Preferred Sample Type
Suitable Specimen Types
- EDTA Plasma
Specimen Transport
Transport samples to lab within 30 mins (1 hour if taken on ice). Samples recieved outside of this timeframe will be rejected.Sample Processing in Laboratory
Blood should be centrifuged as soon as possible. Plasma should be stored frozen
Turnaround Time
2 weeksSample Stability
-20 ºC
Plasma metanephrines
General Information
A phaeochromocytoma is a rare (0.1-1.0 % of hypertensive population), catecholamine-secreting tumor derived from chromaffin cells. When such tumors arise outside of the adrenal gland, they are termed extra-adrenal phaeochromocytomas, or paragangliomas. Because of excessive catecholamine secretion, phaeochromocytomas may precipitate life-threatening hypertension or cardiac arrhythmias. If the diagnosis of a phaeochromocytoma is overlooked, the consequences can be disastrous, even fatal; however, if a pheochromocytoma is found, it is potentially curable. Phaeochromocytomas are often associated with other endocrine tumours.
Symptoms of phaeochromocytoma are due to catecholamine excess and include:
- Sustained or paroxysomal hypertension
- Weight loss
- Sweating
- Headache
- Palpitations
- Anxiety
The metabolites of the catecholamines - normetadrenaline and metadrenaline (collectively known as metadrenalines or metanephrines) - can also be used for the diagnosis of phaeochromocytoma, with their meaurement in both urine and plasma recommended for diagnosis at the First International Symposium on Phaeochromocytoma in 2005 due to their increased diagnostic specificity when compared to catecholamines.
Measurement of urinary catecholamines & metanephrines is the first line test for diagnosis of phaeochromocytoma in uncomplicated patients
Patient Preparation
For measurements of plasma metanephrines, we suggest drawing blood with the patient in the supine position and use of reference intervals established in the same position, as per Endocrine guidelines
https://academic.oup.com/jcem/article/99/6/1915/2537399
If supine sampling is not possible, patient should be sitting down for 15 minutes prior to the test and preferably have fasted overnight (if overnight fast is not possible, a minimum 2 hour fast is recommended)
Reference Range
Supine Reference Ranges
Normetanephrine <730 pmol/L.
Metanephrine <450 pmol/L.
3-Methoxytyramine <180 pmol/L
Seated Reference Ranges
Normetanephrine <1180 pmol/L.
Metanephrine <510 pmol/L.
3-Methoxytyramine <180 pmol/L
Source of Reference Range
Peaston, R.T. et al, 2010. Performance of plasma free metanephrines measured by liquid chromatography–tandem mass spectrometry in the diagnosis of pheochromocytoma. Clinica chimica acta, 411(7-8), pp 546-552Specifications
- EQA Scheme?: Yes
- EQA Status: RCPAQAP