title: Gleason grade 4 prostate adenocarcinoma patterns: an interobserver agreement study among genitourinary pathologists.
abstract: OBJECTIVE
  To assess the interobserver reproducibility of individual Gleason grade 4 growth patterns.
  
  
  RESULTS
  Twenty-three genitourinary pathologists participated in the evaluation of 60 selected high-magnification photographs. The selection included 10 cases of Gleason grade 3, 40 of Gleason grade 4 (10 per growth pattern), and 10 of Gleason grade 5. Participants were asked to select a single predominant Gleason grade per case (3, 4, or 5), and to indicate the predominant Gleason grade 4 growth pattern, if present. 'Consensus' was defined as at least 80% agreement, and 'favoured' as 60-80% agreement. Consensus on Gleason grading was reached in 47 of 60 (78%) cases, 35 of which were assigned to grade 4. In the 13 non-consensus cases, ill-formed (6/13, 46%) and fused (7/13, 54%) patterns were involved in the disagreement. Among the 20 cases where at least one pathologist assigned the ill-formed growth pattern, none (0%, 0/20) reached consensus. Consensus for fused, cribriform and glomeruloid glands was reached in 2%, 23% and 38% of cases, respectively. In nine of 35 (26%) consensus Gleason grade 4 cases, participants disagreed on the growth pattern. Six of these were characterized by large epithelial proliferations with delicate intervening fibrovascular cores, which were alternatively given the designation fused or cribriform growth pattern ('complex fused').
  
  
  CONCLUSIONS
  Consensus on Gleason grade 4 growth pattern was predominantly reached on cribriform and glomeruloid patterns, but rarely on ill-formed and fused glands. The complex fused glands seem to constitute a borderline pattern of unknown prognostic significance on which a consensus could not be reached.
authors.affiliation: Department of Pathology, Erasmus Medical Centre, Rotterdam, The Netherlands.
authors.forename: Charlotte F
authors.initials: CF
authors.lastname: Kweldam
authors.affiliation: Department of Public Health, Erasmus Medical Centre, Rotterdam, The Netherlands.
authors.forename: Daan
authors.initials: D
authors.lastname: Nieboer
authors.affiliation: Department of Pathology, Universitat Autónoma de Barcelona, Barcelona, Spain.
authors.forename: Ferran
authors.initials: F
authors.lastname: Algaba
authors.affiliation: Department of Pathology & Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Mahul B
authors.initials: MB
authors.lastname: Amin
authors.affiliation: Department of Cellular Pathology, The Royal London Hospital, London, UK.
authors.forename: Dan M
authors.initials: DM
authors.lastname: Berney
authors.affiliation: Department of Anatomical Pathology, School of Medical Sciences, State University of Campinas (Unicamp), Campinas, Brazil.
authors.forename: Athanase
authors.initials: A
authors.lastname: Billis
authors.affiliation: Bostwick Laboratories, Orlando, FL, USA.
authors.forename: David G
authors.initials: DG
authors.lastname: Bostwick
authors.affiliation: Institute for Pathology, University Hospital Basel, Basel, Switzerland.
authors.forename: Lukas
authors.initials: L
authors.lastname: Bubendorf
authors.affiliation: Department of Pathology & Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Service d'Anatomie & Cytologie Pathologiques du Pr Capron, Hôpital de la Pitié-Salpêtrière, Paris, France.
authors.forename: Eva
authors.initials: E
authors.lastname: Compérat
authors.affiliation: Department of Pathology and Molecular Medicine, Wellington School of Medicine and Health Sciences, University of Otago, Wellington, New Zealand.
authors.forename: Brett
authors.initials: B
authors.lastname: Delahunt
authors.affiliation: Department of Oncology and Pathology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Egevad
authors.affiliation: Department of Pathology & Laboratory Medicine, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Evans
authors.affiliation: Department of Pathology, University of California San Diego, La Jolla, CA, USA.
authors.forename: Donna E
authors.initials: DE
authors.lastname: Hansel
authors.affiliation: Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Humphrey
authors.affiliation: Institute of Pathology, University of Bonn, Bonn, Germany.
authors.forename: Glen
authors.initials: G
authors.lastname: Kristiansen
authors.affiliation: Department of Pathology & Laboratory Medicine, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Theodorus H
authors.initials: TH
authors.lastname: van der Kwast
authors.affiliation: Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Cristina
authors.initials: C
authors.lastname: Magi-Galluzzi
authors.affiliation: Section of Pathological Anatomy, Department of Biomedical Sciences and Public Health, Polytechnic University of the Marche Region (Ancona), Ancona, Italy.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Montironi
authors.affiliation: Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: George J
authors.initials: GJ
authors.lastname: Netto
authors.affiliation: Aquesta Pathology and University of Queensland, Brisbane, Qld, Australia.
authors.forename: Hemamali
authors.initials: H
authors.lastname: Samaratunga
authors.affiliation: Trillium Health Partners, Mississauga and McMaster University, Hamilton, ON, Canada.
authors.forename: John R
authors.initials: JR
authors.lastname: Srigley
authors.affiliation: Department of Pathology, Singapore General Hospital, Singapore.
authors.forename: Puay H
authors.initials: PH
authors.lastname: Tan
authors.affiliation: Department of Medical Genetics, Haematology and Pathology, Cardiff University, Cardiff, UK.
authors.forename: Murali
authors.initials: M
authors.lastname: Varma
authors.affiliation: Department of Pathology, NYU Langone Medical Center, New York, NY, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Department of Pathology, Erasmus Medical Centre, Rotterdam, The Netherlands.
authors.forename: Geert J L H
authors.initials: GJ
authors.lastname: van Leenders
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D006801:Humans; D008297:Male; D060787:Neoplasm Grading; D015588:Observer Variation; D000072142:Pathologists; D010338:Pathology, Clinical; D011471:Prostatic Neoplasms / Q000473:pathology*
keywords: Gleason grading; interobserver variability; prostate cancer