Do you measure plasma metanephrines in an asymptomatic, normotensive patient with an adrenal incidentaloma below 10 Hounsfield units on non-contrast CT, given that a small proportion of pheochromocytomas can appear lipid-rich on imaging?

The probability of a positive result would be very low unless the patient is hypertensive or has suggestive symptoms.

Do you have a citation for the claim that "a small proportion of pheochromocytomas can appear lipid-rich on imaging"? Because the evidence I've seen is that <10 HU has literally 100% sensitivity for ruling out Pheochromocytomas, as cited in the most recent European guidelines.