Based on clinical findings (hypertension, polyuria,
polydipsia, fatigue, tinnitus, paresthesia, paralysis of variable duration,
failure to thrive, muscle loss). Hypokalemia (<3.5 mmol/liter; present in
approximately 20% of patients), metabolic alkalosis associated with
inappropriate kaliuresis, increased plasma levels of aldosterone
(>40 ng/dl), decreased plasma renin activity (<0.3 ng/ml/hour), nonsuppressible
aldosterone response to ambulation, and a pathologic fludrocortisone suppression test
confirm the diagnosis. Dexamethasone does not suppress aldosterone levels
(except in familial hyperaldosteronism, where small doses of dexamethasone
are used therapeutically). Magnetic resonance imaging is the diagnostic
imaging tool of choice. It shows that the adrenal gland on the left side is
involved four times more often than the gland on the right.