Metanephrines, Fractionated, Free, LC/MS/MS, Plasma Test
The Metanephrines, Fractionated, Free test measures normetanephrine and metanephrine in a plasma sample. Quest describes plasma metanephrine testing as used in the detection of pheochromocytoma, a hormone-producing tumor.
About this test
Metanephrine and normetanephrine are substances formed when the enzyme COMT breaks down the hormones norepinephrine and epinephrine outside of nerve cells. Quest describes plasma metanephrine testing as more sensitive, but potentially less specific, than measuring catecholamines directly for detecting pheochromocytoma.
The sample is analyzed using chromatography/mass spectrometry, a highly specific laboratory method. Quest notes that interpreting the result properly requires awareness of recent medication or substance use, such as antihypertensive drugs, alcohol or cocaine, and other factors like stress, severe congestive heart failure or myocardial infarction, since these can influence catecholamine and metanephrine release.
Test details
| Quest code | 19548 |
|---|---|
| Methodology | Chromatography/Mass Spectrometry |
| Sample type | 2.5 mL plasma |
| Patient preparation | Relax in a supine or upright position before your blood draw. Avoid alcohol, coffee, tea, tobacco and strenuous exercise before collection. Overnight fasting is preferred. |
| Collection | Quest patient service center |
Related tests and panels
Quest resources
Additional details
What this test looks at
The test reports three values: free metanephrine, free normetanephrine, and their total, all measured in plasma. Quest lists aliases including Metanephrines, Fractionated, LC-MS/MS, Plasma and Free Metanephrines for this same test.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does this test measure?
It measures free metanephrine and free normetanephrine, substances formed when norepinephrine and epinephrine are broken down, in a plasma sample analyzed by chromatography/mass spectrometry.
How is the sample collected?
The test uses a plasma sample from a blood draw.
Do I need to prepare for this test?
Relax in a supine or upright position before your blood draw. Avoid alcohol, coffee, tea, tobacco and strenuous exercise before collection. Overnight fasting is preferred. This is the preparation Quest publishes for this test; if your clinician gives you different instructions, follow theirs.
Why is this test used for pheochromocytoma?
Quest describes plasma metanephrine testing as used in the detection of pheochromocytoma, a hormone-producing tumor, and as more sensitive, though potentially less specific, than measuring catecholamines directly.
Can I get the Metanephrines, Fractionated, Free, LC/MS/MS, Plasma test without a doctor's visit or insurance?
Yes. The $475 cash price includes an independent physician's order, so no referral is needed, and insurance is never involved.