title: Comparative study of ex vivo probe-based confocal laser endomicroscopy and light microscopy in lung cancer diagnostics.
abstract: OBJECTIVE
  Probe-based confocal laser endoscopy (pCLE) allows for real-time non-invasive histological imaging via bronchoscopy. Interpreting CLE images and correlating with traditional histopathology remains challenging. We performed an ex vivo study to evaluate the correlation between light microscopy findings and pCLE imaging of primary lung carcinoma.
  
  
  METHODS
  Post-lobectomy specimens for lung cancer nodules were examined ex vivo by pCLE. The examined areas were marked with brilliant green dye, and the surrounding tissues were stained by methylene blue dye. Lung tissue segments were resected and histopathological specimens were generated with 50-μm thickness from the marked areas and stained with haematoxylin and eosin. Pathologists and pulmonologists reviewed the images for correlating features.
  
  
  RESULTS
  Eighteen lobectomy specimens from 18 different patients were collected. Three primary features were observed in all samples using pCLE in the cancer surroundings: alveolar dystelectasis with thickening of alveolar walls, alveolar edema and a large amount of macrophages. The stromal and parenchymal components of the studied subtypes of non-small-cell lung cancer differed from each other. The stromal component for all nine adenocarcinoma specimens had a highly fluorescent field penetrated by dark hollows. All six squamous cell carcinoma specimens had the stromal component appeared as 'biparously' branching, highly fluorescent fibres. No stromal component was observed in any small-cell carcinoma specimen, and at low power field, the cellular component was dominant with an observed light scattering pattern.
  
  
  CONCLUSIONS
  pCLE can identify lung carcinoma in ex vivo samples. Certain light microscopy features of lung carcinoma can be visualized with pCLE.
authors.affiliation: Department of Pathology, Federal Research Clinical Center under FMBA of Russia, Moscow, Russia.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Sorokina
authors.forename: Olesya
authors.initials: O
authors.lastname: Danilevskaya
authors.forename: Alexander
authors.initials: A
authors.lastname: Averyanov
authors.forename: Fedor
authors.initials: F
authors.lastname: Zabozlaev
authors.forename: Dmitry
authors.initials: D
authors.lastname: Sazonov
authors.forename: Lonny
authors.initials: L
authors.lastname: Yarmus
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000473:pathology; D000368:Aged; D001706:Biopsy; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology / Q000601:surgery; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008853:Microscopy / Q000379:methods*; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged; D011013:Pneumonectomy; D015203:Reproducibility of Results
keywords: bronchoscopy; ex vivo confocal laser endomicroscopy; histology; light microscopy; lung cancer