title: A review of congenital lung malformations with a simplified classification system for clinical and research use.
abstract: OBJECTIVE
  Congenital lung abnormalities are rare malformations increasingly detected early by prenatal ultrasound. Whether management of these frequently asymptomatic lesions should be surgical or conservative is an unresolved issue. The necessary prospective studies are limited by the absence of a widely accepted practical classification system. Our aim was to develop a simple, clinically relevant system for classifying and studying congenital lung abnormalities.
  
  
  METHODS
  We based our proposed grouping on a detailed analysis of clinical, radiological, and histological data from well-documented cases, plus an extensive review of the literature.
  
  
  RESULTS
  The existence of hybrid lesions and common histological findings suggested a unified embryological mechanism-possibly obstruction of developing airways with distal dysplasia. Malformations could be classified by their anatomical and pathological findings; however, a system based on the prenatal ultrasound plus initial chest X-ray findings had greater clinical relevance: Group 1-Congenital solid/cystic lung malformation, Group 2-Congenital hyperlucent lobe, Group 3-Congenital small lung.
  
  
  CONCLUSIONS
  Pathological classification is academically important but is unnecessarily complex for clinical and research use. Our simple radiological-based system allows unambiguous comparison between the results of different studies and also guides the choice of necessary investigations specific to each group.
authors.affiliation: Divisions of Respiratory Medicine, British Columbia's Children's Hospital, Room 1C 31, 4480 Oak Street, Vancouver, BC, V6H 3V4, Canada. mseear@cw.bc.ca.
authors.forename: Michael
authors.initials: M
authors.lastname: Seear
authors.affiliation: Divisions of Respiratory Medicine, British Columbia's Children's Hospital, Room 1C 31, 4480 Oak Street, Vancouver, BC, V6H 3V4, Canada.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Townsend
authors.affiliation: Divisions of Respiratory Medicine, British Columbia's Children's Hospital, Room 1C 31, 4480 Oak Street, Vancouver, BC, V6H 3V4, Canada.
authors.forename: Amy
authors.initials: A
authors.lastname: Hoepker
authors.affiliation: Divisions of Radiology, British Columbia's Children's Hospital, Vancouver, Canada.
authors.forename: Douglas
authors.initials: D
authors.lastname: Jamieson
authors.affiliation: Divisions of Pathology, British Columbia's Children's Hospital, Vancouver, Canada.
authors.forename: Deborah
authors.initials: D
authors.lastname: McFadden
authors.affiliation: Division of Pediatric Respirology, Centre Mere-Enfant du CHUQ, Universite Laval, Quebec, Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: Daigneault
authors.affiliation: Division of Pediatric Pulmonology, University of Texas Medical Branch, Austin, USA.
authors.forename: William
authors.initials: W
authors.lastname: Glomb
mesh_terms: D035843:Biomedical Research; D006801:Humans; D008168:Lung / Q000002:abnormalities*; D008171:Lung Diseases / Q000145:classification* / Q000151:congenital*; D015619:Respiratory System Abnormalities / Q000145:classification*
keywords: Congenital lobar emphysema; Congenital lung malformations; Cystic adenomatoid malformation; Hypoplastic lung; Sequestration