Cushing's syndrome causes

Cushing's syndrome Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Cushing's syndrome from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
Chest X Ray
CT
MRI
Echocardiography or Ultrasound
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies
Case #1
Cushing's syndrome causes On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Cushing's syndrome causes All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Cushing's syndrome causes
CDC on Cushing's syndrome causes
Cushing's syndrome causes in the news
Blogs on Cushing's syndrome causes
Directions to Hospitals Treating Cushing's syndrome
Risk calculators and risk factors for Cushing's syndrome causes

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Cushing’s syndrome occurs when the body’s tissues are exposed to high levels of cortisol for too long. 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. Normally, the production of cortisol follows a precise chain of events. First, the hypothalamus, a part of the brain about the size of a small sugar cube, 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

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, affects women five times more often than men.

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, and men are affected three times more often than women.

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—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

• Prednisolone