Pheochromocytoma laboratory findings
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Laboratory Findings
The diagnosis can be established by measuring catecholamines and metanephrines in plasma or through a 24-hour urine collection. Care should be taken to rule out other causes of adrenergic (adrenalin-like) excess like hypoglycemia, stress, exercise, and drugs affecting the catecholamines like stimulants, methyldopa, dopamine agonists, or ganglion blockingantihypertensives. Various foodstuffs (e.g. vanilla ice cream) can also affect the levels of urinary metanephrine and VMA (vanillyl mandelic acid).
Another test is for the clinician to press gently on the adrenal gland. A pheochromocytoma will often release a burst of catecholamines, with the associated signs and symptoms quickly following. This method is not recommended because of possible complications arising from a potentially massive release of catecholamines.
Pheochromocytomas occur most often during young-adult to mid-adult life. Less than 10% of pheochromocytomas are malignant (cancerous), bilateral or pediatric.
These tumors can form a pattern with other endocrine gland cancers which is labeled multiple endocrine neoplasia (MEN). Pheochromocytoma may occur in patients with MEN 2 and MEN 3. VHL (Von Hippel Lindau) patients may also develop these tumors.
Patients experiencing symptoms associated with pheochromocytoma should be aware that it is rare. However, it often goes undiagnosed until autopsy; therefore patients might wisely choose to take steps to provide a physician with important clues, such as recording whether blood pressure changes significantly during episodes of apparent anxiety.