De differentiaal diagnose tussen diffuus grootcellig B-cel lymfoom en Burkitt lymfoom. Dr. King H. Lam Afd. Pathologie

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1 De differentiaal diagnose tussen diffuus grootcellig B-cel lymfoom en Burkitt lymfoom Dr. King H. Lam Afd. Pathologie

2 Overzicht Inleiding in Burkitt lymfoom (BL) en diffuus grootcellig B-cel lymfoom (DLBCL) Het verschil tussen BL en DLBCL in de dagelijkse praktijk Het verschil tussen BL en DLBCL op moleculair niveau Het leven in een imperfecte wereld (veel dia s in het Engels)

3 Origine BL en DLBCL aan de hand van lymfklier microanatomie Cortex (B-cel gebied) Mantel zone and kiemcentrum: Follikels Memory B-cells: Marginale zone Macrofagen and folliculair dendritische cellen: antigeen presenterende cellen Paracortex (T-cel gebied) T-cel immunoblastaire reactie met T-helper/cytotoxische T-cellen Interdigiterende dendrische cellen/macrofagen: antigeen presenterende cellen Medulla Plasmacellen in mergstrengen Warnke RA et. al. Tumors of the Lymph Nodes and Spleen. Vol. 14 American Registry of Pathology, Washington, 1995

4 Relatieve frequentie B-cel NHL Swerdlow SH et al. WHO classification of tumours of haematopoietic and lymphoid tissues. IARC. Lyon 2008

5 Burkitt s Lymphoma (BL) Endemic in Africa (EBV related) Children and Young adults (Western hemisphere) ENT area and abdominal Diffuse pattern with tingible body macrophages (starry sky pattern) Medium sized cells often with vacuolated cytoplasm, uniform nuclear aspect, variants described. Germinal centre characteristics. CD 79a+, CD 20+, CD 10+, BCL6+, IgM Lambda, TdT-, MIB-1 almost 100%+ 20% BCL2-/+, almost none BCL6- (acceptable only if morphology fits), BCL2- and MYC+ t(8;14) MYC oncogene is over-expressed by the IgH promotor, others t(2;8) and t(8;22)

6 Diffuse Large Cell Lymphoma (DLBCL) Older patients and HIV infected patients Disseminated in many lymph nodes or extra-nodal Diffuse pattern in HE Large cells (centroblasts, immunoblasts) CD 79a+, CD 20+, Some times CD 5+ t(14;18) / Bcl-2 in 30% of the cases t(3;14) / Bcl-6 in 30% of the cases 10% MYC+

7 DLBCL / Sub-types Centroblastic / immunoblastic Anaplastic / plasmacytoid (CD 30+, ALK-1+) WHO 2008: Plasmablastic often immunoblasts, EBV+, IH of plasma cells, oral cavity, HIV, elderly T-cell rich large B cell Lymphoma (WHO 2008: greyzone with NLPHL) Primary mediastinal (thymic) with sclerosis (WHO 2008: greyzone with CHL) Primary effusion lymphoma Intravascular large B-cell lymphoma Lymphomatoid granulomatosis WHO 2008: EBV related DLBCL of the elderly 8-10% of DLBCL Median age 71 70% extranodal Large, polymorhic cell type (RS-like) EBER+, EBV-LMP+, EBNA-1+, CD30+, CD15-

8 De theorie: morfologie Burkitt lymfoom vs DLBCL Compact 2-dimensionaal groeipatroon, meestal weinig fibrose Middelgrote cellen (1,5-2x diameter lymfocyt) Kernen met vrij egaal chromatinepatroon, 1-4 kleine nucleoli Hoog aantal delingsfiguren Veel sterrenhemel macrofagen Compact 3-dimensionaal groeipatroon, soms veel fibrose Grote cellen (2-2,5x diameter lymfocyt) Kernen met blazig aspect, grof chromatine, 1-2 grote nucleoli, centro- /immunoblasten Meestal een wat lager aantal delingsfiguren Meestal weinig sterrenhemel macrofagen

