Case Presentation

A 38-year-old man complains of the recent onset of episodes of headache, nervousness, sweating, a racing heart, and rapid breathing. The episodes last from a few minutes to over an hour and occur several times a day. On physical examination his pulse is 86 beats/min, his respiration rate is 24/min, and his blood pressure is 210/110 mm Hg. The patient has no history of hypertension and is taking no medications. He is given oxygen and intravenous labetalol to gradually reduce heart rate and blood pressure. His 24-hour urinary vanillylmandelic acid concentration is 10.8 mg (normal <7 mg/24 hr), his epinephrine is elevated at 186 mcg (normal <22 mcg/24 hr), and norepinephrine is 135 mcg (normal 12 to 85 mcg/24 hr). A computed tomography image shows a 1.7 × 2.1 cm soft tissue density in the left suprarenal area but no other abnormalities, and he is placed on metoprolol to control high blood pressure until surgery, and phenoxybenzamine and metyrosine right before surgery. His blood pressure is gradually reduced to 118/65 mm Hg, and he is started on a high-salt diet to maintain plasma volume. A week later he undergoes laparoscopic left adrenalectomy and his medications are gradually withdrawn. His blood pressure stabilizes at 120/70 mm Hg, and he is discharged after an uneventful recovery with no discharge medication required.

Case Discussion

Pheochromocytoma is a rare tumor of the adrenal medulla that secretes huge quantities of epinephrine and norepinephrine. The peak age of onset is 40 years. Symptoms may be intermittent or continuous and include headache, anxiety, sweating, rapid breathing, and tachycardia. The diagnosis is established by abdominal imaging and measurement of urinary catecholamines and vanillylmandelic acid. If the tumor has not metastasized, it can be surgically removed with no sequelae. Blood pressure should be controlled until surgery with adrenoceptor antagonists, and phenoxybenzamine is often used for this purpose along with a β-blocker to reduce cardiac stimulation and prevent arrhythmias and cardiac ischemia. Alternatively, metyrosine (see Chapters 5 and 10) can be used with phenoxybenzamine to control blood pressure preoperatively, and the drug is useful in managing patients when surgery is contraindicated or when the tumor has metastasized. Patients are usually given a high-sodium diet (>5000 mg daily) to counteract catecholamine-induced volume contraction and the orthostatic hypotension caused by α-receptor blockade. If the tumor is unilateral, replacement of corticosteroids is not necessary after adrenalectomy.