Abstract
Pheochromocytoma may present as either the classic catecholaminergic phenotype or as one of many kinds of peptidergic phenotypes, including’s Cushing syndrome, watery diarrhea, hypokalemia, and achlorhydria syndrome (WDHA), acromegaly, or humoral hypercalcemia, or a combination of both phenotypes. Cushing’s syndrome may be caused by a pheochromocytoma producing adrenocorticotropic hormone (ACTH) or one producing corticotropin-releasing hormone (CRH). WDHA can be caused by a pheochromocytoma producing vasoactive intestinal peptide (VIP). Acromegaly may be due to a pheochromocytoma producing growth hormone-releasing hormone (GHRH). Humoral hypercalcemia can be due to a pheochromocytoma producing parathyroid hormone-related peptide (PTHrP). -These findings strongly suggest that pheochromocytomas can produce and secrete many kinds of peptide hormones, reinforcing the multisecretory nature of chromaffin cells.
Knowledge of the clinical diversity of pheochromocytomas is important for both precise diagnosis and proper management. Complex clinical features among these cases may lead to the wrong diagnosis, such as an atypical overlap syndrome of multiple endocrine neoplasias. In the case of ectopic GHRH syndrome, unnecessary pituitary surgery may be performed because catecholaminergic features are scanty among patients with this syndrome.