title: Neuroendocrine cell distribution and frequency distinguish neuroendocrine cell hyperplasia of infancy from other pulmonary disorders.
abstract: BACKGROUND
  The diagnostic gold standard for neuroendocrine cell hyperplasia of infancy (NEHI) is demonstration of increased numbers of neuroendocrine cells (NECs) amid otherwise near-normal lung histology. Typical clinical and radiographic features often are present. However, NECs are also increased after lung injury and in other disorders, which can complicate biopsy specimen interpretation and diagnosis of suspected NEHI. Our objective was to determine whether NEC prominence is specific for the diagnosis of NEHI.
  
  
  METHODS
  Bombesin immunoreactivity was quantified in lung biopsy specimens from 13 children with characteristic clinical presentation and imaging appearance of NEHI. The primary comparison group was 13 age-matched patients selected from children with lung disorders that are known to be associated with NEC prominence.
  
  
  RESULTS
  Bombesin-immunopositive epithelial area was significantly increased in NEHI compared with other diseases. Patchy bronchiolar inflammation or fibrosis was frequently observed in NEHI, with no direct association between airway histopathology and bombesin-immunopositive area. NEC prominence correlated with severity of small airway obstruction demonstrated on infant pulmonary function testing. Immunohistochemical colocalization of bombesin with Ki67 did not reveal active NEC proliferation. There was wide intra- and intersubject variability in NEC number, which did not relate to radiographic appearance of the region biopsied.
  
  
  CONCLUSIONS
  Our findings demonstrate that NEC prominence is a distinguishing feature of NEHI independent of airway injury. The extent of intrasubject variability and potential for overlap with control subjects suggest that clinical-radiologic-pathologic correlation is required for diagnosis and that the abundance of NECs may not fully explain the disease pathogenesis.
authors.affiliation: Division of Pulmonary Medicine, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH.
authors.forename: Lisa R
authors.initials: LR
authors.lastname: Young
authors.affiliation: Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH.
authors.forename: Alan S
authors.initials: AS
authors.lastname: Brody
authors.affiliation: Department of Surgery, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Inge
authors.affiliation: Division of Pulmonary Medicine, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH.
authors.forename: James D
authors.initials: JD
authors.lastname: Acton
authors.affiliation: Division of Pulmonary Medicine, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH.
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Bokulic
authors.affiliation: Department of Pathology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX.
authors.forename: Claire
authors.initials: C
authors.lastname: Langston
authors.affiliation: Department of Laboratories, Seattle Children's Hospital, University of Washington, Seattle, WA. Electronic address: gail.deutsch@seattlechildrens.org.
authors.forename: Gail H
authors.initials: GH
authors.lastname: Deutsch
mesh_terms: D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007223:Infant; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D055099:Neuroendocrine Cells / Q000473:pathology*; D011859:Radiography