Meningioma sampling: how much is enough for the accurate grading of atypical meningiomas?

Col, Pierre Dal; Garaix, Thierry; Massard, Anna; Vassal, François; Rivoirard, Romain; Dumollard, Jean‐Marc; Barral-Clavel, Fanélie; Billen, Claire; Ramirez, Carole; Péoc’h, Michel; Forest, Fabien

doi:10.1016/j.pathol.2020.10.024

Cited by 4 publications

(6 citation statements)

References 14 publications

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“…For human meningioma, six blocks per tumour are recommended to achieve 95% accuracy in grading Grade II tumours. 34 In the present study, reduced size contributed to the decreased inter-observer agreement, since samples less than 10 mm 2 in size obtained only a fair agreement for both histologic and mitotic grade (CCC TOT for histologic grade = 0.38; for mitotic grade = 0.37). Small samples are more easily affected by artefactual changes due to handling, which impedes the assessment of some criteria (necrosis, mitotic figures).…”

Section: Sample Sizecontrasting

confidence: 49%

“…With the spreading of image techniques, in the near future biopsies are going to increase in number, and sample size will have more relevance in diagnostic routines. For human meningioma, six blocks per tumour are recommended to achieve 95% accuracy in grading Grade II tumours 34 . In the present study, reduced size contributed to the decreased inter‐observer agreement, since samples less than 10 mm 2 in size obtained only a fair agreement for both histologic and mitotic grade (CCC TOT for histologic grade = 0.38; for mitotic grade = 0.37).…”

Section: Discussionmentioning

confidence: 58%

“…Small samples are more easily affected by artefactual changes due to handling, which impedes the assessment of some criteria (necrosis, mitotic figures). Moreover, since most criteria can be expressed multifocally, it is important to evaluate as much tissue as possible 34 …”

Section: Discussionmentioning

confidence: 99%

“…Moreover, since most criteria can be expressed multifocally, it is important to evaluate as much tissue as possible. 34 Tumour subtype. In human medicine, though 15 meningioma subtypes are described, few of them present a real prognostic value.…”

Section: Sample Sizementioning

confidence: 99%

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Standardisation of canine meningioma grading: Inter‐observer agreement and recommendations for reproducible histopathologic criteria

Belluco

Marano

Baiker

et al. 2022

Vet Comparative Oncology

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The human grading system is currently applied to canine meningioma, although it has not been validated in dogs. The present study focused on standardising the human grading system applied to canine meningioma. Four veterinary neuropathologists graded 186 canine meningiomas as follows: Grade I tumour, with <4 mitoses/2.37 mm2; Grade II tumour, with ≥4 mitoses/2.37 mm2, brain invasion or at least three of the following criteria: sheeting architecture, hypercellularity, small cells, macronucleoli, necrosis; Grade III tumour, with ≥20 mitoses/2.37 mm2 or anaplasia. Slides with grading disagreement were reviewed to define a consensus diagnosis and to assess reproducible criteria. Concordance between histologic grade and the consensus diagnosis, as well as intra‐ and inter‐observer agreements for each criterion, were statistically analysed. Concordance between histologic grade and consensus diagnosis ranged from 59% to 100%, with lower concordance for Grade I and II tumours. The lowest inter‐observer agreement was recorded for macronucleoli, small cells, hypercellularity and sheeting architecture. Tumour invasion and necrosis displayed fair agreement, while moderate agreement was reached for mitotic grade and anaplasia. The following recommendations were issued to improve the reproducibility of canine meningioma grading: (1) Assess mitotic grade in consecutive HPFs within the most mitotically active area; (2) Define invasion as neoplastic protrusions within central nervous tissue without pial lining; (3) Report spontaneous necrosis; (4) Report prominent nucleoli when visible at ×100; (5) Report pattern loss when visible at ×100 in >50% of the tumour; (6) Report necrosis, small cells, hypercellularity and macronucleoli, even when focal; (7) Report anaplasia if multifocal.

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Section: Sample Sizecontrasting

confidence: 49%

Section: Discussionmentioning

confidence: 58%

Section: Discussionmentioning

confidence: 99%

Section: Sample Sizementioning

confidence: 99%

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Standardisation of canine meningioma grading: Inter‐observer agreement and recommendations for reproducible histopathologic criteria

Belluco

Marano

Baiker

et al. 2022

Vet Comparative Oncology

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“…However, using the guidelines, the grade 1 specificity and grade 2 sensitivity were slightly decreased, remaining between 40% and 60%, supporting the idea that many grade 2 meningiomas can be misdiagnosed as grade 1 tumours. This is a well-known problem for three-tier grading systems, 46 supporting the proposal of two-tier grading systems for some animal tumours. 32,47 In conclusion, the guidelines allowed an overall increased agreement among surgical pathologists as well as better detection of grade 1 and grade 3 tumours, thus they should be integrated into the current grading system for canine meningioma.…”

Section: Diagnostic Accuracysupporting

confidence: 67%

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

Belluco,

Marano,

Lurier

et al. 2023

Vet Comparative Oncology

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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.

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Differential Expression of Proteins and Genes at the Tumor‐Brain Interface in Invasive Meningioma

Senglek,

Teerapakpinyo,

Jittapiromsak

et al. 2024

Genes Chromosomes & Cancer

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Most meningiomas are dural‐based extra‐axial tumors in close contact with the brain. Expression of genes and proteins at the tumor‐brain interface in brain‐invasive meningioma is basically unknown. Using the NanoString pan‐cancer panel, differential expression of genes in the invasive edge versus main tumor body was determined in 12 invasive meningiomas (comprising the discovery cohort), and 6 candidate genes: DTX1, RASGRF1, GRIN1, TNR, IL6, and NR4A1, were identified. By immunohistochemistry, DTX1 and RASGRF1 expression correlated with gene expression, and were studied in an expanded cohort of 21 invasive and 15 noninvasive meningiomas, together with Ki‐67. Significantly higher expression of DTX1, RASGFR1, and Ki‐67 was found in the invasive edge compared with the main tumor body. Increased expression of RASGRF1 and Ki‐67 was more clearly associated with brain invasion. The situation with DTX1 was less definitive since increased expression was observed in meningiomas both at the invasive edge and when in close contact with brain but without invasion. Pathway analyses identified significant links between DTX1 and RASGRF1 and key biological processes, including cell–cell adhesion, and signaling pathways including Notch, RAS, MAPK, and Rho. Higher expression of DTX1, RASGRF1, and Ki‐67 in the brain‐invasive area of meningiomas suggests that these proteins play a role in the process of brain invasion.

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Meningioma sampling: how much is enough for the accurate grading of atypical meningiomas?

Cited by 4 publications

References 14 publications

Standardisation of canine meningioma grading: Inter‐observer agreement and recommendations for reproducible histopathologic criteria

Standardisation of canine meningioma grading: Inter‐observer agreement and recommendations for reproducible histopathologic criteria

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

Differential Expression of Proteins and Genes at the Tumor‐Brain Interface in Invasive Meningioma

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