How Do You Diagnose a Pheochromocytoma of the Adrenal Gland?The diagnosis of pheochromocytomas is made by showing the amount of adrenaline and its closely associated epinephrine-type hormones is higher than it should be in a patient's blood. Thus, the overproduction of these adrenaline-like hormones signifies that a tumor of the adrenal medulla is present, and thus the diagnosis of pheochromocytoma is made. (Pheochromocytoma is the name of adrenaline-producing adrenal tumors).
What are the Tests Used to Diagnose a Pheochromocytoma of the Adrenal Gland?Fist things first, the diagnosis of pheochromocytoma hinges on the treating physician entertaining the diagnosis in the first place. We can't diagnose a pheo if the doctor doesn't even think of it, and this is the number one reason that many pheochromocytomas do not get diagnosed. Making the diagnosis is usually straightforward by performing the following tests measuring adrenaline type hormones:
- Measurement of "plasma free metanephrines and normetanephrines" in the blood. This is a test that the doctor orders and they can do this on a single tube of blood. This is often an accurate test 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 and the diagnosis is made.
- Measurement of "urine fractionated metanephrines and catecholamines" in a 24-hour urine sample. Thus, the patient collects all of their urine for 24 hours (in a jug that the lab gives you), and then you take this jug of urine back to the lab. This is often an accurate test and has a high sensitivity and specificity and can be used for confirmatory testing for the diagnosis of pheochromocytomas.
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.
We have 12 pages of this website dedicated to pheochromocytomas (and paragangliomas since they are the same tumor--except they arise in the abdomen in certain places and NOT from within the adrenal gland.
Read more about symptoms of pheochromocytoma on our adrenal surgery blog