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Question 23#

A 25-year-old woman is admitted for hypertensive crisis. The patient’s urine drug screen is negative. In the hospital, blood pressure is labile and responds poorly to antihypertensive therapy. The patient complains of palpitations and apprehension. Her past medical history shows that she developed hypertension during an operation for appendicitis at age 23.

Which of the following is the most likely diagnosis?

A. Panic attack
B. Renal artery stenosis
C. Essential hypertension
D. Type 1 diabetes mellitus
E. Pheochromocytoma

Correct Answer is E


Hypertensive crisis in this young woman suggests a secondary cause of hypertension. In the setting of palpitations, apprehension, and hyperglycemia, pheochromocytoma should be considered. Pheochromocytomas are derived from the adrenal medulla. They are capable of producing and secreting catecholamines. Unexplained hypertension associated with surgery or trauma may also suggest the disease. Clinical symptoms are the result of catecholamine secretion. For example, the patient’s hyperglycemia is a result of a catecholamine effect of insulin suppression and stimulation of hepatic glucose output. Hypercalcemia has been attributed to ectopic secretion of parathormone-related protein. Renal artery stenosis can cause severe hypertension but would not explain the systemic symptoms or laboratory abnormalities in this case. An anxiety attack can produce palpitations, apprehension, and mild to moderate elevation in blood pressure but would not produce hypercalcemia nor elevated blood pressure poorly responsive to treatment. Essential hypertension can occur in a 25-year-old but again would not account for the laboratory changes. Diabetes mellitus does not cause hypertension unless renal insufficiency has already developed; her hyperglycemia will likely resolve when the pheochromocytoma is removed. Once pheochromocytoma is suspected, a urine or plasma specimen for metanephrines or fractionated catecholamines is the commonly used diagnostic study. If a plasma sample is used, it is drawn from an indwelling IV catheter so that the pain of phlebotomy does not raise the catecholamine levels. After biochemical evidence of catecholamine overproduction is found, imaging studies (CT scan, radionuclide imaging) will localize the problem for curative surgery.