title: A study of patients with isolated mediastinal and hilar lymphadenopathy undergoing EBUS-TBNA.
abstract: BACKGROUND
  Isolated mediastinal and/or hilar lymphadenopathy (IMHL) may be caused by benign and malignant disorders or be 'reactive'. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has a reported low negative predictive value (NPV) in IMHL, necessitating mediastinoscopy in selected patients. The aim of this study was to examine the NPV of EBUS-TBNA in an IMHL population and determine whether clinical variables differentiate between pathological and reactive IMHL.
  
  
  METHODS
  Analysis of a prospectively maintained database of consecutive patients with IMHL referred to a single UK centre for EBUS-TBNA.
  
  
  RESULTS
  100 patients with IMHL had EBUS-TBNA during the study (March 2010-February 2013), mean age 58.6±15.7 years, 63% men, 70% white British and mean follow-up 16.8±8.6 months. Pathological cause of IMHL established in 52 patients (sarcoidosis n=20, tuberculosis n=18, carcinoma n=7, lymphoma n=6, benign cyst n=1), 43 from EBUS-TBNA. 48/57 negative EBUS-TBNA samples were true negatives reflecting reactive lymphadenopathy in 48%. The diagnostic accuracy of EBUS-TBNA was 91% and NPV was 84.2% (95% CI 72.6% to 91.5%). Multivariate analysis of clinical covariates showed age (odds ratio (OR) 1.07, 95% CI 1.01 to 1.13; p=0.033), the presence of a relevant comorbidity (OR 9.49, 95% CI 2.20 to 41.04; p=0.003) and maximum lymph node size (OR 0.70, 95% CI 0.59 to 0.83; p=0.00004) to differentiate between reactive and pathological IMHL. Stratification of the study population according to comorbidity and maximum lymph node size (<20 mm) identified a low-risk cohort (n=32) where the NPV of EBUS-TBNA was 93.8% (95% CI 79.9% to 98.3%).
  
  
  CONCLUSIONS
  Reactive lymphadenopathy accounts for a significant proportion of patients with IMHL. In carefully selected patients with IMHL and a negative EBUS-TBNA, surveillance rather than further invasive sampling may be an appropriate strategy.
authors.affiliation: North West Lung Centre, University Hospital of South Manchester , Manchester , UK ; The Institute of Inflammation and Repair, The University of Manchester , Manchester , UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Evison
authors.affiliation: North West Lung Centre, University Hospital of South Manchester , Manchester , UK ; The Institute of Inflammation and Repair, The University of Manchester , Manchester , UK.
authors.forename: Philip A J
authors.initials: PA
authors.lastname: Crosbie
authors.affiliation: Department of Medical Statistics , University Hospital of South Manchester , Manchester , UK.
authors.forename: Julie
authors.initials: J
authors.lastname: Morris
authors.affiliation: North West Lung Centre, University Hospital of South Manchester , Manchester , UK.
authors.forename: Julie
authors.initials: J
authors.lastname: Martin
authors.affiliation: North West Lung Centre, University Hospital of South Manchester , Manchester , UK.
authors.forename: Philip V
authors.initials: PV
authors.lastname: Barber
authors.affiliation: North West Lung Centre, University Hospital of South Manchester , Manchester , UK ; The Institute of Inflammation and Repair, The University of Manchester , Manchester , UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Booton
keywords: Bronchoscopy; Lung Cancer; Sarcoidosis; Tuberculosis