title: Pulmonary vasculopathy in idiopathic spontaneous pneumothorax in young subjects.
abstract: BACKGROUND
  We have encountered instances where young subjects with idiopathic spontaneous pneumothorax have been needlessly referred for investigation of pulmonary hypertension because surgical pathologists have misinterpreted the significance of medial hypertrophy and intimal fibrosis of muscular pulmonary arteries in lung resection specimens.
  
  
  METHODS
  We reviewed 20 cases of idiopathic spontaneous pneumothorax and determined the prevalence and severity of medial and intimal lesions in the pulmonary arteries and pulmonary veins. We correlated the vascular changes with inflammation and fibrosis in the lung.
  
  
  RESULTS
  Pulmonary artery medial hypertrophy was seen in 15% of cases, pulmonary artery intimal fibrosis in 90% of cases, and pulmonary vein intimal fibrosis in 80% of cases. In 95% of cases, the lung showed some fibrosis and chronic inflammation. There was a significant positive correlation between pulmonary artery medial thickness and lung fibrosis and inflammation scores.
  
  
  CONCLUSIONS
  Pulmonary artery medial hypertrophy and intimal fibrosis of pulmonary arteries and pulmonary veins are commonly seen in resected lung tissue from patients with idiopathic spontaneous pneumothorax. The vascular lesions are probably secondary to chronic inflammation and fibrosis in the adjacent lung. They are not clinically significant and do not represent hypertensive pulmonary vascular disease.
authors.affiliation: Department of Laboratory Medicine, St Joseph's Hospital, and the Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: P V
authors.initials: PV
authors.lastname: Cyr
authors.forename: L
authors.initials: L
authors.lastname: Vincic
authors.forename: J M
authors.initials: JM
authors.lastname: Kay
mesh_terms: D000293:Adolescent; D000328:Adult; D003251:Constriction, Pathologic / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000473:pathology; D007249:Inflammation / Q000150:complications* / Q000473:pathology; D008297:Male; D011030:Pneumothorax / Q000150:complications* / Q000473:pathology / Q000601:surgery; D011651:Pulmonary Artery / Q000473:pathology*; D011658:Pulmonary Fibrosis / Q000150:complications* / Q000473:pathology; D011668:Pulmonary Veno-Occlusive Disease / Q000150:complications / Q000473:pathology*