Definition | Cushing's disease – Cushing's syndrome

Cushing's disease is one of the forms of syndrome from Cushing. It is due to a adenoma of the'pituitary gland which induces excessive production ofhormones corticosteroids by adrenal glands. It's a very rare disease which affects about one to three in a million people a year. In children, Cushing's disease affects boys more, but in adults (around 40), it affects women more.

Causes of Cushing's disease

The secretion of cortisol is normally controlled by another hormone, theACTH ((Adreno Cortico-Tropic Hormone or corticotropic hormone), produced by the pituitary gland, a Endocrine gland located at the base of brain. When an adenoma (tumor benign) develops in the pituitary gland, the secretory cells multiply which leads to an overproduction of ACTH, which in turn stimulates the production of cortisol by the adrenal glands. Cushing's disease has no identified cause, nor genetic neither environmental.

Note that there are other causes endogenous Cushing's syndrome, but which are not strictly speaking Cushing's disease:

• tumor in organs outside the pituitary gland that secrete ACTH;
• tumor of the adrenal gland that secretes an excess of cortisol.

Cushing's syndrome can also have causes exogenous, by prolonged administration of large doses of corticosteroids of synthesis.

Symptoms of Cushing's disease

The most characteristic signs of Cushing's disease are weight gain and a change in appearance physical, due to prolonged exposure to corticosteroid hormones. Patients have excess fat on the upper body, sometimes with a lump in the upper part back (buffalo hump), a puffy, rounded face, thinned arms and legs. The other evocative signs:

• muscle wasting resulting in lack of tone;
• thinning of the skin, with appearance of hematomas and difficulty in healing;
• purplish streaks like stretch marks on theabdomen and the thorax.

The long-term consequences:

• high blood pressure;
• osteoporosis with risk of fatigue fracture;
• decrease in resistance infections;
• phlebitis;
• increased risk of diabetes ;
• increased risk of kidney stones ;
• mental disorders (depression, irritability, sleeping troubles see hallucinations).

Children with Cushing's syndrome are stunted and stay short. In some people, the adrenal glands also produce a large amount of male sex hormones, which results in excessive hair on the face and body, as well as baldness in women.

Treatment of Cushing's disease

Cushing's disease can be cured byablation of the pituitary adenoma responsible for hypersecretion of ACTH. It is a delicate but not very traumatic operation, which consists in introducing a endoscope in the nostril to the pituitary gland. When the adenoma is well identified, the surgery pituitary allows a remission total in 70 to 80% of cases. The patient then resumes normal appearance within a few months. The result is worse when the adenoma is too small to spot or if it is too large. In case of recidivism, reoperation or radiotherapy can be considered.

After the operation, medical monitoring is necessary because removal of the pituitary gland sometimes results in abnormally low levels of cortisol, thyroid and sex hormones, andADH (antidiuretic hormone). The latter induces a diabetes insipidus, characterized by permanent thirst and abundant urine.