title: Interobserver Agreement on Pathologic Features of Liver Biopsy Tissue in Patients with Nonalcoholic Fatty Liver Disease.
abstract: BACKGROUND
  The histomorphologic criteria for the pathological features of liver tissue from patients with non-alcoholic fatty liver disease (NAFLD) remain subjective, causing confusion among pathologists and clinicians. In this report, we studied interobserver agreement of NAFLD pathologic features and analyzed causes of disagreement.
  
  
  METHODS
  Thirty-one cases of clinicopathologically diagnosed NAFLD from 10 hospitals were selected. One hematoxylin and eosin and one Masson's trichrome-stained virtual slide from each case were blindly reviewed with regard to 12 histological parameters by 13 pathologists in a gastrointestinal study group of the Korean Society of Pathologists. After the first review, we analyzed the causes of disagreement and defined detailed morphological criteria. The glass slides from each case were reviewed a second time after a consensus meeting. The degree of interobserver agreement was determined by multi-rater kappa statistics.
  
  
  RESULTS
  Kappa values of the first review ranged from 0.0091-0.7618. Acidophilic bodies (k = 0.7618) and portal inflammation (k = 0.5914) showed high levels of agreement, whereas microgranuloma (k = 0.0984) and microvesicular fatty change (k = 0.0091) showed low levels of agreement. After the second review, the kappa values of the four major pathological features increased from 0.3830 to 0.5638 for steatosis grade, from 0.1398 to 0.2815 for lobular inflammation, from 0.1923 to 0.3362 for ballooning degeneration, and from 0.3303 to 0.4664 for fibrosis.
  
  
  CONCLUSIONS
  More detailed histomorphological criteria must be defined for correct diagnosis and high interobserver agreement of NAFLD.
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Eun Sun
authors.initials: ES
authors.lastname: Jung
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyoungbun
authors.initials: K
authors.lastname: Lee
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Eunsil
authors.initials: E
authors.lastname: Yu
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Inje University Seoul Paik Hospital, Seoul, Korea.
authors.forename: Yun Kyung
authors.initials: YK
authors.lastname: Kang
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Mee-Yon
authors.initials: MY
authors.lastname: Cho
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Inha University Hospital, Incheon, Korea.
authors.forename: Joon Mee
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Chonbuk National University Medical School, Jeonju, Korea.
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Moon
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Dong-A University College of Medicine, Busan, Korea.
authors.forename: Jin Sook
authors.initials: JS
authors.lastname: Jeong
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Cheol Keun
authors.initials: CK
authors.lastname: Park
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Daegu Catholic University College of Medicine, Daegu, Korea.
authors.forename: Jae-Bok
authors.initials: JB
authors.lastname: Park
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Dae Young
authors.initials: DY
authors.lastname: Kang
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Sohn
authors.affiliation: Gastrointestinal Pathology Study Group of Korean Society of Pathologist, Seoul, Korea.|Department of Pathology, Soon Chun Hyang University Seoul Hospital, Seoul, Korea.
authors.forename: So-Young
authors.initials: SY
authors.lastname: Jin
keywords: Interobserver agreement; Non-alcoholic fatty liver disease; Pathologic features