Three Cases of ACTH-Producing Pheochromocytoma – Full Hormonal Workup in Patients With an Adrenal Mass May Be Crucial For Correct Management

ABSTRACT Objective: In rare cases, adrenal medullary tumors secrete adrenocorticotropic hormone (ACTH) in addition to catecholamines. Methods: We present 3 cases of ACTH-producing pheochromocytomas, highlighting the diagnostic challenges, clinical severity, and phenotypic diversity of this rare phenomenon. Results: Two of the patients (females aged 75 and 60 years) presented with typical Cushingoid phenotypes. Their biochemical profiles were consistent with ectopic ACTH-dependent Cushing syndrome with grossly elevated plasma ACTH and urinary free cortisol. One of the patients had vague symptoms of adrenergic hyperactivity and highly elevated levels of plasma metanephrines, whereas the other had no symptoms of pheochromocytoma. The third patient (male aged 64 years) presented with tachycardia, labile blood pressure, and sweating consistent with pheochromocytoma. He had no signs of Cushing syndrome. Plasma and urine samples showed highly elevated concentrations of catecholamines, ACTH, and cortisol. After admission to hospital, all patients deteriorated within a few weeks with multiorgan involvement. All 3 had unilateral adrenal masses, and acute rescue adrenalectomy was performed. Histopathologic examination showed pheochromocytomas with positive ACTH immunostaining. The patients recovered quickly after surgery with restoration of organ functions. Conclusion: Extensive hormone profile evaluations should be carried out in all adult patients presenting with an adrenal mass independent of the clinical presentation. ACTH-producing pheochromocytoma should be considered in patients presenting with the confusing picture of ACTH-dependent Cushing syndrome and a unilateral adrenal mass. Abbreviations: ACTH adrenocorticotropic hormone CT computed tomography MRI magnetic resonance imaging P plasma T2DM type 2 diabetes mellitus