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Pheochromocytoma

The pheochromocytoma is a chromaffin tumor which produces, accumulates and allocates catecholamines — adrenaline and noradrenaline. To a bowl of all the pheochromocytoma proceeds from a medulla of adrenal glands, but the chromaffin cells located in the field of sympathetic gangliyev in various body parts can be its source (primary pheochromocytomas located out of adrenal glands designate as paragangliomas). Release of catecholamines from a tumor leads to vegetative katekholaminovy paroxysms and arterial hypertension, is frequent in the form of heavy hypertensive crises. Sometimes the pheochromocytoma gains lines of malignant growth and can give metastasises that is more characteristic of extraadrenal localization of this tumor. Most often the pheochromocytoma is found in persons of young or middle age, but can occur also at children. Approximately in 10% of cases the pheochromocytoma is shown at several family members and autosomal is inherited it is prepotent.

At the characteristic of pheochromocytomas the approximate "rule of 10" is sometimes provided. About 10% of patients with a pheochromocytoma have no arterial hypertension; in 10% of cases the pheochromocytoma is located out of adrenal glands, but within an abdominal cavity (at the same time the tumor develops in areas sympathetic gangliyev, the located on the course celiac and mezeiterialny arteries); 10% of vnepadpochechnikovy pheochromocytomas are localized also out of an abdominal cavity (in a bladder, in a thorax, in the field of cervical sympathetic gangliyev on the course IX and X couples of cranial nerves). Among patients — about 10% of children; in 10-15% of cases the pheochromocytoma is found in several family members. In 10% of cases the pheochromocytoma is found in both adrenal glands, and such bilateral arrangement is more often observed at hereditary forms of a disease. Approximately 10% of patients at the time of detection of a tumor already have metastasises.

Clinical manifestations of a pheochromocytoma

The leading symptom of an illness is increase of arterial pressure. Crises with sudden increase of arterial pressure to 280-300/180-200 mm of mercury are most characteristic. There is a headache, sensation of fear, profuse sweat, tachycardia, sharp blanching or erubescence. Quite often there are anginous pains, abdominal pains, nausea, vomiting. Various disturbances of a heart rhythm, among them such heavy as ventricular tachycardia and even fibrillation of ventricles of heart are noted.

In the period of crisis find a hyperglycemia, a neutrophylic leukocytosis, fervescence.

Sometimes the pheochromocytoma is shown constant arterial hypertension with emergence on its background of crises which can be not so sharply expressed, as at the first option of a current.

Katekholaminovo-gipertenzivny crisis can end letalno at the picture of shock reminding acute adrenal insufficiency. Persistent arterial hypertension quite often leads to death from a brain stroke or a myocardial infarction.

Diagnosis of a feokhromonitoma

For recognition of a feokhromonitoma the following matters:
• an assessment of the clinical data allowing to suspect a pheochromocytoma;
• definition of catecholamines or their metabolites in daily amount of urine (when there are clear symptoms of a disease);
• results of a computer tomography of adrenal glands. For identification of extraadrenal localization of a feokhromonitoma use a computer tomography, an aortografiya. In cases when the tumor by means of the listed methods does not manage to be found, apply introduction 131I a metayodobenzilguanidin (131I MIBG) who is taken a tumor that allows to visualize it scintigraphically.

Acute management to the patient with hypertensive crisis at a pheochromocytoma

Fast intravenous administration of 5 mg and - phentolamine adrenoblocker (5 mg of dry phentolamine in an ampoule part in 1 ml of water). Injections repeat each 5 min. before lowering of arterial pressure. After stabilization of arterial pressure at the moderate level each 2 — 4 h in a dose of 2,5-5 mg repeat injections.

Instead of phentolamine it is possible to apply and - adrenoblocker Tropaphenum.

The tachycardia inherent to a pheochromocytoma, during lowering of arterial pressure under influence and - adrenoblockers can even amplify in this connection at this stage the patient can appoint β-adrenoblocker ((((((((((propranolol), eliminating in this case tachycardia.

It is impossible to begin stopping of hypertensive crisis at a pheochromocytoma with β-adrenoblockers, as blocking a promoting effect of adrenaline on heart, they eliminate also its vasodilating action that leads to a bigger growth of arterial pressure.
Treatment — operational. During preoperative preparation to the patient appoint it is long acting and - adrenoblocker phenoxybenzamine.

At impossibility of operation (a serious general condition of the patient or existence of metastasises) for the purpose of suppression of synthesis of catecholamines and lowering of arterial pressure appoint metirozin — inhibitor tirozingidroksilazy*. The metastasizing pheochromocytomas treat by means of the combined chemotherapy (for example, Cyclophosphanum, Vincristinum and dacarbazine) or by introduction of high doses 131I MIBG.

Metirozin — enzyme which turns tyrosine and tofu. Insufficiency of a dofa results in insufficiency of dopamine, and also noradrenaline and adrenaline which are synthesized from this predecessor. After reception of a metirozin — (and-metiltprozina) through a mouth within 3 days synthesis of catecholamines decreases to 80%.

 
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