Case Of Burkitt's Lymphoma Research Articles

Molecular genetics of aggressive B-cell lymphoma.

Molecular genetics of aggressive B-cell lymphoma.

The importance of CD39, CD43, CD81, and CD95 expression for differentiating B cell lymphoma by flow cytometry.

B cell lymphomas' (BCL) current diagnosis is usually based on a combination of morphology, immunophenotype, recurrent cytogenetic aberration and clinical features. However, even with these diagnostic tools, a definitive diagnosis can be difficult to achieve. Therefore, the aim of this study was to assess the profile of CD39, CD43, CD81, and CD95 expressions in diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), and Burkitt lymphoma (BL) cases. To address this issue, we investigated the expression of CD39, CD43, CD81, and CD95 by eight-color flow cytometry in retrospective cases from 2014 to 2016. The study included 27 adult patients diagnosed with DLBCL, FL, and BL during the study period. Four patients were diagnosed with germinal center B cell-like DLBCL (GCB DLBCL), seven with non-GCB DLBCL, nine with FL, and seven with BL. CD39 seems to be especially relevant to differentiate non-GCB DLBCL from BL and from FL. BL showed stronger expression of CD43 when compared to FL and GCB DLBCL. Moreover, CD43 may help to distinguish non-GCB DLBCL from GCB DLBCL. CD81 expression was much stronger in BL when compared to the other three groups of patients. Lastly, CD95 may also help to distinguish BL from the other subtypes, as BL cells expressed this antigen at low levels. In combination, CD39, CD43, CD81, and CD95 expressions appear to be helpful to distinguish CD10+ BCL, particularly BL. Phenotypic distinction between FL and GCB DLBCL remains challenging and requires further studies. © 2017 International Clinical Cytometry Society.

Primary Burkitt lymphoma of the supraglottic larynx: a case report and review of the literature

BackgroundBurkitt lymphoma is a high-grade B cell lymphoma which accounts for less than 1% of all adult cases of non-Hodgkin lymphoma. Rare instances of Burkitt lymphoma developing secondary to prior irradiation have been described in the literature.Case presentationWe report a case of a 90-year-old white woman with a recent history of irradiation for Hodgkin lymphoma, who presented with primary Burkitt lymphoma of the supraglottic larynx. She underwent emergency awake tracheostomy with biopsy. A histopathological examination confirmed non-Hodgkin, B cell lymphoma of Burkitt type. Given her age and poor functional status, she underwent treatment with palliative radiotherapy.ConclusionsA literature review was performed to clarify the clinical characteristics of radiation-induced Burkitt lymphoma in the head and neck, as well as its diagnosis and management. The present case represents the second case of radiation-induced Burkitt lymphoma in the head and neck in the reported literature, and the first in the supraglottic larynx. It highlights the need to maintain a broad differential in the assessment of malignancies of the larynx, particularly in patients with a prior history of radiation treatment.

Prognostic Impact of MUM1/IRF4 Expression in Burkitt Lymphoma (BL): A Reappraisal of 88 BL Patients in Japan.

MUM1/IRF4 expression is detected in 18% to 41% of Burkitt lymphoma (BL). However, only a few studies of MUM1-positive (MUM1) BL have been reported, and its characteristics still remain controversial. To highlight the features of MUM1 BL, we compared the clinicopathologic characteristics of 37 cases of MUM1 and 51 cases of MUM1-negative (MUM1) BL in Japan. Compared with MUM1 BL, patients with MUM1 BL showed significantly younger onset (P=0.0062) and a higher ratio of females (P=0.013). We have also revealed the difference in the involved sites. The MUM1 group showed lower incidences of involvement of stomach (P=0.012) and tonsil (P=0.069). There was a more tendency in MUM1 group to involve colon (P=0.072), breast (P=0.073), and kidney (P=0.073). Regarding the prognosis, a trend toward a lower overall survival for MUM1 group was noted (P=0.089). Notably, comparing MUM1 and MUM1 BL cases of adults (age16 y old and above), the former showed significantly worse prognosis (P=0.041). Among the BL patients treated with the intensive chemotherapy, a standard therapy for BL, MUM1 cases showed worse prognosis (P=0.056). In conclusion, MUM1 BL showed worse prognosis, particularly in adult cases, compared with MUM1 BL. In addition, the difference of the onset age, sex ratio, and involved sites between the 2 groups was noted. Our results demonstrate that MUM1 expression might predict worse prognosis of BL, and MUM1 BL should be distinguished from MUM1 BL.

