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Washington University Experience | NEOPLASMS (GLIAL) | Glioblastoma, small cell type | 12E GBM, small-cell type (Case 12) p53

Scattered p53 positive cells are present. An antibody against the R132H mutant form of IDH1 is negative. ---- Ancillary studies: The morphological and immunohistochemical features of this tumor are most consistent with a glioblastoma (WHO Grade IV). The relatively monomorphic appearance of the neoplastic cells suggests the presence of 'small cell features' in the tumor, a finding which is often associated with EGFR amplification. Indeed, FISH showed EGFR amplification but no evidence of 1p/19q co-deletion. ---- FISH showed evidence of polysomy 7 (chromosomal gain) and normal dosages (2 copies) of chromosome 1 and 19. ---- Methylation of the MGMT (O(6)-methylguanine-DNA methyltransferase) gene was detected using methylation specific PCR technologies.

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