Pheochromocytoma: new concepts and future trends.

A 37-year-old white woman was referred to the Cleveland Clinic Foundation for evaluation of a right suprarenal mass. BeginningS years before, she had experienced episodes of severe headache, pounding heart, and flushing, followed by facial pallor and tremulousness. Neither blood pressure nor heart rate was checked during these spells. The attacks occurred about twice monthly and lasted for 5 to 20 minutes. She noted that "bearing down" during defecation or "curling up" on her left side often precipitated these episodes. She consulted 6 physicians over the subsequent 4 years; no diagnosis was made to explain her symptoms. One year ago, she consulted a neurologist, who performed a thorough examination and obtained a magnetic resonance image of the head: no abnormalities were detected. One month before she came to the Cleveland Clinic, her private physician obtained an abdominal sonogram because he suspected an abdominal aneurysm. The study revealed a "5.2 x 5.1 cm solid, hyperechoic suprarenal mass" on the right side. Neither she or her family had a significant medical history. Physical examination revealed a blood pressure of 122/76 mm Hg: pulse, 80 beats/mm and regular: and respiratory rate, 16/mm. The rest of the examination was unremarkable. Laboratory studies revealed: normal SMA-l6 values except for a blood glucose of 133 mg/dl: normal thyroid function: serum calcium. 8.8 mg/dl; plasma norepinephrine. 1456 pg/mI: epinephrine. 259 pg/mI; 24-hr urinary metanephrine, 5728 g/24 hr: normetanephrine, 10,465 g/24 hr; and serum chromogranin A, 162 ng/ml (normal. 50 ng/ml). An abdominal CT scan revealed a right suprarenal mass measuring about 6.0 cm diameter, which demonstrated a high signal intensity on the T2-weighted image by MRI (Fig. I). The mass concentrated high