Comprehensive Metaboproteomics of Burkitt's and Diffuse Large B-Cell Lymphoma Cell Lines and Primary Tumor Tissues Reveals Distinct Differences in Pyruvate Content and Metabolism.

Burkitt's lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) are pathologically and clinically distinct subtypes of aggressive non-Hodgkin B-cell lymphoma. To learn more about their biology, we employed metabolomic and proteomic methods to study both established cell lines as well as cryopreserved and formalin-fixed paraffin-embedded (FFPE) tissue sections of BL and DLBCL. Strikingly, NMR analyses revealed DLBCL cell lines to produce and secrete significantly (padj = 1.72 × 10-22) more pyruvic acid than BL cell lines. This finding could be reproduced by targeted GC/MS analyses of cryopreserved tissue sections of BL and DLBCL cases. Enrichment analysis of an overlapping set of N = 2315 proteins, that had been quantified by nanoLC-SWATH-MS in BL and DLBCL cultured cells and cryosections, supported the observed difference in pyruvic acid content, as glycolysis and pyruvate metabolism were downregulated, while one-carbon metabolism was upregulated in BL compared to DLBCL. Furthermore, 92.1% of the overlapping significant proteins showed the same direction of regulation in cryopreserved and FFPE material. Proteome data are available via ProteomeXchange with identifier PXD004936.

Diagnostic Dilemma in the Morphological Detection of Flower Cells in Lymphomas.

"Flower cells" are described typically in HTLV-1 induced adult T cell leukemia. Very few case reports have been published documenting flower cells in B cell lymphomas. We herein present a case of Burkitt lymphoma proven on the basis of immunophenotyping and FISH studies, with "flower cells" morphology.

A case of primary Burkitt lymphoma of the appendix

A case of primary Burkitt lymphoma of the appendix

Comprehensive Genomic Analysis of Adult Burkitt Lymphoma Identifies the B-Cell Receptor Signaling Pathway As a Potential Therapeutic Target

Burkitt lymphoma (BL) is the most common non-Hodgkin lymphoma (NHL) in children. Although it accounts for only 1-5% of NHL in adults, approximately 60% of the BL cases diagnosed each year in western countries occur in patients >40 years of age. Although adult and pediatric BL cases are indistinguishable by molecular classification, pediatric patients have a significantly better outcome than adults. While translocation of MYC to the immunoglobulin heavy or light chain genes is characteristic of pediatric and adult BL, genetic differences may contribute to the superior clinical outcome of childhood cases.Therefore, we aimed to identify the spectrum of additional genetic abnormalities that occur in adult and pediatric BL. Copy number analysis, gene expression profiling (GEP), and targeted sequencing of ~400 genes known to be mutated in NHLs were performed on a cohort of molecularly defined BL samples. Copy number abnormalities (CNAs) were identified by the Affymetrix 250k NspI SNP array in 73 BL tumors (28 adult, 45 pediatric), and sequencing was performed on 52 BLs (21 adult, 31 pediatric). Pediatric cases had fewer CNAs than adults. The most common focal abnormality identified was a gain on 13q31.3 encompassing MIR17HG. It was more frequent in adult compared to pediatric cases (35% vs 16%, p=0.085) and was associated with increased expression of miR-17~92 cluster members; and among adults, patients with this gain trended towards worse overall survival, though the number of cases with available information was small. Gain of 8q was found in ~20% of adult cases, but in no pediatric cases. Surprisingly, cases with 8q gain had significantly lower MYC mRNA expression (p< 0.001) and lower protein expression. In cases with MYC gain 0/4 cases were positive for MYC protein expression by immunohistochemistry; in contrast,6/10 cases with no MYC gain were positive for MYC expression. This suggests that gain of 8q is driven by another gene in the region. Additional genetic alterations included gains of genomic loci encompassing MCL1 and MDM4 (1q21-24) and losses encompassing RB1, p53 and CDKN2A/CDKN2B. Pathway analysis of genes differentially expressed by CN status showed an enrichment of genes involved in cell cycle regulation, the p53 signaling pathway, and the ubiquitin proteasome pathway.The frequencies of mutations in commonly mutated genes including MYC, ID3, TP53, CCND3, DDX3X, ARID1A, and TCF3 were not significantly different in adult and pediatric BL. However, BCL2, (43%, p<0.001), ZFHX3 (24%, p<0.01), SPTBN5 (20%, p=0.02), RB1 (14%, p=0.06), BTG1 (14%, p=0.06), TCF4 (14%, p=0.06), and TNFRSF14 (14%, p=0.06), were exclusively mutated in adult BL. In contrast, mutations in CDH23 (29% vs 5%, p=0.04) and SMARCA4 (35% vs 19%, p=0.05) were more frequent in pediatric BL. When mutations were placed into oncogenic pathways, mutations in genes regulating the PI3K-AKT pathway did not shown significant differences between adult and pediatric cases. Mutations promoting tonic BCR signaling (TCF3 and ID3) by activation of the PI3K pathway had similar frequencies in the two age groups, however, BCR signaling effectors inducing chronic active NF-kB signaling (CD79A, SYK, MYD88, BCL10, CARD11) were significantly associated with adult BL (adult cases with any mutation: 19% vs 7%).Gene expression studies suggested activated BCR signaling in BL cases with CN gain of miR-17~92. In vitro analysis of miR17~92 in BL cell lines (n=4) showed that functional loss of miR-17 ~ 92 expression using a miRNA sponge led to reduced proliferation. Treatment of BL cell lines with anti-IgM induced BCR activation in a time- and dosage-dependent manner, as estimated by increased phosphorylation of downstream mediators (SYK and BLNK). This activation was reduced upon loss of functional miR-17 ~ 92 expression in cell lines. Since miR-17~92 can directly inhibit proximal negative regulators of BCR signaling, treatment with the FDA-approved BTK inhibitor, Ibrutnib, further inhibited proliferation of BL cell lines carrying the miRNA sponge. The BCR signaling pathway is one example of how unique abnormalities in adult BL can provide possible targets for therapeutic intervention. DisclosuresNo relevant conflicts of interest to declare.

