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Washington University Experience | NEOPLASMS (GLIAL) | High-Grade Astrocytoma with Piloid features (HGAP) | 1I HGAP (Case 1) PAS 20X 4
PAS stains the proliferating microvasculature but does not highlight any Rosenthal fibers or EGBs. (PAS) ---- Not shown: BRAF is negative. The tumor is negative for H3K27M and the mutant form of IDH1 (R132H). H3K27me3 is retained in the tumor cells. Fluorescence in situ hybridization studies showed presence of gain of BRAF but no definite evidence to suggest presence of a KIAA1549-BRAF fusion or any other BRAF gene rearrangement. Additional send out FISH for BRAF (to Cincinnati Children’s Hospital) shows BRAF gain with no evidence of balanced rearrangement or tandem duplication of BRAF. ----
Foundation One molecular analysis reports CDKN2A/B loss and an ATRX splice site mutation. Methylation based tumor profiling provided an integrated diagnosis of High Grade Astrocytoma with Piloid features (HGAP).
