title: Using frozen section to identify histological patterns in stage I lung adenocarcinoma of ≤ 3 cm: accuracy and interobserver agreement.
abstract: OBJECTIVE
  The IASLC/ATS/ERS classification of lung adenocarcinoma provides a prognostically significant histological subclassification. The aim of this study was to investigate the accuracy, limitations and interobserver agreement of frozen sections for predicting histological subtype.
  
  
  RESULTS
  Frozen section and permanent section slides from 361 resected stage I lung adenocarcinomas ≤ 3 cm in size were reviewed for predominant histological subtype and the presence or absence of lepidic, acinar, papillary, micropapillary and solid patterns. Fifty cases were additionally reviewed by three pathologists to determine interobserver agreement. To test the accuracy of frozen section in judging degree of invasion, five pathologists reviewed frozen section slides from 35 cases with a predominantly lepidic pattern. There was moderate agreement on predominant histological subtype between frozen sections and final diagnosis (κ = 0.565). Frozen sections had high specificity for micropapillary and solid patterns (94% and 96%, respectively), but sensitivity was low (37% and 69%, respectively). The interobserver agreement was satisfactory (κ > 0.6, except for the acinar pattern).
  
  
  CONCLUSIONS
  Frozen section can provide information on the presence of aggressive histological patterns-micropapillary and solid-with high specificity but low sensitivity. It was difficult to predict the predominant pattern on the basis of frozen sections, mostly because of sampling issues.
authors.affiliation: Division of Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.|Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Yeh
authors.affiliation: Division of Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.|Department of Thoracic Surgery, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Nitadori
authors.affiliation: Division of Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Kyuichi
authors.initials: K
authors.lastname: Kadota
authors.affiliation: Division of Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Yoshizawa
authors.affiliation: Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Natasha
authors.initials: N
authors.lastname: Rekhtman
authors.affiliation: Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Andre L
authors.initials: AL
authors.lastname: Moreira
authors.affiliation: Department of Epidemiology & Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Camelia S
authors.initials: CS
authors.lastname: Sima
authors.affiliation: Division of Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Valerie W
authors.initials: VW
authors.lastname: Rusch
authors.affiliation: Division of Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.|Center for Cell Engineering, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Prasad S
authors.initials: PS
authors.lastname: Adusumilli
authors.affiliation: Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: William D
authors.initials: WD
authors.lastname: Travis
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005629:Frozen Sections; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D015588:Observer Variation; D011379:Prognosis; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: frozen sections; histological subtype; invasion; limited resection; lung adenocarcinoma; micropapillary; solid