9 De praktijk: histologie BL vs DLBCL

10 De praktijk: cytologie BL vs DLBCL Courtesy of Dr. Kirsten van Lom, Dept. of Hematology

11 Burkitt immunohistochemie: CD20+, CD10+, BCL6+, MUM1-/+, BCL2- Ki-67+ (+/- 100%) HE CD10 Mib-1 TdT / BCL2

12 Onderscheid niet altijd duidelijk te maken.. BL DLBCL Er zijn ook DLBCL met CD20+, CD10+, BCL6+, MUM1-/+, BCL2- en Ki-67+ (+/- 100%)! BL?/DLBCL?

13 Common translocations in malignant lymphoma van Dijk et al. Translocation detection in lymphoma diagnosis by split-signal FISH: a standardised approach. J Hematopathol 1: (2008)

14 Translocations Burkitt s lymphoma

15 Complicating the story (1)

16 Methods 220 mature aggressive B-cell lymphomas, including a core group of 8 Burkitt s lymphomas that met all World Health Organization (WHO) criteria Gene-expression profiling using Affymetrix U133A GeneChips with RNA extracted from frozen samples A molecular signature for Burkitt s lymphoma was generated Chromosomal abnormalities were detected with interphase fluorescence in situ hybridization and array-based comparative genomic hybridization. Hummel et al. A biologic definition of Burkitt s lymphoma from transcriptional and genomic profiling. New England J of Med 354 (23): (2006)

17 Results 44 cases with molecular signature for Burkitt s lymphoma: 11 with diffuse large-b-cell lymphoma morphology, 4 are unclassifiable mature aggressive B-cell lymphoma 29 had a classic or atypical Burkitt s morphologic appearance. 5 did not have a detectable IG-myc Burkitt s translocation, 39 contained an IG-myc fusion, mostly in simple karyotypes. 176 lymphomas without the molecular signature for Burkitt s lymphoma: 155 were diffuse large-b-cell lymphomas: 21 % with chromosomal breakpoint at the myc locus associated with complex chromosomal changes and an unfavorable clinical course. Hummel et al. A biologic definition of Burkitt s lymphoma from transcriptional and genomic profiling. New England J of Med 354 (23): (2006)

18 Results Hummel et al. A biologic definition of Burkitt s lymphoma from transcriptional and genomic profiling. New England J of Med 354 (23): (2006)

19 Clinical significance Hummel et al. A biologic definition of Burkitt s lymphoma from transcriptional and genomic profiling. New England J of Med 354 (23): (2006)

20 Complicating the story (2)

21 Methods Tumor-biopsy specimens from 303 patients with aggressive lymphomas Profiled for gene expression Classified according to morphology immunohistochemistry detection of the t(8;14) c-myc translocation Sandeep et al. Molecular diagnosis of Burkitt s lymphoma. New England J of Med 354 (23): (2006)

22 Results Sandeep et al. Molecular diagnosis of Burkitt s lymphoma. New England J of Med 354 (23): (2006)

23 Results Sandeep et al. Molecular diagnosis of Burkitt s lymphoma. New England J of Med 354 (23): (2006)

24 PA: DLBCL vs Molecular: BL Sandeep et al. Molecular diagnosis of Burkitt s lymphoma. New England J of Med 354 (23): (2006)

25 DLBCL with MYC+ > Molecular DLBCL Sandeep et al. Molecular diagnosis of Burkitt s lymphoma. New England J of Med 354 (23): (2006)

26 Results A classifier based on gene expression correctly identified all 25 pathologically verified cases of classic Burkitt s lymphoma. Burkitt s lymphoma was readily distinguished from diffuse large-b-cell lymphoma by the high level of expression of c-myc target genes, the expression of a subgroup of germinal-center B-cell genes, and the low level of expression of major-histocompatibility-complex class I genes and nuclear factor-κb target genes. Eight specimens with a pathological diagnosis of diffuse large-b-cell lymphoma had the typical gene-expression profile of Burkitt s lymphoma, suggesting they represent cases of Burkitt s lymphoma that are difficult to diagnose by current methods. Among 28 of the patients with a molecular diagnosis of Burkitt s lymphoma, the overall survival was superior among those who had received intensive chemotherapy regimens instead of lower-dose regimens. Sandeep et al. Molecular diagnosis of Burkitt s lymphoma. New England J of Med 354 (23): (2006)

