!
THIERRY(MOLINA((PARIS)(
(
DIAGNOSTICS(
Department(of(Pathology,(Necker(Hospital,(APHP>Centre,(Imagine(Institute,(University(of(Paris(
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Diffuse!large!B>cell!Lymphoma!(DLBCL)!is!a!very!heterogeneous!entity!comprising!more!than!
20!entities!according!to!WHO!2016!Classification.!The!most!frequent!entity!called!DLBCL!NOS!
(Not! otherwise! Specified)! is! diagnosed! after! having! excluded! all! the! other! entities! and! is!
divided! in! two! subtypes! in! the! 2016! WHO! Classification:! Germinal! center! B>cell! like! (GCB)!
and! Activated! B>cell! like! (ABC)! better! defined! by! gene! expression! than!
immunohistochemistry.! Patients! with! ABC! DLBCL! have! a! worse! prognosis! than! GCB! DLBCL!
when! treated! with! Rituximab>CHOP.! However,! molecular! studies! underlined! recently! that!
DLBCL! NOS! is! much! more! heterogeneous! than! only! comprising! two! subtypes! and! may!
comprise!at!least!5!to!7!subtypes,!potentially!explaining!the!failure!of!recently!implemented!
targeted! therapy! phase! 3! trials! in! DLBCL.! Through! some! clinical! cases,! we! will! detail! new!
entities! from! the! WHO! 2016! such! as! High>grade! B>cell! lymphoma,! with! MYC! and! BCL2!
and/or!BCL6!rearrangements,!High>grade!B>cell!lymphoma,!NOS,!Large!B>cell!lymphoma!with!
IRF4! rearrangement! as! well! as! Primary! Mediastinal! Large! B>cell! Lymphoma.! It! is! very!
important! to! differentiate! the! rare! double! Hit! aggressive! B>cell! lymphoma! (more! often!
translocations!involving!MYC!on!one!hand!and!BCL2!genes!on!the!other!hand)!from!the!large!
group! of! double! expressor! DLBCL! linked! to! overexpression! of! MYC! and! BCL2! proteins.!!
Double!hit!DLBCL!are!GCB!subtype!whereas!double!expressor!DLBCL!are!mainly!associated!
with! ABC! subtype.! Primary! Mediastinal! large! B>cell! Lymphoma! is! sometimes! difficult! to!
differentiate! from! DLBCL! NOS! and! molecular! tools! may! help! a! lot! for! better! defining! this!
entity!which!is!managed!differentially!to!DLBCL!NOS!at!least!in!some!countries.!Interestingly,!
Extramediastinal! PMBL! are! now! defined! and! represent! a! diagnostic! challenge! and! need!
ancillary! tools! to! be! able! to! recognize! this! entity.! We! will! underline! the! importance! of!
molecular!studies!from!Formalin>fixed!paraffin>embedded!samples!such!as!FISH!or!targeted!
gene!expression,!NGS,!to!better!classify!DLBCL.!
!R
eferences(:((
Swerdlow!SH,!et!al.!WHO!Classification!of!Tumours!of!Haematopoietic!and!Lymphoid!Tissues,!IARC,!
Lyon,!2017.!
Bobee! V! et! al! .! Determination! of! Molecular! subtypes! of! Diffuse! large! B>cell! Lymphoma! using! a! RT>
MLPA!Classifier!.!A!CALYM!study.!J!Mol!Diagn,!2017,!19,!892>904!
Chapuy! B! et! al.! Molecular! subtypes! of! diffuse! large! B>cell! lymphoma! are! associated! with! distinct!
pathogenic!mechanisms!and!outcome.!Nat!Med,!2018,!24,!679>90.!
Wright! GW! et! al.! A! probabilistic! classification! tool! for! genetic! subtypes! of! diffuse! large! B>cell!
lymphoma!with!therapeutic!implications.!Cancer!Cell,!2020,!37,!551>68.!
Yuan!J!et!al.!Identification!of!Primary!Mediastinal!Large!B>cell!Lymphoma!at!Non_mediastinal!sites!by!
gene!expression!profiling.!Am!J!Surg!Pathol,!2015,!39,!1322>1330.!
Wang! Y! et! al.! Amplification! of! 9p24.1! in! DLBCL! identifies! a! unique! subset! of! cases! that! resemble!
PMBL.!Blood!cancer!Journal,!2019,!9:73.!
Pasqualucci!L!and!Dalla>Favera!R.!Genetics!of!diffuse!large!B>cell!lymphoma.!Blood,!2018,!131,!2307>
19.!
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SCIENTIFIC PROGRAMME
SESSION I
HODGKIN’S DISEASE
DEBATE I
IS THERE STILL A ROLE
FOR COMBINED MODALITY
THERAPY FOR EARLY
STAGE CHL?
SESSION II
T-CELL LYMPHOMA
ROUNDTABLE I
FUTURE DIRECTIONS IN
T-CELL LYMPHOMA
SESSION III
FOLLICULAR LYMPHOMA
DEBATE II
CAN WE AVOID
CHEMOTHERAPY IN
THE MANAGEMENT OF
FOLLICULAR LYMPHOMA?
SESSION IV
RARE LYMPHOMAS –
MARGINAL ZONE
LYMPHOMA AND
WALDENSTRÖM M
ACROGLOBULINEMIA
ROUNDTABLE II – WHERE
TO GO IN RARE B-CELL
LYMPHOMAS
SESSION V
MANTLE CELL LYMPHOMA
SESSION VI
DIFFUSE LARGE B-CELL
LYMPHOMA
DEBATE III
DO WE STILL NEED ASCT
IN MCL?
SESSION VII
NOVEL THER APEUTIC
CONCEPTS IN B-CELL
LYMPHOMAS
SELECTED ABSTRACTS
FOR AN ORAL
PRESENTATION
SELECTED ABSTRACTS
FOR A POSTER
PRESENTATION
DISCLOSURES