A 25-year-old woman presents to the emergency room complaining of headache, palpitations, and anxiety. She has had similar symptoms several times over the past 3 months. On physical examination her blood pressure is 210/120 mm Hg in both arms and she is noted to have an enlarged thyroid. Chest x-ray is within normal limits. Complete blood cell (CBC) count and chemistry profile are unremarkable.

The differential diagnosis of hypertensive crisis in a young woman includes essential hypertension, stimulant abuse, renal artery stenosis, hyperthyroidism, pre-eclampsia, and pheochromocytoma.

CBC, electrolytes, thyroid function tests, drug screen, pregnancy test, and CT scan of the abdomen.

The patient has a normal CBC and electrolytes, negative pregnancy test, normal thyroid functions (T₄ and TSH), and negative drug screen. CT of the abdomen shows a 7-cm cystic mass in the right adrenal. Plasma metanephrines are elevated. Twenty-four-hour urine normetanephrine is 30 nmol/L (normal is <1 nmol/L), 24-hour urine metanephrine is 5 nmol/L (normal is <0.5 nmol/L), and 24-hour urine epinephrine and norepinephrine are elevated as well.

Right adrenal pheochromocytoma. Adrenalectomy is recommended, with preoperative preparation with alpha-blockade. The presence of a pheochromocytoma coexisting with a thyroid mass raises the possibility of multiple endocrine neoplasia (MEN) type 2a with medullary thyroid carcinoma (MTC). Measurement of serum calcitonin level and fine-needle aspiration (FNA) cytology of the thyroid mass are recommended after removal of the pheochromocytoma.