Improved Outcome and Decreased Morbidity and Mortality Rates of B-Cell Malignancies with Less Intensive Chemotherapy Induction: Experience in a Single Institution

Background: High-Dose chemotherapy is necessary one of the most important tools for improving response rates and for decreasing relapse rate in childhood B-cell malignancies. However, deaths during induction or in Complete Remission (CR) in children with higher disease burden had adversely influenced pEFS in our setting, and for this reason an accomplished clinical support is mandatory for achieving these better results.Objective: Our aim was to diminish morbidity and mortality of patients with B-cell malignancies with the administration of a reduced intensity BFM-based induction phase, plus the addition of rituximab in a pilot study. We also retrospectively analyzed the outcome of this group of patients.Methods: This is a prospective study, single arm, non-randomized local trial for treatment of B-cell malignancies. Between December-2008 and March-2016, 81 pts consecutive (<16 years/old) (52:M/29:F) were enrolled in a protocol HPG-09, and 70 of them resulted evaluable.Patients were stratified according stage and DHL level in Risk-1, Risk-2, Risk-3 and Risk-4. Risk-4 included patients with stage IV and stage III with DHL levels higher than 1,000 U/dl.The pathology, flow-cytometry and cytogenetic findings disclosed 60 cases of Burkitt Lymphoma, 11 diffuse large B cell Lymphomas, 9 mature-B acute lymphoblastic leukemia, and 1 Precursor-B ALL with with t(8;14).The treatment locally-none BFM-counterpart included 4 doses of Rituximab administered to Risk-4 cases during early phases of treatment and intensified chemotherapy with HDMTX (24 hr) 5 g/m2, plus reduced intensity induction with pre-phase followed by A1 block (MTX 1 g/m2 4 hr infusion), in order to decrease morbidity and early mortality rates.Results: Distribution of patient according to risk-groups was: Risk-1 (n=2) 2%, Risk-2 (n=9) 11%, Risk-3: (n=13) 16% and Risk-4 (n=46) 57% of cases. Median DHL= 3,642 (range: 396-33,673) UI/dl, CNS+ cases was observed in 6 cases. Complete remission (CR) was achieved in 95.1% of the cases and 4.9% of patients died in early phases of treatment. From patient who achieve CR, 6 adverse events were observed (all of them in Risk-4 group): 2 relapses and 4 death in CR (1 Steven´s-Johnson Syndrome, 2 tumor lysis syndrome plus CID and 1 patient died after extensive initial surgery) The pEFS for R1, R2, and R3 was 100%. With a median follow-up of 48 (range:6-61) months, the pEFS (SE) for all risks groups was 91 (4)% and for Risk-4 85 (6)%.Conclusions: Risk-4 group accounted for 66% of the total population of patients, defining a more aggressive disease prevalence in our setting. Locally-adapted strategy based on BFM experience was successfully implemented, reducing induction intensity and with the incorporation of 4 doses of Rituximab. The outcome of this group of patients was very good. Reduction of induction intensity and addition of Rituximab resulted in low mortality rate and excellent survival outcome. DisclosuresNo relevant conflicts of interest to declare.

