Test Overview
Test Methodology

Liquid Chromatography - Tandem Mass Spectrometry (LC-MS/MS)

Test Usage

Screening test for presumptive diagnosis of catecholamine-secreting pheochromocytomas or paragangliomas.

Reference Range *

Metanephrine, Plasma <0.5 nmol/L
Normetanephrine, Plasma <0.9 nmol/L

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

While most circulating metanephrines are derived directly from adrenal secretion, peripheral conversion of catecholamines makes a small contribution. Therefore, substances that increase endogenous catecholamine levels can result in borderline elevations of plasma metanephrines. These include monamine oxidase inhibitors (MOIs), catecholamine reuptake inhibitors, and some anesthetic gases, particularly halothane. Artifactually decreased plasma metanephrine levels may be observed when patients are already receiving metyrosine treatment.

Test Details
Days Set Up
Wednesday, Friday
Analytic Time

8 hours

Soft Order Code
MiChart Code
Metanephrines, Plasma Fractions
  • Normetanephrines, Plasma
  • Fractionated Metanephrines, Plasma
  • PMET
  • Metanephrines, Fract., Free, P
Chemical Pathology
Drug Analysis
Specimen Requirements

Collect specimen in a lavender top tube. Centrifuge, aliquot plasma into a plastic vial and freeze. Discontinue epinephrine and epinephrine-like drugs at least 1 week before obtaining the specimen. The patient must fast and abstain from smoking tobacco for at least 4 hours before the specimen is drawn. The patient may drink only water during the fasting period.

Special Handling

Fasting specimen.

Normal Volume
1 mL EDTA plasma
Minimum Volume
0.5 mL EDTA plasma
Additional Information

Tested using a laboratory developed assay performed on a Waters liquid chromatography tandem mass spectrometry (LC-MS/MS) system. Results determined from different manufacturers and/or methods may not be comparable.

CPT Code
Fee Code