Cortisol Elevation in Pheochromocytoma

Clinical Significance

Some patients with pheochromocytoma may experience symptoms secondary to increased adrenocortical steroid levels, including hypertension, hyperglycemia, hypokalemia, and muscle atrophy, as noted by the National Comprehensive Cancer Network 1

When evaluating patients with resistant hypertension, screening for pheochromocytoma involves measuring circulating catecholamine metabolites, as recommended by the American Heart Association 2, 3
The screening test of choice is measurement of plasma free metanephrines (sensitivity 96%-100%, specificity 89%-98%) or urinary fractionated metanephrines (sensitivity 86%-97%, specificity 86%-95%), according to the American Heart Association 2, 3
If cortisol levels are also elevated, a 24-hour urine cortisol test is recommended to evaluate for Cushing syndrome, as suggested by the National Comprehensive Cancer Network 1

Physicians should be aware that some pheochromocytomas can present with features mimicking metabolic syndrome due to cortisol excess, as noted in Hypertension 2
After surgical removal of pheochromocytoma, patients may require corticosteroid supplementation until recovery of the hypothalamus-pituitary-adrenal axis, as recommended by the National Comprehensive Cancer Network 1

Hypertensive patients frequently have elevated levels of catecholamine metabolites, especially with obesity and obstructive sleep apnea, usually <4 times the upper limit of normal, as reported in Hypertension 2
The average 3-year delay in diagnosis of pheochromocytoma highlights the importance of considering this diagnosis in resistant hypertension, as emphasized in Hypertension 2