Both plasma metanephrines and plasma catecholamines have been used for the diagnosis of pheochromocytoma. If plasma metanephrines and/or catecholamines are not available, then the next best test is urinary fractionated metanephrines and/or catecholamines.
The 24-hour urine tests for metanephrines and catecholamines remain useful screening tests for pheochromocytoma, based on data from some research groups showing good diagnostic specificity of urine testing.1 The urine specimen requires a complete 24-hour collection and an acid preservative must be added to the collection container.
Urinary VMA is no longer used as a diagnostic test for pheochromocytoma. However, urinary VMA can be used in conjunction with urinary HVA for the diagosis of neuroblastoma.