title: A Clinical Classification Scheme for Tracheobronchomegaly (Mounier-Kuhn Syndrome).
abstract: BACKGROUND
  Tracheobronchomegaly (Mounier-Kuhn Syndrome) is a rare disease characterized by tracheal enlargement and associated loss of elastic fibers in the trachea and main bronchi.
  
  
  METHODS
  MEDLINE, Index Medicus, and other databases were searched with pre-defined criteria to identify cases of tracheobronchomegaly (TBM). Two new cases of TBM were also identified from the Provincial Medical Genetics Program of British Columbia.
  
  
  RESULTS
  We identified 166 publications describing 365 occurrences of TBM. We observed that affected individuals could be grouped into subgroups according to clinical features. Type 1A (105 individuals) consists of infants who developed TBM after having undergone fetoscopic tracheal occlusion, and Type 1B patients (24 individuals) are infants and children who developed TBM after prolonged intubation. Type 2 individuals developed TBM following recurrent pulmonary infections (2A) (14 individuals) or pulmonary fibrosis (2B) (10 individuals). Type 3 represents TBM with evidence of extra-pulmonary elastolysis (18 individuals), and Type 4 denotes the development of TBM with no clear predisposing factors (196 individuals). Both of our patients had TBM and evidence of extra-pulmonary elastolysis. As well, one patient had a mildly dilated aortic root, which is a previously unreported co-occurrence.
  
  
  CONCLUSIONS
  We introduce a novel classification scheme, which may sort patients into etiologically distinct groups, furthering our understanding of its pathogenesis and potentially, prevention or therapy. We also hypothesize that TBM and generalized elastolysis may have etiological commonalities, suggesting a need for further study.
authors.affiliation: Department of Medical Genetics, University of British Columbia, C234-4500 Oak Street, Vancouver, BC, V6H 3N1, Canada.|Child and Family Research Institute, Vancouver, BC, Canada.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Payandeh
authors.affiliation: Department of Medical Genetics, University of British Columbia, C234-4500 Oak Street, Vancouver, BC, V6H 3N1, Canada.|Child and Family Research Institute, Vancouver, BC, Canada.
authors.forename: Barbara
authors.initials: B
authors.lastname: McGillivray
authors.affiliation: Division of Respirology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Graeme
authors.initials: G
authors.lastname: McCauley
authors.affiliation: Division of Respirology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Pearce
authors.initials: P
authors.lastname: Wilcox
authors.affiliation: Division of Respirology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: John R
authors.initials: JR
authors.lastname: Swiston
authors.affiliation: Department of Medical Genetics, University of British Columbia, C234-4500 Oak Street, Vancouver, BC, V6H 3N1, Canada. alehman@cw.bc.ca.|Child and Family Research Institute, Vancouver, BC, Canada. alehman@cw.bc.ca.
authors.forename: Anna
authors.initials: A
authors.lastname: Lehman
mesh_terms: D003483:Cutis Laxa / Q000150:complications; D005332:Fetoscopy / Q000009:adverse effects; D006801:Humans; D007223:Infant; D007442:Intubation, Intratracheal / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000150:complications; D012141:Respiratory Tract Infections / Q000150:complications; D014137:Tracheobronchomegaly / Q000145:classification* / Q000209:etiology*
keywords: Acquired cutis laxa; Connective tissue diseases; Generalized elastolysis; Mounier-Kuhn syndrome; Tracheobronchomegaly