Surgical treatment of pheochromocytomas.

Pheochromocytomas are tumors that develop from chromaffin tissue of the embryonic sympathoadrenal system. These tumors may occur anywhere chromaffin tissue exists but most often develop in the adrenal medulla. Less than 50% of patients are diagnosed with pheochromocytomas while alive, and most of these tumors are found on autopsy. The classic signs and symptoms of pheochromocytomas are headache, perspiration, palpitations, pallor, and paroxysmal hypertension. Elevated levels of vanillylmandelic acid and metanephrines in patients' 24-hour urine collections are the most reliable diagnostic indicators of pheochromocytomas. Most patients with pheochromocytomas can be cured if diagnoses and surgical resections of tumors occur before irreversible cardiovascular disease and end-organ damage from hypertension develop.