title: Does 'idiopathic pleuritis' exist? Natural history of non-specific pleuritis diagnosed after thoracoscopy.
abstract: BACKGROUND
  Even after a complete work-up including thoracoscopic biopsies, a significant number of patients with pleural exudates are diagnosed with 'non-specific pleuritis', and no specific diagnosis can be made. The natural evolution of these patients is poorly understood.
  
  
  OBJECTIVE
  To study the natural evolution of patients with non-specific pleuritis diagnosed after thoracoscopy and to evaluate whether the histological diagnosis of non-specific pleuritis corresponds with the clinical diagnosis of 'idiopathic pleuritis'.
  
  
  METHODS
  We retrospectively studied the evolution of 75 patients between 1992 and 2002 (49 men and 26 women), mean (+/- SD) age 63.4 (+/- 13.3) years, who underwent diagnostic thoracoscopy because of an unexplained exudative pleural effusion, and in whom the histological diagnosis of non-specific pleuritis was made. Follow-up data were obtained through medical files and/or telephone contacts with general practitioners.
  
  
  RESULTS
  Of these 75 patients, 8.3% eventually developed a malignancy during the follow-up period. In the remaining patients (91.7%), the clinical evolution followed a benign course. Ultimately, a probable cause was established on clinical grounds in 40 patients. True idiopathic pleuritis was finally observed in 25% of patients with the histological diagnosis of non-specific pleuritis. Recurrence of the effusion occurred in 10 out of 60 (16.7%) patients, after a mean period of 26.2 months.
  
  
  CONCLUSIONS
  The majority of non-specific pleuritis patients (91.7%) followed a benign course, with a spontaneous resolution of the effusion in 81.8% of cases. In the majority of patients, a probable cause of the pleuritis was identified. True 'idiopathic benign pleuritis' hence occurs in only a minority (25%) of patients.
authors.affiliation: Interventional Endoscopy Clinic, Respiratory Division, Free University of Brussels, Brussels, Belgium.
authors.forename: L N
authors.initials: LN
authors.lastname: Venekamp
authors.forename: B
authors.initials: B
authors.lastname: Velkeniers
authors.forename: M
authors.initials: M
authors.lastname: Noppen
mesh_terms: D001706:Biopsy / Q000379:methods; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010994:Pleura / Q000473:pathology*; D010996:Pleural Effusion / Q000150:complications* / Q000473:pathology; D010998:Pleurisy / Q000209:etiology* / Q000473:pathology; D012008:Recurrence; D012189:Retrospective Studies; D013906:Thoracoscopy