Table 7: Pheochromocytoma: Screening and diagnosis *
Biochemical screening tests for pheochromocytomas:
- To screen for pheochromocytomas, 24 h urinary total metanephrines (sensitivity 95%) and urinary metanephrine-to-creatinine ratio (sensitivity 100%) should be assessed. Plasma catecholamines and, where available, plasma metanephrines may also be considered if clinical suspicion is high, particularly during a hypertensive episode or for those with familial forms. Urinary or plasma VMA measurements should not be used as screening tests. In a low risk setting, plasma fractionated free metanephrine measurements can be used to rule out pheochromocytoma.
- In the presence of borderline biochemical test results (e.g., plasma noradrenaline and adrenaline levels of approximately 500ng/L to 2000 ng/L) or potentially false positive results, repeated testing and/or the clonidine suppression test may be used.
* Reprinted with permission of CHEP