Biochemical screening for pheochromocytoma
Plasma metanephrines have the highest sensitivity (∼96%), but a low specificity (∼85%), so this test is most appropriate for patients at very high risk (e.g., those with family histories or strong histories and a positive scan).
A 24-hour urine collection for fractionated metanephrines can be recommended for patients at low risk; vanillylmandelic acid (false-positive rate in patients at low risk ∼15%) and total catecholamines can be added for those at higher risk. Collecting a 24-hour urine after a “spell” can increase the sensitivity of urinary tests.
