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Embryonal Tumors

Institute of Neuropathology

Brain Tumor Reference Center

Torsten Pietsch

European Congress of Pathology, Amsterdam, September 5, 2017

Revision of the WHO classification

2007 2016

The “M&M“ future of brain tumor classification:

A smart synthesis of Morphological and Molecular informationThe future of (neuro)pathology

Smart synthesis of morphological and molecular information!

TCGA Research Network et al.

Nature Genetics 2013;45:1113

WHO‘s next ?Integration of histological and molecular information

WHO‘s next ?Integration of histological and molecular information

Louis et al., Brain Pathol, 2014

Layer 1: Integrated diagnosis (incorporating all

tissue-based information)

Layer 2: Histopathological diagnosis

Layer 3: Histopathological grade (WHO grade)

Layer 4: Molecular Information

Proposed multilayered diagnosis format:

WHO 2007 Embryonal Tumor Classification

Medulloblastoma

Medulloblastoma (classic) 9470

Desmoplastic/Nodular MB 9471

MB with extensive nodularity 9471

Anaplastic MB 9474

Large cell MB 9474

CNS-PNET

CNS PNET NOS 9473

CNS Neuroblastoma 9500

CNS Ganglioneuroblastoma 9490

Ependymoblastoma 9392

Medulloepithelioma 9501

AT/RT 9508

Embryonal Tumors

Medulloblastoma, genetically definedMedulloblastoma, WNT-activatedMedulloblastoma, SHH-activated, TP53 mutated Medulloblastoma, SHH-activated, TP53 wild-type Medulloblastoma, non-WNT/non-SHH

Medulloblastoma, Group 3 Medulloblastoma, Group 4

Medulloblastoma, histologically definedMedulloblastoma, classicMedulloblastoma, desmoplastic/nodularMedulloblastoma with extensive nodularityMedulloblastoma, large cell/anaplastic

Medulloblastoma, NOS

Embryonal tumour with multilayered rosettes, C19MC AlteredEmbryonal tumour with multilayered rosettes, NOSMedulloepitheliomaCNS NeuroblastomaCNS GanglioneuroblastomaCNS Embryonal tumour, NOS

Atypical teratoid/rhabdoid tumourCNS Embryonal tumour with rhabdoid features

WHO classification 2016

Embryonal Tumors

Medulloblastoma, genetically definedMedulloblastoma, WNT-activatedMedulloblastoma, SHH-activated, TP53 mutated Medulloblastoma, SHH-activated, TP53 wild-type Medulloblastoma, non-WNT/non-SHH

Medulloblastoma, Group 3 Medulloblastoma, Group 4

Medulloblastoma, histologically definedMedulloblastoma, classicMedulloblastoma, desmoplastic/nodularMedulloblastoma with extensive nodularityMedulloblastoma, large cell/anaplastic

Medulloblastoma, NOS

Embryonal tumour with multilayered rosettes, C19MC AlteredEmbryonal tumour with multilayered rosettes, NOSMedulloepitheliomaCNS NeuroblastomaCNS GanglioneuroblastomaCNS Embryonal tumour, NOS

Atypical teratoid/rhabdoid tumourCNS Embryonal tumour with rhabdoid features

WHO classification 2016

Deletion of the SMARCB1 locus on chromosome 22

SmarcB1

- Immunohistochemistry: loss of SMARCB1 gene product

Diagnosis: Atypical Teratoid-/Rhabdoid Tumor (WHO grade IV)

New AT/RT Classification (WHO 2016)

• Diagnosis of atypical teratoid/rhabdoid tumourrequires demonstration of inactivation of SMARCB1/INI1 or, if intact, SMARCA4/BRG1 genes by either routine immunohistochemical staining for the proteins or other appropriate means.

