Pheochromocytoma Diagnosis

Biochemical Diagnosis

Initial testing for pheochromocytoma should include measurements of metanephrines (metabolic products of catecholamines) in blood, urine, or both. Elevation of more than 4-fold above the upper reference intervals is associated with close to 100% probability of pheochromocytoma or paraganglioma.

Tumor Localization Testing

Tumor localization testing should only be initiated if the biochemical test results indicate a relatively high probability of pheochromocytoma, except in patients with a hereditary predisposition or a previous history of the tumor. Computed tomography (CT) or magnetic resonance imaging (MRI) is the recommended method used for initial tumor localization. MRI is preferred in:

• Children or pregnant women due to concerns regarding radiation exposure
• Patients allergic to CT contrast dye
• Situations where no additional radiation exposure is desired
• Detection of extra-adrenal pheochromocytoma in a very unusual location