Brain 17 Vienna

07.11.2017

Glioblastoma

Diffuse midline glioma

• New pattern: Glioblastoma with primitive neuronal component

• K27M mutations in histone H3 gene H3F3A defines a group

Mutation-specific antibody

MYCN amp

Louiset al, Acta Neuropath 2016

Louiset al, Acta Neuropath 2016

Pattern =Histological features without clear clinical significance

New diagnostic entity

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Embryonal tumors

How many medulloblastoma groups are (currently) defined based on genetics?

Greatest conceptual challenge

• A1. 3

• A2. 4

A2 is correct

• A3. 5

Dismissal of “PNET, primitive neuroectodermal tumor“ -> “Embryonal tumor“

• A4. 9

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Medulloblastoma

Medulloblastoma

Four genetically defined groups

Long established histological groups

Surrogate IHC markers for pathway activation

+ TP53 sequencing + MYC amplification by FISH

Genetics & histology & clinical factors stratify patients into risk groups

Louis DN et al, Acta Neuropathol 2016

Northcott et al, Nature Reviews 2012

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6