Itsenko – Cushing syndrome is a syndrome that is caused by endogenous hyperproduction or prolonged exogenous administration of corticosteroids.
Classification
There are two types of classification.
The first type.
1. Itsenko-Cushing’s disease. 2. Itsenko — Cushing’s syndrome:
1) tumor:
a) adrenal gland; b) ectopic; c) gonad;
2) bilateral ACTG-independent non-modular hyperplasia
adrenal cortex;
3) administration with the purpose of treatment of glucocorticoids or ACTH drugs.
Second type
1. ACTH-dependent Cushing’s syndrome:
1) pituitary corticotropinoma;
2) ectopic ACTH syndrome, or syndrome of ectopic production of ACTH, as well as corticoliberin tumors; 3) exogenous AKTG.
2. ACTH Independent Cushing’s Syndrome:
1) exogenous glucocorticoid administration;
2) adenomarodrenal glands;
3) nodular and lateral hyperplasia of the cannons.
Etiology
In most cases, 90% of Cushing’s syndrome is pituitary adenoma. Another reason for the development of the syndrome is an ectopic ACTH-producing tumor.
Pathogenesis
When a corticotropin producing tumor is formed, the normal secretion of ACTH is disrupted. This is accompanied by an increase in the threshold of sensitivity of the pituitary to glucocorticoids. In some cases, the enhancement of cortisol production does not cause a decrease in ACTH production, i.e., the negative feedback mechanism is disturbed. An increase in steroid levels in the blood leads to a multiorgan and polysystemic lesion.
Clinic
In 90% of cases, obesity of the cushingoid type is observed. In this case, fat deposition is noted mainly on the abdomen, chest, neck and face. Quite often, obesity is accompanied by muscle atrophy of the upper and lower extremities. The deposition of adipose tissue in certain parts of the body is explained by its unequal sensitivity to glucocorticoids.
Muscle atrophy develops as a result of the catabolic effect of these hormones. The integuments acquire a marble shade, become thinned, dry, peeling and the appearance of a specific sheep smell. On the skin are streaky purple-red or purple. Striae are predominantly located on the abdomen, the inner surface of the thighs, in the area of the mammary glands and shoulders. The appearance of stretch marks is explained by the collapse of collagen in the skin and obesity. Hyperpigmentation of the skin may appear. A characteristic complication of Cushing’s syndrome is the development of osteoporosis. Its reason is the leaching of calcium from bone tissue under the influence of glucocorticoids. Changes in osteoporosis are most clearly seen in the thoracic and lumbar spine.
Due to the fact that osteoporosis is combined with atrophy of the back muscles, a change in the spine is manifested by the formation of scoliosis and kyphoscoliosis. With the development of the disease in childhood, the child lags behind in growth, as the development of the epiphyseal cartilages is inhibited.
With an excess of corticosteroids, alkalosis, arterial hypertension, myocardial dystrophy, heart rhythm disturbances, and heart failure often develop. Also, under the influence of a large number of corticosteroids in the blood, the following symptoms are observed: drowsiness, polyphagy, polydipsia, impaired thermoregulation, depression or aggressiveness.
With a long course of the disease, steroid diabetes mellitus develops, the functioning of the immune system is disturbed. Since there is an increase in the formation of sex hormones, women develop excessive male-type hair growth, as well as defeminization.
Laboratory and instrumental diagnostic methods
To confirm the diagnosis of Cushing’s syndrome, blood is tested for ACTH, as well as a large dexomethine zone test, determination of the daily excretion of free cortisol with urine. X-ray examination of the bones of the skull and spine are instrumental diagnostic methods.
With Itsenko-Cushing syndrome, radiographs show signs of osteoporosis. If there are signs of osteoporosis of the back of the Turkish saddle, this indicates a hypophenosis microadenoma. Also used is an adrenal ultrasound, computed tomography and magnetic resonance imaging.
Treatment
If the cause of the syndrome is pituitary adenoma, then treatment is selective transsphenoidal adenomectomy.
The use of steroidogenesis inhibitors, for example, lysodrene, mamomite, nosoral, is widely used from drug therapy. In the absence of a positive effect from all types of therapy, bilateral adrenalectomy is performed. If the cause of the syndrome is corticosteroids, then the affected adrenal gland is surgically removed, then temporary replacement therapy is performed until the function of the preserved adrenal gland is restored. If Cushing’s syndrome is associated with ectopic ACTH synthesis, then a hormone-producing tumor is surgically removed. Symptomatic therapy is also performed, which consists in the use of antihypertensive drugs, sugar lowering drugs, osteoporosis drugs, and potassium drugs.