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Washington University Experience | NEOPLASMS (GLIAL) | Glioblastoma, small cell type | 22A3 GBM, small cell type (Case 22) H&E 1.jpg
This is a cellular neoplasm composed predominantly of monomorphic-appearing cells with eosinophilic fibrillary processes and nuclei characterized by round to ovoid, moderately irregular contours, scattered prominent nucleoli, and coarse clumped chromatin. In this region there is prominent perineuronal satelliting. ---- Ancillary studies (not shown): FISH The tumor is positive for both EGFR amplification and PTEN/10q loss, consistent with the cytogenetic profile of small cell glioblastoma.
Additionally, an immunostain for IDH1 mutant protein (pR132H) was performed and is negative.
Methylation of the MGMT (O(6)-methylguanine-DNA methyltransferase) gene was detected using methylation specific PCR technologies. ---- Targeted next-generation sequencing (NGS) was performed on this sample of small cell glioblastoma, grade IV, as part of the Genomics and Pathology Services Comprehensive Cancer Gene Set. Several non-synonymous sequence variants were identified, including a large deletion variant involving exon 25 of EGFR. ---- Overall, the histomorphologic and molecular features are those of a glioblastoma, small cell subtype.
