title: Pulmonary arterial sampling was useful for localizing ectopic ACTH production in a patient with bronchial carcinoid causing Cushing syndrome.
abstract: OBJECTIVE
  We report a 44-year old man with ectopic adrenocorticotropic hormone (ACTH) syndrome caused by bronchial carcinoid that developed Cushing syndrome.
  
  
  METHODS
  We performed several imaging studies, including chest and abdominal CT, for exploration of nodules and selective pulmonary arterial sampling for localizing a source of ectopic ACTH production.
  
  
  RESULTS
  The patient was diagnosed as Cushing syndrome due to ectopic production of ACTH without identification of its source(s). After 2 years' follow-up with repeated CT scans every 6-12 months and treatment with metyrapone, chest CT revealed two small nodules respectively in the segment (S) 4 and 10 of the right lung. We performed selective pulmonary arterial sampling from branches of the right pulmonary artery to obtain blood from the nodules in a reverse flow fashion: wedged sampling from the basal branch (A8, 9 and 10) revealed significant elevation of ACTH, whereas sampling from the lateral branch (A4) did not, indicating that the S10 nodule produced ACTH ectopically. The video-assisted thoracoscopic surgery removing the right inferior lobe normalized plasma ACTH, serum cortisol and 24-hour urinary free cortisol. The S10 nodule was histologically diagnosed as atypical bronchial carcinoid containing immunoreactive ACTH.
  
  
  CONCLUSIONS
  Selective pulmonary arterial sampling was useful for localizing the lesion of ectopic ACTH production and helped make the decision for its surgical removal. This procedure should be considered once lung nodules suspicious for ectopic ACTH production are identified in patients with EAS.
authors.affiliation: Endocrinology & Diabetes Center, Yokohama Rosai Hospital, Yokohama, Japan.
authors.forename: Ikki
authors.initials: I
authors.lastname: Sakuma
authors.forename: Jun
authors.initials: J
authors.lastname: Saito
authors.forename: Yoko
authors.initials: Y
authors.lastname: Matsuzawa
authors.forename: Masao
authors.initials: M
authors.lastname: Omura
authors.forename: Seiji
authors.initials: S
authors.lastname: Matsui
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Maehara
authors.forename: Naoki
authors.initials: N
authors.lastname: Hasegawa
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nishikawa
mesh_terms: D000182:ACTH Syndrome, Ectopic / Q000175:diagnosis*; D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D001984:Bronchial Neoplasms / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D002276:Carcinoid Tumor / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D003480:Cushing Syndrome / Q000209:etiology*; D006801:Humans; D008297:Male; D011651:Pulmonary Artery
chemical_list: D000324:Adrenocorticotropic Hormone