Rarely an autoantibody directed against the beta adrenergic receptor can result in a syndrome that can mimic pheochromocytoma.
The autoantibody binds to the beta adrenergic receptor, which activates the signal transduction system.
Clinical features:
(1) hypertension that is poorly controlled if beta blockers are not used
(2) clinical signs of beta adrenergic stimulation
(3) absence of alpha adrenergic stimulation
(4) variable presence of an autoimmune disorder, including autoimmune polyendocrinopathy
(5) cardiomyopathy with risk for arrhythmias
Laboratory findings:
(1) absence of an elevation in serum catecholamines
(2) no evidence of a tumor mass
(3) presence of an autoantibody directed against the beta adrenergic receptor