• Tumours lacking this molecular genetic confirmation should be designated as embryonal CNS tumours with rhabdoid features

Vimentin EMA

Cytokeratin Ini-1

Embryonal Tumors

Medulloblastoma, genetically definedMedulloblastoma, WNT-activatedMedulloblastoma, SHH-activated, TP53 mutated Medulloblastoma, SHH-activated, TP53 wild-type Medulloblastoma, non-WNT/non-SHH

Medulloblastoma, Group 3 Medulloblastoma, Group 4

Medulloblastoma, histologically definedMedulloblastoma, classicMedulloblastoma, desmoplastic/nodularMedulloblastoma with extensive nodularityMedulloblastoma, large cell/anaplastic

Medulloblastoma, NOS

Embryonal tumour with multilayered rosettes, C19MC AlteredEmbryonal tumour with multilayered rosettes, NOSMedulloepitheliomaCNS NeuroblastomaCNS GanglioneuroblastomaCNS Embryonal tumour, NOS

Atypical teratoid/rhabdoid tumourCNS Embryonal tumour with rhabdoid features

WHO classification 2016

ETMR

EpendymoblastomaWHO 2007

Definition:

A rare malignant, embryonal tumour manifesting in neonates and young children, histologically characterized by

distinctive multilayered rosettes

Eberhart et al., Pediatr. Dev. Pathol., 2000Gessi et al., Am. J. Surg Pathol., 2009

Embryonal tumor with abundant neuropil and true rosettes (ETANTR)

> a novel entity ??

ETANTR

Ependymoblastoma

Medulloepithelioma

Ependymoblastoma (WHO 2007)ETANTR (Embryonal Tumor with abundant neuropil and true rosettes)

ETANER (......ependymoblastic rosettes)ETMR (... multilayered rosettes)

Group 1 CNS-PNET…

Ependymoblastoma (WHO 2007)ETANTR (Embryonal Tumor with abundant neuropil and true rosettes)

ETANER (......ependymoblastic rosettes)ETMR (... multilayered rosettes)

Group 1 CNS-PNET…

Voting of theexperts:

ETMR (Embryonal Tumor with multilayered rosettes), C19MC altered

Amplification of a microRNA cluster on chromosome 19q13.42

FISH

MIP

Amplification of a microRNA cluster on chromosome 19q13.42

LIN28

WHO 2007 > WHO 2016

CNS-PNET

CNS PNET NOS 9473 CNS Embryonal tumour, NOS

CNS Neuroblastoma 9500 CNS Neuroblastoma

CNS Ganglioneuroblastoma 9490 CNS Ganglioneuroblastoma

Ependymoblastoma 9392 ETMR, C19MC Altered

ETMR, NOS

Medulloepithelioma 9501 Medulloepithelioma *

*w/o CH19MC alteration

CNS (Ganglio)neuroblastoma

Sturm et al. Cell 2016

WHO 2007 > WHO 2016

CNS-PNET CNS Embryonal tumor

CNS PNET NOS 9473 CNS Embryonal tumour, NOS

CNS Neuroblastoma 9500 CNS Neuroblastoma

CNS Ganglioneuroblastoma 9490 CNS Ganglioneuroblastoma

Ependymoblastoma 9392 ETMR, C19MC Altered

ETMR, NOS

Medulloepithelioma 9501 Medulloepithelioma *

*w/o CH19MC alteration

Most frequent malignant brain tumor

of childhood

age: 0-40 J, peak at 7 years

Localization: Cerebellum

Anamnesis: short

Symptoms: Brain pressure, cerebellar symptoms

approx. 25% c.s.f. seeding at diagnosis

Therapy: OP, chemotherapy, irradiation

Prognosis: 50-60 % long-term survivors

Medulloblastoma

WHO 2007 Embryonal Tumor Classification

Medulloblastoma

Medulloblastoma (classic) 9470

Desmoplastic/Nodular MB 9471

MB with extensive nodularity 9471

Anaplastic MB 9474

Large cell MB 9474

CNS-PNET

CNS PNET NOS 9473

CNS Neuroblastoma 9500

CNS Ganglioneuroblastoma 9490

Ependymoblastoma 9392

Medulloepithelioma 9501

AT/RT 9508

Large cell medulloblastoma Anaplastic medulloblastoma

- Mixed forms with both components occur.- Both variants are related to worse prognosis.

