Cushing’s syndrome

Cushing's syndrome is the symptom set that occur when there is a increased levels of glucocorticoid hormones (cortisol). Glucocorticoids are made by the adrenal glands. This production of glucocorticoids is stimulated by another hormone called ACTH (adrenocorticotropic hormone) that is synthesized in the pituitary gland. In turn, ACTH is stimulated by another hormone that makes the hypothalamus.

The role of glucocorticoids is basically related to the protection of the body in stressful situations, so that its missions include those related to the regulation of blood sugar, causing an increase in blood sugar, the degradation of proteins and lipids. In addition, other functions are related to its anti-inflammatory, immunosuppressive properties and they tend to increase body water while retaining fluids.

The possible mechanisms by which corticosteroids are increased in the blood can range from those due to exogenous by means of drugs that are also the most frequent cause, or those that are caused by an increase in the levels of endogenous glucocorticoids or own of the organism that can be due to different causes.

What causes it?

The most frequent cause is the presence of a small tumor in the pituitary gland (pituitary microadenoma) that produces high amounts of ACTH that will overstimulate glucocorticoid synthesis in the adrenal glands. This mechanism is what is called Cushing's disease. Other times the alteration occurs in the hypothalamus which acts on the pituitary gland to release large amounts of ACTH.

Another possible cause Cushing syndrome is due to synthesis of ACTH by other cells that are not in the pituitary. The most frequent causes of this situation are carcinoid tumors, lung cancer, pheochromocytomas, tumors of the thymus, pancreas, ovary and medullary thyroid carcinoma.

Finally, another cause of endogenous Cushing syndrome is the presence of some type of tumor in the adrenal glands that produces glucocorticoids indiscriminately.

Symptoms

• There is usually a obesity with a characteristic distribution, due to the fact that the fat accumulates in the abdominal and posterior region of the neck giving a hump-like appearance, with a face in the shape of a full moon, and very thin extremities with significant muscular atrophy in more advanced cases.
• There is usually frequent hair loss although there are also traits of virilization, more striking in women where hair appears in locations more typical of men, and menstrual disorders in women.
• It usually produces alterations or skin lesions such as Vinous red streaks (mainly in the abdomen), acne Y capillary fragility with frequent bruising.
• It is also seen osteoporosis accelerated by the effect of corticosteroids on bone loss and poor wound healing.
• Due to the effect of glucocorticoids on carbohydrate metabolism, there is usually a increased blood sugar manifested in the form of glucose intolerance.
• In addition, due to the weak mineralocorticoid effect of glucocorticoids, the tendency to fluid retention and salt producing arterial hypertension.

Diagnosis

The diagnostic method goes through the cortisol measurement in urine for 24 hours and demonstrate the impossibility of suppressing its secretion by administering dexamethasone. From here, tests can be done to find out the origin of the syndrome. For example, it will be important to measure the levels of ACTH because in the case of Cushing due to excess ACTH it will be high and in the case of direct involvement of the adrenal glands the ACTH will be low.

Imaging techniques, especially magnetic resonance, allow you to see the pituitary tumors that cause the syndrome. The CT of the abdomen and chest It can be useful to assess the adrenal glands and assess the existence of a tumor at that level, or other tumors present in other locations in the body that can produce ACTH. The scintigraphy with octreotide it helps to locate ACTH-producing tumors throughout the body.

Treatment

Treatment will go aimed at treating the cause.

• In the case of adrenal involvement by some tumor in general the treatment usually goes through the surgery.
• In the case of a adenoma removal usually heals the condition.
• If it is a adrenal carcinoma This tends to metastasize frequently. It is usually done surgical removal and chemotherapy treatment with mitotane.
• Yes there are pituitary tumor it also usually requires surgical treatment and removal total or partial pituitary gland, sometimes followed by radiotherapy if healing is not achieved after surgery.
• In the case of a ACTH-generating tumor in a different location to the pituitary is due surgically remove if it is possible. But if this cannot be done, it must eliminate the function of the adrenal glands either by surgical removal or by treatment based on drugs that cancel the functionality of the adrenal glands. In the case of canceling both adrenal glands, replacement therapy with glucocorticoids and mineralocorticoids should be provided.

Precautionary measures

In general, the most important preventive measure is to avoid exogenous corticosteroids, unless they are adequately provided. If this is not the case, there are no preventive measures for Cushing's syndrome.