Q. A 45-year-old male is brought to the emergency department complaining of a severe headache and difficulty breathing. The patient reports a history of hypertension for the past 5 years, which is managed with multiple medications including a diuretic, an ACE inhibitor, and a calcium channel blocker. Despite the use of these medications, the patient's blood pressure has remained elevated, with readings consistently reported in the range of 170/110 mm Hg. Upon arrival to the emergency department, the patient's blood pressure is measured and found to be 182/110 mm Hg. The patient is also noted to have a serum potassium level of 3.1 mEq/L. Given the patient's history of resistant hypertension and serum potassium levels, you are concerned for hyperaldosteronism and order a plasma renin activity test to assess the patient’s levels of renin. You also order a CT scan of his adrenal glands. You treat him with intravenous fluids and medications to lower his blood pressure and stabilize his condition. Based on the information you have at this point in time, which of the following is the LEAST likely cause of this patient’s symptoms?