title: Cushing's syndrome in a patient with a corticotropin-releasing hormone-producing pheochromocytoma.
abstract: OBJECTIVE
  To present the first case of Cushing's syndrome attributable solely to ectopic production of corticotropin-releasing hormone by a pheochromocytoma.
  
  
  METHODS
  We summarize the clinical features and results of laboratory investigations in a patient with symptoms characteristic of Cushing's syndrome.
  
  
  RESULTS
  Although Cushing's syndrome is usually caused by ectopic production of adrenocorticotropic hormone (ACTH), our current patient had clinical and biochemical evidence of hypercortisolism in conjunction with "normal" ACTH levels and nonsuppressible serum and urinary cortisol levels on low-dose and high-dose dexamethasone suppression testing. An abdominal computed tomographic scan revealed a 7.7-cm mass in the left adrenal gland. Light microscopic examination and immunohistochemical staining showed a pheochromocytoma with mild cortical hyperplasia. Immunostaining was positive for corticotropin-releasing hormone but negative for ACTH.
  
  
  CONCLUSIONS
  To our knowledge, this is the first case of Cushing's syndrome in a patient with pheochromocytoma caused only by ectopic secretion of corticotropin-releasing hormone without accompanying secretion of ACTH.
authors.affiliation: Department of Endocrinology, Singapore General Hospital, Singapore.
authors.forename: P H
authors.initials: PH
authors.lastname: Eng
authors.forename: L H
authors.initials: LH
authors.lastname: Tan
authors.forename: K S
authors.initials: KS
authors.lastname: Wong
authors.forename: C W
authors.initials: CW
authors.lastname: Cheng
authors.forename: A C
authors.initials: AC
authors.lastname: Fok
authors.forename: D H
authors.initials: DH
authors.lastname: Khoo