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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.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



(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.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Pheochromocytoma is a rare catecholamine secreting tumour which is of chromaffin cells of adrenal medulla (90%) or extra-adrenal sympathetic para-ganglia.
Surgical resection is the treatment of choice and in the setting of bilateral pheochromocytoma, cortical-sparing procedures should be considered (4).
Pheochromocytoma may become malignant through their metastatic tendency, and the metastases can help us diagnose a malignant pheochromocytoma.
In children presenting with unexplained cardiovascular findings (hypertension, tachycardia, etc.), rash and neurological symptoms, mercury intoxication mimicking pheochromocytoma should be considered in the differential diagnosis.
The Azedra (iobenguane I 131) injection for intravenous use has been approved by the US FDA for the treatment of adults and adolescents age 12 and older with rare tumours of the adrenal gland (pheochromocytoma or paraganglioma) that cannot be surgically removed (unresectable), have spread beyond the original tumour site and require systemic anticancer therapy.
Clinical and Pathological Features of Pheochromocytoma in the Horse: A Multi-Center Retrospective Study of 37 Cases (2007-2014).
Composite pheochromocytoma with a malignant peripheral nerve sheath tumor: Case report and review of the literature.
Pheochromocytoma and paraganglioma: an Endocrine Society Clinical Practice Guideline.
Primary vesical pheochromocytoma. Urology 1983;21:20-5.
Dahia, "Pheochromocytoma and paraganglioma pathogenesis: learning from genetic heterogeneity," Nature Reviews Cancer, vol.
Plasma and 24-hour urine metanephrines were elevated at 11.8 nmol/L (normal value: 0-0.89 nmol/L) and 2223 [micro]g/24h (normal value: 0-400 [micro]g/24h), respectively, supporting the diagnosis of pheochromocytoma. Once heart failure condition was stabilized, carvedilol was switched to prazosin and metoprolol.