Burkitt Lymphoma Genome Sequencing Project (BLGSP): Introduction

Introduction: Burkitt Lymphoma (BL) is an aggressive B-cell lymphoma with a translocation involving MYC and immunoglobulin(Ig) loci. It is most common in children, but also affects adults, and occurs in sporadic, endemic and HIV-associated forms. The Epstein-Barr virus (EBV)-associated endemic subtype is the most common pediatric cancer in equatorial Africa, but also occurs in other parts of the world, for example in the rain forest of Brazil. Intensive chemotherapy is effective, but the associated toxicity requires supportive care that is not readily available in resource-poor regions. Previously published molecular characterization of small numbers of tumors indicated that the mutation profiles of endemic and sporadic cases are similar, but not identical. One goal of the BLGSP is to conduct comprehensive molecular characterization of BL by sequencing DNA and RNA from a large BL cohort - including endemic, sporadic, pediatric and adult cases - in order to define the genetic and phenotypic features that drive these cancers. These data will be analyzed with an intent toward developing new therapeutic strategies that can be deployed worldwide.Methods: The goal is to collect 160 BL cases, of which 50% will be endemic, 38% sporadic (pediatric and adult) and 12% from HIV+ patients. For the discovery phase, each tumor requires case-matching normal DNA as well as treatment, outcome and other clinical information. The optimal source of tumor DNA and RNA is from frozen tissue with at least 50% tumor nuclei, but FFPE immobilization is also accepted. Accrual locations include Africa, Brazil, Europe and the US. The BLGSP has developed extensive standard operating procedures for tissue collection, pathology review and tissue processing to reduce the variation associated with these parameters in the interpretation of the results (see https://ocg.cancer.gov/programs/cgci/projects/burkitt-lymphoma). The project also established procedures that allow sharing of all clinical and sample information through the National Cancer Institute Genomic Data Commons (https://gdc.cancer.gov). Molecular characterization includes whole genome sequencing of tumor and normal DNA (80X and 40X coverage, respectively), RNA-sequencing (RNA-seq) and micro-RNA sequencing. These data will enable the BLGSP to identify chromosomal rearrangements, chromosomal copy number alternations, somatic mutations (single nucleotide, insertions, deletions), viral insertions, expression signatures, viral expressions and miRNA regulation of transcripts.Results: To date we have accrued 80 cases of BL of which 75% passed diagnostic pathology review. There was an additional 25% attrition at the tissue processing stage, either due to low quality nucleic acids or low percent tumor nuclei. We have completed sequencing for 45 cases, all but one of which have a MYC translocation involving one of the 3 Ig loci; one case has a MYC rearrangement by FISH analysis that is being characterized further. We have identified recurrent mutations in ID3, DDX3X, ARID1A, FOXO1, TP53, SMARCA4 and other genes. Most mutations are supported by the RNA-seq data, which is also useful in defining the pattern of EBV genome transcription. Preliminary unsupervised hierarchical clustering and principal component analysis of gene expression data defined sample clusters that do not correspond to mutation status or EBV infection, warranting further investigation. Some genes accumulated somatic mutations in a BL subtype-specific fashion.Discussion: BLGSP is an ongoing international collaborative project that will provide a comprehensive molecular portrait of BL subtypes when completed, with the potential to suggest new molecular targets for therapy that can eventually lead to effective treatments that are less toxic than the current regimens. DisclosuresCasper:Janssen: Consultancy, Research Funding; Roche: Consultancy, Other: Travel, Accommodation, Expenses; TempTime: Consultancy, Other: Travel, Accommodation, Expenses; Up to Date: Patents & Royalties; GSK: Other: Travel, Accommodation, Expenses. Abramson:Kite Pharma: Consultancy; Abbvie: Consultancy; Seattle Genetics: Consultancy; Gilead: Consultancy. Noy:Pharmacyclics, LLC, an AbbVie Company: Other: travel, accommodations, expenses, Research Funding.

