Standardization of canine meningioma grading: validation of new guidelines for reproducible histopathologic criteria

Sara Belluco (1, 2) , Giuseppe Marano (3) , T. Lurier (4) , Giancarlo Avallone (5) , Chiara Brachelente (6) , Stefano Di Palma (7) , Roberta Rasotto (8) , Kerstin Baiker (9) , Andreas Beineke (10) , Anna Oevermann (11) , Frauke Seehusen (12) , Fabiano José Ferreira de Sant'Ana (13) , Patrizia Boracchi (3) , Martí Pumarola (14) , Maria Teresa Mandara (6)

1 ICE - Interactions Cellules Environnement - UR
2 VAS - VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement
3 UNIMI - Università degli Studi di Milano = University of Milan
4 UMR EPIA - Unité Mixte de Recherche d'Épidémiologie des maladies Animales et zoonotiques
5 UNIBO - Alma Mater Studiorum Università di Bologna = University of Bologna
6 UNIPG - Università degli Studi di Perugia = University of Perugia
7 Idexx Laboratories
8 Diagnostic Pathology, Dick White Referrals, Station Farm, Cambridgeshire
9 CUHK - City University of Hong Kong [Hong Kong]
10 Stiftung Tierärztliche Hochschule Hannover, Institut für Pathologie
11 UNIBE - Universität Bern / University of Bern
12 UZH - Universität Zürich [Zürich] = University of Zurich
13 UnB - Universidade de Brasilia [Brasília]
14 UAB - Universitat Autònoma de Barcelona = Autonomous University of Barcelona = Universidad Autónoma de Barcelona

Abstract Canine meningiomas are currently graded using the human grading system. Recently published guidelines have adapted the human grading system for use in dogs. The goal of this study was to validate the new guidelines for canine meningiomas. To evaluate the inter‐observer agreement, 5 veterinary surgical pathologists graded 158 canine meningiomas following the human grading system alone or with the new guidelines. The inter‐observer agreement for histologic grade and each of the grading criteria (mitotic grade, invasion, spontaneous necrosis, macronucleoli, small cells, hypercellularity, pattern loss and anaplasia) was evaluated using the Fleiss kappa index. The diagnostic accuracy (sensitivity and specificity) was assessed by comparing the diagnoses obtained with the 2 grading systems with a consensus grade (considered the reference classification). The consensus histologic grade was obtained by agreement between 4 experienced veterinary neuropathologists following the guidelines. Compared with the human grading alone, the canine‐specific guidelines increased the inter‐observer agreement for: histologic grade ( κ = 0.52); invasion ( κ = 0.67); necrosis ( κ = 0.62); small cells ( κ = 0.36); pattern loss ( κ = 0.49) and anaplasia ( κ = 0.55). Mitotic grade agreement remained substantial ( κ = 0.63). The guidelines improved the sensitivity in identifying grade 1 (95.6%) and the specificity in identifying grade 2 (96.2%) meningiomas. In conclusion, the new grading guidelines for canine meningiomas are associated with an overall improvement in the inter‐observer agreement and higher diagnostic accuracy in diagnosing grade 1 and grade 2 meningiomas.

Mots clés: meningioma; standardization; central nervous system; dog; grading; classification; dogs; agreement; diagnosis

Domaines: Santé publique et épidémiologie

Sara Belluco, Giuseppe Marano, T. Lurier, Giancarlo Avallone, Chiara Brachelente, et al.. Standardization of canine meningioma grading: validation of new guidelines for reproducible histopathologic criteria. Veterinary and Comparative Oncology, 2023, 21 (4), pp.685-699. ⟨10.1111/vco.12932⟩. ⟨hal-04189400v2⟩