Immunohistochemical and molecular genetic study on epithelioid glioblastoma: Series of seven cases with review of literature

Pathol Res Pract. 2018 May;214(5):679-685. doi: 10.1016/j.prp.2018.03.019. Epub 2018 Mar 22.


Epithelioid glioblastoma (e-gbm) is a recently described variant of glioblastoma (GBM) which is associated with short survival and now added as a provisional entity to WHO 2016 classification of CNStumors. About half of these tumors show characteristic BRAF-V600E mutation. However, unlike conventional GBMs, e-gbm lack specific diagnostic and prognostic markers. Hence, we aimed to molecularly characterize these tumors. An extensive review of literature was performed.In a multi-institutional effort, all the cases of glioblastoma of year 2017 were reviewed. Cases with predominant epithelioid morphology were analysed. Seven cases of e-gbm (adults:4 and pediatric: 3) were identified. Duration of symptoms varied from 2 weeks to one month. Radiologically, all cases were supratentorial, contrast enhancing with solid and cystic appearance. Majority of the cases were immunopositive for GFAP (71%), EMA (71%), S100 (71%) and vimentin (85%). All the cases showed ATRX, INI-1 and H3K27me3 expression. BRAFV600Emutation was seen in 28% of cases. TERT mutation was seen in 40% cases, while one case showed EGFR amplification. H3F3A mutations and PTEN deletions were seen in none. Although e-gbms are rare, epithelioid morphology of a CNS tumor in a young adult or children with areas of necrosis needs thorough histomorphological and genetic workup.

Keywords: BRAFV600E; EGFR amplification; Epithelioid glioblastoma; TERT.

Publication types

  • Review

MeSH terms

  • Astrocytoma / genetics
  • Astrocytoma / metabolism
  • Astrocytoma / pathology
  • Brain Neoplasms / genetics*
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology*
  • Glioblastoma / genetics*
  • Glioblastoma / metabolism
  • Glioblastoma / pathology*
  • Humans
  • Mutation / genetics
  • PTEN Phosphohydrolase / genetics
  • Proto-Oncogene Proteins B-raf / genetics


  • Proto-Oncogene Proteins B-raf
  • PTEN Phosphohydrolase
  • PTEN protein, human