Cushing's disease and Cushing's syndrome

December 2016


Definition


Cushing's disease is a condition in which all symptoms are grouped under the term Cushing's syndrome. We can distinguish these two entities, because even if Cushing's disease is in nearly three quarters of cases the sole pathology causing the symptoms described below, there are some other causes that are responsible for the same syndrome. Cushing's disease is manifested as a tumor located in the pituitary gland, a gland that secretes an excess of a hormone called ACTH (adrenocorticotropic hormone), which acts directly on the adrenal gland. This tumor will cause excessive functioning of the adrenal cortex, the body responsible for the secretion of glucocorticoids. In addition, other diseases may be responsible for the same clinical symptoms and therefore fulfill the same criteria as Cushing's syndrome such as paraneoplastic syndrome, due to ACTH secretion from another tumor or certain lung tumors with the possibility of adrenal adenoma or adrenocortical carcinoma, both of which are adrenal tumors. In all cases, the common denominator is excess secretion of glucocorticoids by the adrenal gland.

Symptoms


In Cushing's disease just like Cushing's syndrome, there are the following symptoms:
  • swelling of the face, which becomes very round and is described as "lunar";
  • abdominal obesity;
  • localized redness, mainly on the limbs and abdomen;
  • the skin becomes thinner and more fragile;
  • purpuric spots are frequent;
  • loss of muscle mass;
  • bone fragility, osteoporosis;
  • high blood pressure;
  • sexual disorders;
  • behavioral problems;
  • occasionally, depression.

Note that in Cushing's disease and paraneoplastic syndrome, it is possible for the skin to become darker.

Diagnosis


The diagnosis is made by a clinical exam coupled with additional tests:
  • measuring of ACTH, which can guide the diagnosis: it is increased in the case of Cushing's disease or paraneoplastic syndrome, and is decreased in adrenal tumors;
  • measuring of cortisol in several times per day;
  • measuring of cortisol in urine, increased in comparison to normal;
  • so-called "dynamic tests" are also frequently performed after the injection of a product called dexamethasone;
  • in the case of diminished ACTH, adrenal imaging will be performed, including a CT scan or MRI;
  • in the case of increased ACTH, as in Cushing's disease, a pituitary MRI allows for the studying of the pituitary gland.

Treatment


The treatment of Cushing's syndrome depends on the cause of the hypersecretion of glucocorticoids. Usually, the tumor involved in the excess secretion of glucocorticoids must be surgically removed.

Related

Original article published by . Translated by Jeff. Latest update on July 1, 2013 at 01:11 PM by Jeff.
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