title: How early can one diagnose Cushing's disease? An early diagnosis in a case of prepubertal Cushing's disease.
abstract: BACKGROUND
  Cushing's disease is very rare in children, and the diagnosis is frequently delayed by several years.
  
  
  OBJECTIVE
  We report a case of prepubertal Cushing's disease with a medical history of only 9 months. This case illustrates the difficulties involved in diagnosing children at the early stage of the disease.
  
  
  METHODS
  An 8-year-old prepubertal boy presented with rapid weight gain accompanied by a decreasing growth velocity and hirsutism. Thyroid function tests and growth factor levels were normal, thus excluding hypothyroidism and growth hormone deficiency. Cushing's syndrome was confirmed by elevated 24-h urinary free cortisol levels, increased diurnal cortisol levels, and a lack of cortisol suppression in the low-dose dexamethasone suppression test. Further tests to investigate the source of the hypercortisolism showed the following results: Basal morning adrenocorticotropic hormone (ACTH) was normal. The high-dose dexamethasone suppression test led to a 51% decrease in cortisol level. In the corticotropin-releasing hormone (CRH) test, ACTH and cortisol increased only by 28%. Repeated magnetic resonance imaging (MRI) finally revealed a microadenoma in the anterior pituitary, thus establishng the diagnosis of Cushing's disease. Upon diagnosis, the patient underwent transsphenoidal surgery. Histological analysis confirmed an ACTH-secreting pituitary adenoma.
  
  
  CONCLUSIONS
  This case illustrates the difficulties associated with the clinical, biochemical, and radiological diagnoses of Cushing's disease in children. Early diagnosis remains a challenge because test results often do not match standard diagnostic criteria.
authors.forename: Julia
authors.initials: J
authors.lastname: Hoppmann
authors.forename: Isabel V
authors.initials: IV
authors.lastname: Wagner
authors.forename: Gudrun
authors.initials: G
authors.lastname: Junghans
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Wudy
authors.forename: Michael
authors.initials: M
authors.lastname: Buchfelder
authors.forename: Franz W
authors.initials: FW
authors.lastname: Hirsch
authors.forename: Lutz
authors.initials: L
authors.lastname: Ritter
authors.forename: Wieland
authors.initials: W
authors.lastname: Kiess
authors.forename: Roland
authors.initials: R
authors.lastname: Pfäffle
mesh_terms: D049913:ACTH-Secreting Pituitary Adenoma / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D000236:Adenoma / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D000324:Adrenocorticotropic Hormone / Q000097:blood; D002648:Child; D003346:Corticotropin-Releasing Hormone / Q000097:blood; D003480:Cushing Syndrome / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D042241:Early Diagnosis; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008279:Magnetic Resonance Imaging; D008297:Male; D011627:Puberty
chemical_list: D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D006854:Hydrocortisone