Generality
Cushing's syndrome is a complex of signs and symptoms generated by chronic exposure to high levels of glucocorticoids, hormones produced by our body and used in the treatment of inflammatory diseases. Cushing's syndrome can therefore be sustained by endogenous factors (excessive synthesis of glucocorticoids ) or, more commonly, from exogenous factors (treatment with corticosteroids, such as prednisone, prednislone, betamethasone, etc.).
To investigate the physiological action of these adrenal hormones and the drugs that mimic their action, consult the articles on the site dedicated to corticosteroids and cortisone drugs.
Causes
As anticipated, the endogenous forms of Cushing are rare (2.5-6 cases per million inhabitants), have a slow onset and are often difficult to diagnose. More common in women (F: M 8: 1), from a pathogenetic point of view they are classically divided into two variants: ACTH dependent (80%) and ACTH independent (20%).
ACTH, or adrenocorticotropic hormone, is produced by the pituitary gland as a stimulus for the adrenal synthesis of corticosteroid hormones (glucocorticoids and mineralocorticoids); a benign tumor of this gland (pituitary adenoma) is present in approximately 80% of cases of endogenous ACTH dependent Cushing, while in the remaining 20% of cases non-pituitary (usually pulmonary) tumors that produce ACTH cause a Cushing's syndrome, so-called "ectopic".
60% of the endogenous independent ACTH forms are supported by an adrenal adenoma, while in the remaining cases the syndrome is triggered by the presence of an adrenal carcinoma.
In most cases Cushing's syndrome is caused by excessive and prolonged administration of cortisone-based drugs (independent ACTH Cushing iatrogenous), while iatrogenic forms of ACTH therapy (ACTH dependent cushing iatrogenic) are rare.
Symptoms
To learn more: Symptoms Cushing syndrome
The signs and symptoms (see figure) are of variable entity and variously associated among them. Sometimes the disease presents with the characteristics of the metabolic syndrome or with a partial or nuanced clinical picture. If you feel you have Cushing Syndrome symptoms contact your doctor to determine the cause in collaboration with an endocrinologist, but do not suspend cortisone therapy of your own accord for any reason.
Diagnosis and treatment
To learn more: Drugs for the treatment of Cushing's syndrome
Although the diagnosis of a full-blown picture is fairly easy, very often, especially in endogenous forms, it can be difficult. In the presence of a suspicion arising from the patient's physical examination, the diagnosis of Cushing's syndrome is confirmed by the presence of high levels of cortisol, which can be dosed in the blood, in urine collected in 24 hours or in saliva. In the latter case, the sample is collected around midnight, time of day when cortisol levels in healthy people are quite low. Clinical tests are also performed after the administration of suppressors, such as dexamethasone, or hormonal stimulators (such as ACTH); it is also possible to evaluate the plasma levels of adrenocorticotropic hormone to highlight the forms caused by ACTH hypersecretion.
In addition to clinical examinations, instrumental investigations are often required, such as a CT scan or an MRI scan to assess the appearance of the adrenal glands and the pituitary gland.
The treatment of Cushing's syndrome is subject to a correct identification of its origins. In iatrogenic forms, the most frequent, the doctor generally opts for a gradual reduction of the doses or for the interruption of the treatment in favor of alternative therapies. The primitive forms of tumor origin can be resolved by surgical interventions or radiant therapies. In some patients suffering from Cushing's syndrome, for example waiting or in preparation for surgery or when this is not viable, it is necessary to use drugs that reduce the production of cortisol, such as Ketoconazole and Mitotano.
