Evaluation of screening tests for pheochromocytoma

Autonomous and excessive synthesis of catecholamines is the predominant feature of pheochromocytoma tissue. An increased amount of catecholamines in the sympathetic neuron is the precondition for positive pharmacological tests. High rates of false-negative results are seen because of a down-regulation of adrenoceptors in pheochromocytoma patients. The separate measurement of the catecholamines adrenaline and noradrenaline and their metabolites metanephrine and normetanephrine in urine or serum are the most sensitive screening tests.