27 N=28 molecular BL with complete clinical FU Sandeep et al. Molecular diagnosis of Burkitt s lymphoma. New England J of Med 354 (23): (2006)

28 WHO 2008: BL vs DLBCL Characteristics BL: IgM+, Lambda+, TdT- GC characteristics: CD10+, BCL6+, CD38+, CD77+ Ki-67: 100% Ig hypermutated, no class switch 85% t(8;14); other t(2;8) and t(8:22) Genetically simple malignancy, no complex karyotype

29 WHO 2008: gray zone DLBCL / BL Intermediate chapter WHO 2008: Keep DLBCL and BL categories clean Prevent patients needing more only get R-CHOP Classification problems in practice: 2-5% DLBCL have features consistent with BL There are lymphoma s with BL morphology, MYC translocation and aberrant phenotype, such als BCL2+ Typical BL morphology and phenotype but no MYC translocation BL / atypical BL with MYC+ and BCL2+ and/or BCL6+ and/or CCND+ Adapted from Dr. Ph.M. Kluin, Dept. of Pathology, University Medical Center Groningen

30 WHO 2008: gray zone DLBCL / BL 2-5% DLBCL have features consistent with BL: Morphology classical or monomorphic Ki-67: 100%, CD10+, BCL2+, MUM-1+/-, 30-40% MYC+ Check IgH+, IgL+ of IgK+ partner: BL, clinical correlation, other FISH studies (exclude complex karyotype) There are lymphoma s with BL morphology, MYC translocation and aberrant phenotype, such als BCL2+: 20% of BL have some BCL2 expression Double hit / other mechanisms that give aberrant BCL2 expression Exclude double hits (BCL2, BCL6, CCND) If all other data are typical (only BCL2+ in IH): call it BL Adapted from Dr. Ph.M. Kluin, Dept. of Pathology, University Medical Center Groningen

31 WHO 2008: gray zone DLBCL / BL Typical BL morphology and phenotype but no MYC translocation: 10% have no breakpoint Technical reason: breakpoint to far away for probe set Biological reason: some cases have a little more complex karyotype Incorrect diagnosis: use multiple probe tests, karyotype for complexity, accept as BL only if this is the only aberrant finding BL / atypical BL with MYC+ and BCL2+ and/or BCL6+ and/or CCND+: Origen probably VDJ recombination by RAG 1/2. If BCL2 strongly +: look for BCL2 and BCL6 rearrangements. DLBCL with MYC+; look for other breakpoints Usually BCL2+ and MYC+ Higher age groups Each BL with BCL2+ in IH: FISH and karyotyping BCL2- is not specific for BL!! Adapted from Dr. Ph.M. Kluin, Dept. of Pathology, University Medical Center Groningen

32 WHO 2008: B-cell lymphoma unclassifiable with features between DLBCL and BL Not an entity BL-like morphology with more or less large cells Variabel proliferation rate BCL2 expression variable, often + MYC often + Complex karytype common Including double hit lymphoma s: MYC+ and BCL2+ /BCL6+

33 Conclusies Het verschil tussen een Burkitt lymfoom en diffuus grootcellig B-cel lymfoom is meestal, maar niet altijd te maken met de klinische presentatie, morfologie (cytologie en histologie), immunofenotypering (immunohistochemie en flowcytometrie). Uitbreiding met cytogenetica helpt men in de meeste gevallen wel verder. Genexpressie arrays lijken in principe de gouden standaard, maar in de dagelijkse klinische praktijk nog moeilijk te realiseren Overwogen moet worden om betrokkenheid van het MYC gen bij elke diffuus grootcellig B-cel NHL na te gaan met FISH en dan de therapie hierop aan te passen