<p>Clinicopathological, Immunohistochemical and Molecular Genetic Study on Epithelioid Glioblastoma: A Series of Fifteen Cases with Literature Review</p>

Abstract

Purpose: To observe the clinicopathological, immunohistochemical, and molecular genetic features of epithelioid glioblastoma (E-GBM), and identify tumor-associated prognostic factors. Patients and Methods: The clinical and radiological data of fifteen cases of E-GBM were collected, and their pathological, immunohistochemical, and molecular features were examined. A 1p/19q analysis via FISH, MGMT promoter methylation by MS-PCR, and IDH1 and BRAF V600E mutation analysis by HRM-PCR were performed. The level of EZH2 expression was valuated by immunohistochemistry in 15 E-GBM cases, and the prognostic factors were analyzed in E-GBM patients. Fifteen non-E-GBM cases were used as a control. Results: The fifteen cases of E-GBM included twelve males and three females, with fourteen cases supratentorially located. Headache was the main symptom. Microscopy revealed that the tumors were composed of epithelioid cells and some rhabdoid cells. The epithelioid and rhabdoid cells displayed focal discohesion, scant intervening neuropil, a distinct cell membrane, eosinophilic cytoplasm, and a laterally positioned nucleus. Most tumors showed high mitosis, zonal necrosis, and microvascular hyperplasia. Immunohistochemical findings included epithelioid cells positive for GFAP, vimentin, nestin, S-100, and INI-1. The molecular findings included no deletions of 1p/19q, EGFR amplifications, or IDH1 mutations in any case, a methylated MGMT promoter in 46.7% (7/15) cases, and a BRAFV600E mutation in 46.7% (7/15) cases. EZH2 overexpression occurred in 60.0% (9/15) of E-GBM cases. E-GBM patients with OS (≤12 months) exhibited extensive necrosis (6/6), EZH2 overexpression (6/6), MGMT promoter unmethylation (5/6), BRAFV600E mutation (3/6), and treatment (surgery4/6). E-GBM patients with OS (>12 months) exhibited focal or limited necrosis, low or negative EZH2 expression, MGMT promoter methylation (2/3), BRAFV600E mutation (3/3), and treatment (surgery+radiotherapy/chemo-radiotherapy, 2/3). Conclusion: E-GBM was a rare variant of glioblastoma, with histological epithelioid features and poor prognosis. Extensive necrosis, MGMT promoter unmethylation, EZH2 overexpression, and lack of adjuvant chemo-radiotherapy may indicate a poor prognosis.

Adult epithelioid glioblastoma exhibits an extremely poor prognosis and high frequency of SWI/SNF complex mutation: Insights from a retrospective study

“…5 Necrosis and microvascular proliferation have been established as the typical features of conventional glioblastoma. 7 In eGBM, zonal necrosis was more common than palisading necrosis, consistent with the previous reports, 16,17 and microvascular proliferation was less common than in typical GBM. Perivascular lymphocyte proliferation was an important morphological feature in PXA, CNS lymphoma and demyelination disease and was also observed in nearly 1/3 of cases of the eGBM.…”

Altered Elemental Distribution in Male Rat Brain Tissue as a Predictor of Glioblastoma Multiforme Growth—Studies Using SR-XRF Microscopy

“…In the case of high-grade gliomas and glioblastomas, calcifications were rarely seen [ 14 ]. However, cases of glioblastomas with the presence of calcified regions were also reported [ 34 , 35 , 36 , 37 , 38 ]. In the literature, one can find reports on clinical cases, where imaging examinations performed few years before brain tumor diagnosis revealed calcifications in the area of cancer development [ 39 , 40 ].…”

18F-Labeled WBC PET/CT Scan in a Case of Recurrent Glioblastoma Multiforme, Presented as Pyrexia of Unknown Origin

“…5 Tumor necrosis is fundamental feature of glioblastoma, and multiple necrobiotic debris can be seen in necrotic areas as visualized in our case. 6,7 However, the novel finding in our case was presence of abundant abscess areas located within and at the periphery of the tumor. WBC scan provides an in vivo demonstration of the presence of neutrophilic infiltration in surrounding tumoral tissue.…”

“…The WBC scan essentially reveals active diapedesis of granulocytes through chemotactic processes 5 . Tumor necrosis is fundamental feature of glioblastoma, and multiple necrobiotic debris can be seen in necrotic areas as visualized in our case 6,7 . However, the novel finding in our case was presence of abundant abscess areas located within and at the periphery of the tumor.…”