title: Cell block samples from endobronchial ultrasound transbronchial needle aspiration provide sufficient material for ancillary testing in lung cancer-a quaternary referral centre experience.
abstract: BACKGROUND
  Rapid on site examination (ROSE) is encouraged at endobronchial ultrasound transbronchial needles aspiration (EBUS-TBNA) to improve diagnostic yield. Due to new therapeutic options in lung cancer, it is not sufficient to merely distinguish between non-small cell lung carcinoma (NSCLC) and small cell lung carcinoma (SCLC). Immunohistochemistry (IHC) distinction is now standard practice, as well as additional molecular testing where clinically indicated. We investigated the diagnostic yield of on-site smearsvs. cell block and the provision of cellular material for ancillary testing at our centre.
  
  
  METHODS
  A retrospective audit of all EBUS-TBNA procedures performed until July 2012 was undertaken. Diagnostic yield on smears versus cell block was recorded. Cell blocks were reviewed by an experienced pathologist to determine diagnostic accuracy and whether IHC and molecular testing were possible.
  
  
  RESULTS
  In total, 234 procedures were recorded with 101 (43.2%) malignant cases, 107 (45.7%) benign cases and an initial 26/234 (11.1%) insufficient for diagnosis of which 11/234 (4.7%) were false negatives for malignancy after further follow up. The average number of passes was 4.5. For malignancies, smear diagnosis was possible in 95% (96/101) of cases and cell block diagnosis in 93.5% (87/93) of cases. There was sufficient material for IHC in 97.7% (85/87) of malignant cases. In 79.3% (69/87) of NSCLCs molecular testing for epidermal growth factor receptor (EGFR) mutation analysis was theoretically possible on samples obtained.
  
  
  CONCLUSIONS
  Cell blocks are not inferior to smears for diagnostic accuracy and provide sufficient samples for histology. However, ROSE assists the physician on how best to manage samples for ancillary testing.
authors.affiliation: The Department of Thoracic Medicine, The Royal Adelaide Hospital, Adelaide 5000, Australia;; The University of Adelaide, Adelaide 5000, Australia.
authors.forename: Emily
authors.initials: E
authors.lastname: Hopkins
authors.affiliation: The Department of Surgical Pathology/Cytopathology, SA Pathology, SA 5000, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Moffat
authors.affiliation: The University of Adelaide, Adelaide 5000, Australia;; The Department of Anatomical Pathology, SA Pathology, SA 5000, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Parkinson
authors.affiliation: The Department of Thoracic Medicine, The Royal Adelaide Hospital, Adelaide 5000, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Robinson
authors.affiliation: The Department of Thoracic Medicine, The Royal Adelaide Hospital, Adelaide 5000, Australia;; The University of Adelaide, Adelaide 5000, Australia.
authors.forename: Hubertus
authors.initials: H
authors.lastname: Jersmann
authors.affiliation: The Department of Thoracic Medicine, The Royal Adelaide Hospital, Adelaide 5000, Australia.
authors.forename: Brendan
authors.initials: B
authors.lastname: Dougherty
authors.affiliation: The Department of Thoracic Medicine, The Royal Adelaide Hospital, Adelaide 5000, Australia.
authors.forename: Mohammed I
authors.initials: MI
authors.lastname: Birader
authors.affiliation: The Department of Surgical Pathology/Cytopathology, SA Pathology, SA 5000, Australia.
authors.forename: Kate
authors.initials: K
authors.lastname: Francis
authors.affiliation: The Department of Thoracic Medicine, The Royal Adelaide Hospital, Adelaide 5000, Australia;; The University of Adelaide, Adelaide 5000, Australia.
authors.forename: Phan
authors.initials: P
authors.lastname: Nguyen
keywords: Lung neoplasms; bronchoscopy; cell block; epidermal growth factor receptor gene (EGFR gene); molecular