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[‚fē·ō‚krō·mō·sī ′tō·mə]
A tumor of the sympathetic nervous system composed principally of chromaffin cells; found most often in the adrenal medulla.



(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.


Feokhromotsitoma. Moscow, 1965.


References in periodicals archive ?
Genetic consultation and testing were ordered due to the known association of pheochromocytoma with several genetic variations (see discussion below).
Unlike the pheochromocytoma, data on surgery for paraganglioma with a robotic approach are limited and related only to few case reports.
Malignant pheochromocytomas and paragangliomas: A diagnostic challenge.
Pheochromocytoma and paraganglioma: Current functional and future molecular imaging.
Sympathetic paragangliomas have a greater propensity for secretion and are divided into pheochromocytomas of the adrenal medulla and extra-adrenal paragangliomas.
On CT, pheochromocytomas can be seen as homogeneous or heterogeneous solid or cystic masses, possibly showing some calcification.
Differential diagnosis and laparoscopic treatment of adrenal pheochromocytoma and ganglioneuroma.
Pheochromocytoma : state-of-the-art and future prospects.
2+] homeostasis in microsomes (Kodavanti and Ward 2005) and pheochromocytoma (PC12) cells (Dingemans et al.
A kind of recurrent, short-lasting headache has been reported to be associated with transient, paroxysmal elevations of blood pressure in patients without underlying causes of pheochromocytoma.
Unlike chronic hypertension, acute hypertension can cause headaches in specific circumstances, the most common being pheochromocytoma, which presents with headache in up to 80% of cases as part of a complex of symptoms.