Case Report: ACTH- and CRH-Secreting Pheochromocytoma as a Very Rare Cause of Ectopic Cushing Syndrome

This case report discusses a very rare instance of ectopic Cushing syndrome caused by a pheochromocytoma, a type of neuroendocrine tumor. Typically, pheochromocytomas are uncommon, and even more rare is their ability to produce ectopic hormones, occurring in less than 1% of cases. The report highlights an exceptional case where the pheochromocytoma exhibited co-expression of both adrenocorticotropic hormone (ACTH) and corticotropin-releasing hormone (CRH), leading to severe hypercortisolemia. This dual hormone secretion by the tumor is an unusual cause of ectopic ACTH syndrome (EAS).