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Washington University Experience | NEOPLASMS (GLIAL) | Glioblastoma, small cell type | 18C2 GBM, small cell type (Case 18) EGFR block A2

There is a high level of EGFR amplification. In our lab at that time (2015) the accepted criterion for low-level EGFR amplification was an EGFR:CEP7 ratio of ≥ 2.0 but less than 20.0, and high-level amplification was defined as EGFR:CEP7 ratio ≥20.0 or innumerable. ---- The histologic findings of cytologic uniformity with very high mitotic rate support the diagnosis of small cell glioblastoma. EGFR amplification and PTEN deletion are frequently reported in this glioblastoma variant, providing additional support for this interpretation. ---- Ancillary studies: Immunohistochemistry for mutant IDH-1 (p.R132H) is negative. Methylation of the MGMT (O(6)-methylguanine-DNA methyltransferase) gene was not detected using methylation specific PCR technologies.

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