Pheochromocytoma

pheochromocytoma [‚fē·ō‚krō·mō·sī ′tō·mə]

(medicine)

A tumor of the sympathetic nervous system composed principally of chromaffin cells; found most often in the adrenal medulla.

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Pheochromocytoma 

(also medullary chromaffinoma), a tumor of the cortical layer of the adrenal glands or sympathetic paraganglia that is characterized by the increased secretion of epinephrine and norepinephrine. The condition usually develops in youth or early middle age. The chief symptom is secondary hypertension, which may be persistent (often reaching a critical point with increased arterial pressure) or intermittent. The disorder is rarely found in its latent form, or without hypertension.

During severe attacks, pheochromocytoma is marked by a sudden and sharp increase in arterial pressure, draining of blood from the skin and mucous membranes, coldness of the extremities, chills, palpitation, headache, dizziness, shortness of breath, and tachycardia or, less frequently, bradycardia. The blood usually shows increased levels of sugar and leucocytosis. Casts, or cylinders, and protein are observed in the urine. The attack may last from several minutes to several hours; copious urination often accompanies its ending. Hypertensive crises may result from emotional disturbances, physical stress, chilling of the body, overheating, deep abdominal palpation, or pressure exerted on the tumor by body movements. The attacks grow more frequent and severe with the advance of the disease. Death may occur as a result of brain hemorrhage or severe cardiac insufficiency (pulmonary edema). Pheochromocytoma during pregnancy endangers both the mother and the fetus; early removal of the tumor is therefore indicated—or, alternatively, termination of the pregnancy.

The diagnosis of pheochromocytoma is based on its characteristic symptoms during an attack, the results of urine analysis (that is, sharply increased secretion of catecholamines), and X-ray examinations (specifically, roentgen diagnosis through the injection of oxygen into the cellular tissue surrounding the adrenal glands). The condition is also identified through its rapid improvement following the intravenous injection of adrenolytic agents, such as troparphene and phentolamine. Surgery is the method of treating the disease.

REFERENCE

Feokhromotsitoma. Moscow, 1965.

N. R. PALEEV