title: A unique, histopathologic lesion in a subset of patients with spontaneous pneumothorax.
abstract: BACKGROUND
  Spontaneous pneumothorax can be idiopathic (primary), or it can occur in association with an underlying predisposing condition (secondary). Spontaneous pneumothorax may be a harbinger of an undiagnosed clinical condition, which may be associated with serious systemic abnormalities, making early recognition and diagnosis important. The pulmonary pathology of some of these disorders has not been fully elucidated.
  
  
  OBJECTIVE
  To review cases of pneumothorax in the hope of identifying pathologic features that might correlate to specific clinical syndromes.
  
  
  METHODS
  The pathology computer files at 3 hospitals were searched for all cases of spontaneous pneumothorax, primary and secondary, regardless of etiology during a 11-year period. Ninety-two cases were retrieved. Each of the cases was evaluated for reactive eosinophilic pleuritis, elastosis, pleural fibrosis, emphysema, intra-alveolar macrophages, cholesterol clefts, vasculopathy, and intraparenchymal or intrapleural cysts. Clinical information regarding asthma and smoking history, site of the pneumothorax, family history, radiographic findings, predisposing conditions, recurrence, age, and sex were extracted from the medical records.
  
  
  RESULTS
  In 11 patients (12% of all the patients with spontaneous pneumothorax), a distinctive pattern of pleural fibrosis with islands of fibroblastic foci within a myxoid stroma was noted at the pleural-parenchymal interface or leading edge. These lesions correlated with a select subset of patients, consisting predominantly of young men.
  
  
  CONCLUSIONS
  Our review identified a distinct pattern of pneumothorax-associated fibroblastic lesions in a subset of cases of spontaneous pneumothorax. Whether this is related to the pathogenesis of the pneumothorax remains to be elucidated.
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. dbelchi1@jhmi.edu
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Belchis
authors.forename: Kris
authors.initials: K
authors.lastname: Shekitka
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Gocke
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D015142:Baltimore; D001768:Blister / Q000150:complications / Q000175:diagnosis / Q000276:immunology / Q000473:pathology / Q000503:physiopathology; D003238:Connective Tissue / Q000473:pathology; D057286:Electronic Health Records; D005260:Female; D006786:Hospitals, Urban; D006801:Humans; D008297:Male; D008875:Middle Aged; D010998:Pleurisy / Q000209:etiology; D011030:Pneumothorax / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology* / Q000503:physiopathology; D011657:Pulmonary Eosinophilia / Q000209:etiology; D011658:Pulmonary Fibrosis / Q000209:etiology; D012189:Retrospective Studies; D017678:Sex Distribution; D013577:Syndrome; D055815:Young Adult