title: Diagnostic Gain from Surgical Biopsy for Interstitial Lung Disease - When is it Worth the Risk?
abstract: BACKGROUND
  History, clinical presentation, lung function testing, radiographs including HRCT and nonsurgical biopsy techniques in most cases provide sufficient information for classification of interstitial lung disease (ILD). However, in a small percentage it is not possible to establish the diagnosis so that lung biopsy may be required. We analyzed under which circumstances a reduction of invasive procedures is reasonable.
  
  
  METHODS
  Between January 1997 and December 2009 we examined 3399 specimens from 1299 patients with benign inflammatory and granulomatous diseases in whom ILD was clinically hypothesized. We compared the probability of disease according to Bayes before and after surgery which corresponds to the clinical diagnosis (a priori probability) and the final diagnosis (a posteriori probability). Additionally, procedures, operation related complications and the patients' smoking habits were documented.
  
  
  RESULTS
  In 111 patients (8.5 %) surgical evaluation was performed (14 mediastinoscopies, 97 thoracotomies/VATS biopsies). All mediastinoscopies substantiated a epitheloid cell granulomatosis. In 30 % of all VATS procedures a prolonged air leak of more than 4 days was observed. One patient died and one had to get a new chest tube after removal. Changes of a priori/a posteriori probabilities was shown for non-smokers in Wegner's granulomatosis (0.6 vs. 2.2 %) and IPF (16.7 vs. 34.8 %), for smokers in Langerhans' cell histiocytosis (1.4 vs. 7.8 %) and IPF (16.7 vs. 33.3 %). In the majority of cases even a reduction of probability was seen.
  
  
  CONCLUSIONS
  Considering complications and limited diagnostic gain, lung biopsies for diagnosis of ILD should be recommended only in selected patients.
authors.affiliation: Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Biancosino
authors.affiliation: Lung Clinic Grosshansdorf, Center for Pneumology and Thoracic Surgery, Grosshansdorf, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Welker
authors.affiliation: Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Krüger
authors.affiliation: Department of Thoracic Surgery, Helios Klinikum Wuppertal, University Hospital Witten/Herdecke, Wuppertal, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Bölükbas
authors.affiliation: Institute of Pathology, Clinic Rotenburg, Rotenburg, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Bittmann
authors.affiliation: Lung Clinic Grosshansdorf, Center for Pneumology and Thoracic Surgery, Grosshansdorf, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Kirsten
mesh_terms: D001706:Biopsy / Q000379:methods*; D019317:Evidence-Based Medicine; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity