title: Proximal bronchial extension with special reference to tumor localization in non-small cell lung cancer.
abstract: OBJECTIVE
  Surgery is the optimal treatment in patients with non-small cell lung cancer (NSCLC) and tumor-negative bronchial resection margins should be maintained for a curative resection. The epidemiology of NSCLC, including the aspects of tumor localization, has been changing during the recent decades. The aim of this study was to evaluate microscopic proximal bronchial extension with special reference to the site of the tumor.
  
  
  METHODS
  Surgical specimens of 70 NSCLC cases were examined histologically for proximal bronchial extension of the tumor. The entire bronchial tree with the tumor was extracted from the specimen and serially cut at a thickness of 5 mm in the transverse plane of the bronchus. Microscopic proximal extension of the tumor was classified as either endobronchial or peribronchial.
  
  
  RESULTS
  Thirty-three (47.1%) tumors had central and 37 (52.9%) had peripheral localization. Among the central and peripheral tumors, 10 (30.3%) and seven (18.9%) had microscopic proximal extension, respectively. In total, the mean length of proximal extension was 10.94 +/- 7.07 mm. The mean length of extension for peripheral tumors was 15.71 +/- 8.38 mm, significantly greater than that of central tumors, which was 7.60 +/- 3.47 mm (P = 0.026). Peripheral tumors showed a significant peribronchial extension (P = 0.024).
  
  
  CONCLUSIONS
  A greater percentage of central tumors show microscopic proximal bronchial extension, whereas the length of microscopic proximal bronchial extension is significantly greater in peripheral tumors. Peripheral tumors preferentially have a peribronchial extension pattern.
authors.affiliation: Department of Thoracic Surgery, Ankara University School of Medicine, Ibn-i Sina Hospital, 06100 Sihhiye, Ankara, Turkey. muratkara66@hotmail.com
authors.forename: M
authors.initials: M
authors.lastname: Kara
authors.forename: S
authors.initials: S
authors.lastname: Dizbay Sak
authors.forename: D
authors.initials: D
authors.lastname: Orhan
authors.forename: S
authors.initials: S
authors.lastname: Kavukçu
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D001980:Bronchi / Q000473:pathology* / Q000601:surgery; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011013:Pneumonectomy; D012189:Retrospective Studies