Also known as: Plasma Metanephrines
Formal name: Fractionated plasma free metanephrines (normetanephrine and metanephrine)
Related tests:Catecholamines, Plasma and Urine; Urine Metanephrines; Vanillylmandelic acid (VMA)
1. Can I have more than one pheochromocytoma at once?
Yes, especially when there is a strong family history of pheochromocytomas. A patient may have a tumor in each adrenal gland or occasionally in other locations.
2. Does the amount of plasma free metanephrines detected correspond to the size of the tumor?
No, it has more to do with the characteristics of the tumor. Even a very small tumor can produce large amounts of catecholamines.
3. Is it really necessary to follow the dietary restrictions and lie down before testing?
There is some disagreement over the specifics of how the sample should be collected. However, it is known that the level of catecholamines (and their metabolites) in the blood is affected by diet and stress levels. For test accuracy, interfering substances need to be avoided and the patient’s physical and emotional stress levels should be as low as possible.
This article was last reviewed on September 8, 2008.
This page was last modified on April 8, 2009.
The review date indicates when the article was last reviewed from beginning to end to ensure that it reflects the most current science. A review may not require any modifications to the article, so the two dates may not always agree.
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