Frequent Diagnostic Under-Grading in Isocitrate Dehydrogenase Wild-Type Gliomas due to Small Pathological Tissue Samples.
Glioma
Histology
IDH
Molecular pathology
Pathology
Sampling error
WHO grade
Journal
Neurosurgery
ISSN: 1524-4040
Titre abrégé: Neurosurgery
Pays: United States
ID NLM: 7802914
Informations de publication
Date de publication:
01 11 2019
01 11 2019
Historique:
received:
03
11
2017
accepted:
16
08
2018
pubmed:
20
10
2018
medline:
26
3
2020
entrez:
19
10
2018
Statut:
ppublish
Résumé
In contrast to isocitrate dehydrogenase (IDH) mutation analysis, which is homogenous within a given tumor, diagnostic errors in histological analysis following the 2016 World Health Organization (WHO) classification could be due to small samples because of histological heterogeneity. To assess whether the sample size sent to histopathology influences the tumor grading in IDH wild-type gliomas. Histologically diagnosed WHO grade, sample volume, and preoperative tumor volume data of 111 patients aged who received resection of IDHwt gliomas between January 2007 and December 2015 at our hospital were evaluated. The differences between absolute and relative pathological sample sizes stratified by WHO grade were conducted using One-Way-Permutation-Test. With a mean sample size of 10.9 cc, 83.8% of patients were histologically diagnosed as WHO grade IV, while 16.2% of patients with a mean sample size of 2.62 cc were diagnosed as WHO grade II/III. One-Way-Permutation-Test showed a significant difference between absolute tissue samples stratified by WHO grade (P = .0374). The distribution of preoperative tumor volumes with WHO grade IV vs WHO grade II/III showed no significant difference (P = .8587). Of all tumors with a sample size >10 cc 100% were pathologically diagnosed as WHO grade IV and those with sample size >5 cc 93.5% were diagnosed as WHO grade IV. Small sample sizes are associated with a higher risk of under-estimating malignancy in histological grading in IDHwt gliomas. This study suggests a standard minimum sample size (>5cc) in every resection. Modalities of adjuvant treatment for IDHwt, WHO grade II/III gliomas need to reflect a prognosis that is only marginally better than of a glioblastoma.
Sections du résumé
BACKGROUND
In contrast to isocitrate dehydrogenase (IDH) mutation analysis, which is homogenous within a given tumor, diagnostic errors in histological analysis following the 2016 World Health Organization (WHO) classification could be due to small samples because of histological heterogeneity.
OBJECTIVE
To assess whether the sample size sent to histopathology influences the tumor grading in IDH wild-type gliomas.
METHODS
Histologically diagnosed WHO grade, sample volume, and preoperative tumor volume data of 111 patients aged who received resection of IDHwt gliomas between January 2007 and December 2015 at our hospital were evaluated. The differences between absolute and relative pathological sample sizes stratified by WHO grade were conducted using One-Way-Permutation-Test.
RESULTS
With a mean sample size of 10.9 cc, 83.8% of patients were histologically diagnosed as WHO grade IV, while 16.2% of patients with a mean sample size of 2.62 cc were diagnosed as WHO grade II/III. One-Way-Permutation-Test showed a significant difference between absolute tissue samples stratified by WHO grade (P = .0374). The distribution of preoperative tumor volumes with WHO grade IV vs WHO grade II/III showed no significant difference (P = .8587). Of all tumors with a sample size >10 cc 100% were pathologically diagnosed as WHO grade IV and those with sample size >5 cc 93.5% were diagnosed as WHO grade IV.
CONCLUSION
Small sample sizes are associated with a higher risk of under-estimating malignancy in histological grading in IDHwt gliomas. This study suggests a standard minimum sample size (>5cc) in every resection. Modalities of adjuvant treatment for IDHwt, WHO grade II/III gliomas need to reflect a prognosis that is only marginally better than of a glioblastoma.
Identifiants
pubmed: 30335178
pii: 5134283
doi: 10.1093/neuros/nyy433
doi:
Substances chimiques
Isocitrate Dehydrogenase
EC 1.1.1.41
Types de publication
Journal Article
Observational Study
Langues
eng
Sous-ensembles de citation
IM
Pagination
689-694Informations de copyright
Copyright © 2018 by the Congress of Neurological Surgeons.