands. Endocrine glands release hormones into the bloodstream. With primary pigmented micronodular adrenal disease, children or young adults develop small cortisol-producing tumors of the adrenal glands. With multiple endocrine neoplasia type 1 (MEN1), hormone-secreting tumors of the parathyroid glands, pancreas, and pituitary develop; Cushing’s syndrome in MEN1 may be due to pituitary, ectopic, or adrenal tumors.
Drugs
- Betamethasone dipropionate
- Betamethasone valerate
- Dexamethasone
- Prednisolone
- Ritonavir
- Triamcinolone
- Diflorasone
- Amcinonide
References
- ↑ Lacroix A, Feelders RA, Stratakis CA, Nieman LK (2015). "Cushing's syndrome". Lancet. 386 (9996): 913–27. doi:10.1016/S0140-6736(14)61375-1. PMID 26004339.
- ↑ Raff H, Carroll T (2015). "Cushing's syndrome: from physiological principles to diagnosis and clinical care". J. Physiol. (Lond.). 593 (3): 493–506. doi:10.1113/jphysiol.2014.282871. PMC 4324701. PMID 25480800.
- ↑ Else T, Kim AC, Sabolch A, Raymond VM, Kandathil A, Caoili EM, Jolly S, Miller BS, Giordano TJ, Hammer GD (2014). "Adrenocortical carcinoma". Endocr. Rev. 35 (2): 282–326. doi:10.1210/er.2013-1029. PMC 3963263. PMID 24423978.