As pheochromocytomas enlarge, they develop areas of hemorrhagic necrosis. Most pheochromocytomas >4 cm in diameter have some cystic component that is evident on computed cross-sectional imaging. Some pheochromocytomas become progressively cystic to the point that the radiologist interprets them as adrenal cysts. Such a case is reported herein.
The patient was a 50-year-old woman who presented with persistent and recurrent emesis that led to abdominal computed tomography (CT). Incidentally discovered on the CT scan was a 7 × 8.3–cm cystic right adrenal mass ( Fig. 43.1 ). The patient was morbidly obese (body mass index 51.6 kg/m 2 ). She had well-controlled hypertension of 7 years, duration that was treated with a β-adrenergic blocker (atenolol 100 mg daily) and an angiotensin receptor antagonist (valsartan 80 mg daily). She also had type 2 diabetes mellitus diagnosed 5 years previously and treated with metformin 500 mg once daily. Her blood pressure was 136/76 mmHg and heart rate was 76 beats per minute.
The plasma fractionated metanephrines and 24-hour urine for fractionated metanephrines and catecholamines unequivocally confirmed the diagnosis of pheochromocytoma ( Table 43.1 ).
|Biochemical Test||Result||Reference Range|
Glycosylated hemoglobin, %
Plasma metanephrine, nmol/L
Plasma normetanephrine, nmol/L
Plasma renin activity ng/mL per hour