Which laboratory test is commonly elevated in pheochromocytoma?

Which laboratory test is commonly elevated in pheochromocytoma?

• A. 24-hour urinary metanephrines and catecholamines
• B. Serum prolactin
• C. Serum sodium
• D. Serum calcium

Answer: (A)

Pheochromocytoma causes overproduction of catecholamines from the adrenal medulla, and the body converts these into metanephrines that stay elevated over time. Measuring 24-hour urinary metanephrines and catecholamines captures both the catecholamines and their metabolites, providing high sensitivity because these metabolites reflect tumor activity even if catecholamine release is episodic. This makes the test a classic, reliable way to screen for and support the diagnosis of pheochromocytoma. Prolactin is a pituitary hormone and would prompt evaluation for pituitary disorders, not pheochromocytoma, while serum sodium or calcium elevations are not characteristic diagnostic markers for this tumor.

Pheochromocytoma causes overproduction of catecholamines from the adrenal medulla, and the body converts these into metanephrines that stay elevated over time. Measuring 24-hour urinary metanephrines and catecholamines captures both the catecholamines and their metabolites, providing high sensitivity because these metabolites reflect tumor activity even if catecholamine release is episodic. This makes the test a classic, reliable way to screen for and support the diagnosis of pheochromocytoma. Prolactin is a pituitary hormone and would prompt evaluation for pituitary disorders, not pheochromocytoma, while serum sodium or calcium elevations are not characteristic diagnostic markers for this tumor.