Pheochromocytoma

A pheochromocytoma is a hormonally active tumor arising from the chromaffin medulla of the adrenal glands, paganglia or sympathetic nodes. The disease is relatively rare and averages 1-3 cases per 10 000 patients. Among individuals with elevated arterial pressure, pheochromocytoma occurs 2–3 times more often. A pheochromo cytoma usually occurs between the ages of 20-50 years and equally often affects both men and women.
Historical data. The disease was first described in 1886 by Frenkiel. The term “pheochromocytoma” suggested in 1912 the Peak by the name of the predominant cells colored by salts of the chromic acid in brown. Etiology. The cause of the disease is unknown. Genetic predisposition to the development of pheochromocytoma, especially in children, was noted.

Pathogenesis. The pathogenesis of pheochromocytoma is due to the overproduction of chromaffin cells of a catecholamine tumor.
(adrenaline, norepinephrine, dopamine).
Depending on the ratio and the amount of adrenaline or
norepinephrine symptoms of the disease may vary.

If adrenaline is predominant, a collapse can develop, which is caused by the expansion of skeletal muscle vessels and a decrease in the peripheral resistance of the vessels; excitement, tremor, pupil dilation, tachycardia, hyperglycemia, glucosuria occur, bradycardia, an increase in both systolic and dystolic blood pressure, basal metabolism, etc. A certain role in the pathogenesis of the disease is given by the increased excitability of the vegetative centers of the hypothalamus amus and cerebral cortex.

In the pathogenesis of hypertension in pheochromocytoma, the main role belongs to an excess of catecholamines. The renin-angiotensin-aldosterone system also has a certain value in the genesis of hypertension. It is believed that an increase in the activity of renin in pheochromocytoma is due, on the one hand, to direct stimulation of renin secretion by catecholamines, and on the other, to a violation of the intrarenal blood circulation.

An increase in aldosterone production in a pheochromocytoma is associated with the stimulating effect of the renin-angiotensin system and a decrease in circulating blood volume under the influence of catecholamines. Owing to an excess of catecholamines, the early development of atherosclerosis of the arteries occurs. There are relative coronary insufficiency and myocardial hypoxia
with the accumulation of lactic acid in it and a decrease in the content of glycogen. The concentration of sodium inside the cell increases, while that of potassium decreases. As a result of these disorders of the ~ cardiac muscle, necrosis can occur even with unchanged coronary vessels.

Due to an excess of catecholamines, a violation of carbohydrate metabolism can occur, up to the development of diabetes.
Pathological anatomy. The most frequent localization of a pherochromocytoma is the medulla of one of the adrenal glands. . Significantly ‘less “TlTlU-15u0 cases) tumor has vnenadgsh- chechnikovuyu (ekstraadrenalovuyu) [localization When vnenadpochech- shTkovoy lokaTshZatsyi foohromotsitoma most raspolaga- etsya in sympathetic paraganglia along the abdominal aorta and the place of its bifurcation, at least -. In the mediastinum, sometimes in the cranial cavity of the bladder wall. In approximately 10% of cases, the pheochromocytoma is bilateral or multiple. Most often, the pheochromocytoma located in one adrenal gland has a benign structure, and with bilateral or extracorporeal Chronic localization – malignant.