What Blood and Urine Tests are Required for Pheochromocytoma of the Adrenal Gland?

Lab testing of Pheochromocytoma: What Tests are Used to diagnose Pheochromocytomas and Paragangliomas?

Laboratory testing of the blood and urine of a patient provides the primary means to determine if a pheochromocytoma is present. But first, the diagnosis of pheochromocytoma hinges on the treating physician entertaining the diagnosis in the first place. Making the diagnosis is usually straightforward by performing the following tests measuring adrenaline type hormones on blood and urine samples:

• Measurement of plasma free metanephrines and normetanephrines. This blood test is typically quite accurate with sensitivity of 97-100% and a specificity of 85-89%. Plasma free metanephrines levels above 3-4 times normal almost always indicates the presence of pheochromocytoma.
• 24-hour collection of urine fractionated metanephrines and catecholamines. This urine test is typicaly quite accurate and has a high sensitivity and specificity and can be used for confirmatory testing or in lieu of plasma testing.

Drugs and Medications that Can Affect Laboratory Testing for Pheos. It is important to know that many medications may affect (increase) adrenaline type hormones so it is important that you tell us and your doctor what medications (if any) you were on while being tested.

This list some of the medication that may interfere with measuring adrenaline type hormones: • Tricyclic antidepressants (including cyclobenzaprine)
• Levodopa
• Buspirone and antipsychotic agents
• Serotonin and noradrenaline reuptake inhibitors
• Monoamine oxidase inhibitors
• Drugs containing adrenergic receptor agonists (e.g., decongestants)
• Amphetamines
• Prochlorperazine
• Reserpine
• Withdrawal from clonidine and other drugs (e.g., illicit drugs, ethanol)
• Illicit drugs (e.g., cocaine, heroin)

Once, it has been established that the adrenaline type hormones are elevated and you have a pheochromocytoma or paraganglioma, then you would have a scan (X-ray). Scans for pheochromocytoma or paraganglioma is discussed here.

IMPORTANT: If you have a pheochromocytoma or paraganglioma you need (in, preparation for curative surgery) to be treated with medications until your pheochromocytomas or paraganglioma is removed. The goal is to obtain stabilization in the blood pressure for 1-2 weeks prior to surgery.