> WHO 2016: simplified category: Large cell/anaplastic MB

Progenitor cells

classic MB MB with extensive nodularity

Desmoplastic/nodular MB

WNT activation

Mutation CTNNB1

Monosomy 6

Hedgehog activation

Mutation PTCH1, SUFU, SMO

LOH 9q, LOH 10q

Loss 17p

Gain 17q

others

myc amplification

others

EGLventricular

matrix

large cell MB / anaplastic MB

cpa /midline

tumorshemispheric or

midline tumors

lower rhombic lip

MycN-GLI2 amplif.

loss TP53

classic MB

“Medulloblastoma“ represents five different diseases

midline

tumors

Medulloblastoma, histologically defined

Medulloblastoma, classicMedulloblastoma, desmoplastic/nodularMedulloblastoma with extensive nodularityMedulloblastoma, large cell/anaplastic

Medulloblastoma, genetically defined

Medulloblastoma, WNT-activatedMedulloblastoma, SHH-activated, TP53 mutated Medulloblastoma, SHH-activated, TP53 wild-type Medulloblastoma, non-WNT/non-SHH

Medulloblastoma, Group 3*Medulloblastoma, Group 4*

Medulloblastoma, NOS

* provisional variants

WHO Classification 2016

ß-catenin in the wnt signaling pathway

20-1571 (mutated) 60-221 (wt control)

-catenin nuclear accumulation

PNET 3 trial:

27 out of 109 non-nodular/desmopl. MBs (25%)show nuclear ß-catenin staining

5y OS 92.3 % vs. 65.3 % (p= .0015)

Standard Risk:Standard Therapy

Low Risk:Reduced Therapy

High Risk: Maximal /

novel Therapies

SURGERY

Histology

+

MolecularPhenotype

+

ClinicalFactors

PNET5 Medulloblastoma Stratification

3 weeks

WNT medulloblastomas frequently show monosomy 6

Integrated diagnosis

Integrated Diagnosis

Histological Classification Classic medulloblastoma

WHO Grade IV

Molecular Information pending

Integrated diagnosis

Integrated Diagnosis Classic medulloblastoma, WNT activated, WHO grade IV

Histological Classification

Classic medulloblastoma

WHO Grade IV

Molecular Information CTNNB1 exon 3 mutated, monosomy 6

Pietsch et al., Acta NP 2014

Smoh

MycN

PTCH

GLI1

Ptch

Hh

Costal-2

Su(Fu) Fused

Gli

Activation of Shh Signalling by Mutations in Medulloblastomas

Progression-free Survival among 23 Children with Classic and 20 Children with Desmoplastic Medulloblastoma.

Rutkowski S et al. N Engl J Med 2005;352:978-986.

Kinases

TrkA TrkB TrkC

NGF BDNF NT3

p75NTR

Death domain

NTs

Neuronal death (Apoptosis) Neuronal survival

p75-NTR is a SHH target and expressed in cerebellar progenitor cells and desmoplastic type medulloblastomas

Bühren et al., JNEN 2000, Küchler et al., IJC 2011

Immunohistochemistry for absence and presence of Shh and Wnt activation

• anti- ß-catenin (nuclei positive in Wnt MBs)• anti- YAP1 (nuclei positive in Wnt and Shh MBs)• anti- p75 NGFR / GAB1 (positive in Shh MBs)

Classification of medulloblastomas using immunohistochemistry

anti-ß-Catenin anti-Yap1 anti-p75 NGFR anti-Otx2

+ + +

+ + -

--

-

-

- +

Can the “4 biological subgroup“ model used for clinical decision making ?

Taylor et al., Acta NP, 2012

Progenitor cells

classic MB MB with extensive nodularity

Desmoplastic/nodular MB

WNT activation

Mutation CTNNB1

Monosomy 6

Hedgehog activation

Mutation PTCH1, SUFU, SMO

LOH 9q, LOH 10q

Loss 17p

Gain 17q

others

myc amplification

others

EGLventricular

matrix

large cell MB / anaplastic MB

cpa /midline

tumorshemispheric or

midline tumors

lower rhombic lip

MycN-GLI2 amplif.

loss TP53

classic MB

“Medulloblastoma“ represents five different diseases

midline

tumors

Anaplastic medulloblastoma with p53 accumulation:

Indication of possible Li-Fraumeni syndrome

p53

Chromotripsis of chromosome 13

SHH-p53 genomic instability

Histological features: focal/diffuse anaplasia, desmoplasia, p53 accumulation

Medulloblastoma, histologically defined

Medulloblastoma, classicMedulloblastoma, desmoplastic/nodularMedulloblastoma with extensive nodularityMedulloblastoma, large cell/anaplastic

Medulloblastoma, genetically defined

Medulloblastoma, WNT-activatedMedulloblastoma, SHH-activated, TP53 mutated Medulloblastoma, SHH-activated, TP53 wild-typeMedulloblastoma, non-WNT/non-SHH

Medulloblastoma, Group 3 Medulloblastoma, Group 4

Medulloblastoma, NOS

WHO Classification 2016

Do methylation / expression groups represent disease entities ?

