Pheochromocytoma : Diagnostic Tests
A solid brown tumor with cystic and hemorrhagic areas replaces most of the adrenal gland. Histopathology showed features of a typical pheochromocytoma. Clinically, pheochromocytomas are a rare cause of surgically correctable hypertension. Paroxysmal hypertension and palpitations are seen in close to 90% of cases and are linked to the synthesis of catecholamines (epinephrine & norepinephrine) by the tumor cells. Patients clinically suspected of having pheochromocytoma undergo biochemical testing as the first line of evaluation. Urinary levels of catecholamines and their metabolites vanilylmandelic acid and total metanephrines are elevated and can be diagnostic. If metabolic tests are positive, imaging studies are undertaken to locate the source of excess catecholamines. Abdominal CT scan is currently the diagnostic modality of choice.