Taylor et al., Acta NP, 2012

Pietsch et al., Acta NP 2014

Group 3 / Group 4 subgroups are overlapping and confluent variantsof non-WNT/non-SHH medulloblastomas

Northcott et al., Nature 2017

Medulloblastoma, histologically defined

Medulloblastoma, classicMedulloblastoma, desmoplastic/nodularMedulloblastoma with extensive nodularityMedulloblastoma, large cell/anaplastic

Medulloblastoma, genetically defined

Medulloblastoma, WNT-activatedMedulloblastoma, SHH-activated, TP53 mutated Medulloblastoma, SHH-activated, TP53 wild-type Medulloblastoma, non-WNT/non-SHH

Medulloblastoma, Group 3*Medulloblastoma, Group 4*

Medulloblastoma, NOS* provisional variants

WHO Classification 2016

Survival analysis – expression/methylation groupsRNA sequencing – HIT series

Survival Analysis - Expression Groups

Years

0 2 4 6 8 10 12

Overa

ll S

urv

ival

0,0

0,2

0,4

0,6

0,8

1,0 WNT

SHH

Grp4

Grp3

Survival analysis – expression/methylation groups

Survival Analysis - Expression Groups

Years

0 2 4 6 8 10 12

Overa

ll S

urv

ival

0,0

0,2

0,4

0,6

0,8

1,0

Survival Analysis - Expression groups / MYC amplification

Years

0 2 4 6 8 10 12

Ove

rall

Su

rviv

al

0,0

0,2

0,4

0,6

0,8

1,0

c-MYC amplified

Biomarkers

- diagnostic

- prognostic

- predictive

Taylor et al., Acta NP, 2012

Consensus expression / methylation subgrouping 2012

Progenitor cells

classic MB MB with extensive nodularity

Desmoplastic/nodular MB

WNT activation

Mutation CTNNB1

Monosomy 6

Hedgehog activation

Mutation PTCH1, SUFU, SMO

LOH 9q, LOH 10q

Loss 17p

Gain 17q

others

myc amplification

others

EGLventricular

matrix

large cell MB / anaplastic MB

midline

tumorshemispheric or

midline tumors

lower rhombic lip

MycN-GLI2 amplif.

loss TP53

cerebello-

pontine

angle

classic MB

Medulloblastoma entities – WHO 2016

Medulloblastoma, histologically defined

Medulloblastoma, classicMedulloblastoma, desmoplastic/nodularMedulloblastoma with extensive nodularityMedulloblastoma, large cell/anaplastic

Medulloblastoma, genetically defined

Medulloblastoma, WNT-activatedMedulloblastoma, SHH-activated, TP53 mutated Medulloblastoma, SHH-activated, TP53 wild-type Medulloblastoma, non-WNT/non-SHH

Medulloblastoma, Group 3 Medulloblastoma, Group 4

Medulloblastoma, NOS

>>> Integrated diagnosis !!

WHO Classification 2016

Medulloblastoma, histologically defined

Medulloblastoma, classicMedulloblastoma, desmoplastic/nodularMedulloblastoma with extensive nodularityMedulloblastoma, large cell/anaplastic

Medulloblastoma, genetically defined

Medulloblastoma, WNT-activatedMedulloblastoma, SHH-activated, TP53 mutated Medulloblastoma, SHH-activated, TP53 wild-type Medulloblastoma, non-WNT/non-SHH

Medulloblastoma, Group 3 Medulloblastoma, Group 4

WHO Classification 2016

>> To diagnose medulloblastoma according to WHO-Classifikation 2016,

1) WNT- and SHH-activated tumors have to be identified,

2) in SHH-activated tumors, TP53 mutational status must be determined.

Thank you !

neuropath@uni-bonn.de