超音波気管支鏡ガイド下針生検(EBUS-TBNA)により診断したBurkitt lymphomaの1例

超音波気管支鏡ガイド下針生検(EBUS-TBNA)により診断したBurkitt lymphomaの1例

EBV-negative monomorphic B-cell post-transplant lymphoproliferative disorders are pathologically distinct from EBV-positive cases and frequently contain TP53 mutations

AbstractMonomorphic post-transplant lymphoproliferative disorder commonly resembles diffuse large B-cell lymphoma or Burkitt lymphoma, and most are Epstein–Barr virus (EBV) positive. We retrospectively identified 32 cases of monomorphic post-transplant lymphoproliferative disorder from two institutions and evaluated EBV in situ hybridization; TP53 mutation status; p53, CD30, myc, and BCL2 expression by immunohistochemistry; proliferation index by Ki67; and germinal center vs non-germinal center immunophenotype by Hans criteria. Post-transplant lymphoproliferative disorder arose after hematopoietic stem cell transplant in five and solid organ transplant in 27 patients, a median of 4 and 96 months after transplant, respectively (overall median latency 71 months, range 2–295). The most common morphology was diffuse large B-cell lymphoma (28 cases), with three cases of Burkitt lymphoma, and one case of plasmablastic lymphoma. Ten cases (31%) were EBV negative. Of those with the morphology of diffuse large B-cell lymphoma, the EBV-negative cases were more frequently TP53-mutated (P<0.001), p53 positive by immunohistochemistry (P<0.001), CD30 negative (P<0.01), and of germinal center immunophenotype (P=0.01) compared with EBV-positive cases. No statistically significant difference in overall survival was identified based on EBV, TP53 mutation status, germinal center vs non-germinal center immunophenotype, or other immunohistochemical parameters evaluated. Patients who died of post-transplant lymphoproliferative disorder were older with a longer latency from time of transplant to diagnosis (P<0.05). Our study demonstrates that diffuse large B-cell lymphoma-related immunohistochemical prognostic markers have limited relevance in the post-transplant setting and underscores differences between EBV-positive and EBV-negative post-transplant lymphoproliferative disorder in terms of immunophenotype and TP53 mutation frequency, supporting an alternative pathogenesis for EBV-negative post-transplant lymphoproliferative disorder.

The clinical characteristics and outcomes of 16 Burkitt' s lymphoma with testicular involvement

目的总结伴有睾丸侵犯的儿童伯基特淋巴瘤的临床特征，以及应用大剂量甲氨蝶呤（HD-MDX，5~8 g/m2）等联合化疗取代睾丸放疗的临床疗效及预后。方法收集16例伴有睾丸侵犯的伯基特淋巴瘤患儿资料，分析其临床特征，按前瞻性方案设计及分层。全部患儿进入高危组分层治疗，并定期追踪随访。方案采用北京儿童医院淋巴瘤治疗方案中的NHL-BCH-2009-成熟B细胞淋巴瘤方案（来自改良的LMB-89方案联合利妥昔单抗治疗）。结果137例伯基特淋巴瘤患儿中伴睾丸侵犯的患儿16例（11.7%）。16例患儿均为Ⅳ期，中位发病年龄为6.5（2.25~13.5）岁。16例患儿中8例存在骨髓侵犯（其中5例已达白血病期），9例存在中枢神经系统受累（其中5例为中枢神经系统白血病，4例为颅内或脊髓占位）；5例为双侧睾丸侵犯，11例为单侧睾丸侵犯；1例病初存在近期EBV感染（EBV-IgM+）。中位随访时间为31.8(0.5~79.0）个月，16例患儿中死亡2例（1例因早期化疗合并症放弃治疗死亡，1例于早期停药后复发死亡）；1例停药2年8个月后出现膀胱部位肿瘤复发，经治疗目前处于完全缓解；13例无事件生存，无睾丸复发。3年总生存率为87.5%，3年无事件生存率为72.9%。追踪其中>10岁患儿（3例）的睾酮水平，均在正常范围。结论对于伴有睾丸侵犯的伯基特淋巴瘤患儿，为减少放疗的远期不良反应、保留睾丸功能，应用HD-MTX等联合化疗取代睾丸放疗，疗效好，不增加睾丸复发率，性腺功能正常，但远期不良反应及睾丸功能仍有待观察。

Complete Remission of Burkitt Lymphoma After Surgical Excision: A Case Report.

Burkitt lymphoma (BL) is a highly aggressive B cell non-Hodgkin lymphoma that has a high proliferation rate. The prognosis for BL is generally favorable, with cure rate of 75-90% with modern chemoimmunotherapy regimens. Prompt administration of multiagent immunochemotherapy regimens is critical, because BL is almost always fatal if left untreated. Nevertheless here we report a case of BL that is still in complete remission after more than 4years without any further treatment after surgical excision of the involved lymph node.

HIV-associated lymphomas: A clinicopathological study from India

Background: Although there is a high burden of HIV-positive cases in India, there is very little published data on the prevalence and pathological profile of malignancies occurring in these patients. Aims: The current study was undertaken to analyze the clinicopathological profile of HIV-positive patients with Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Materials and Methods: This was a retrospective study over a 6-year period consisting of histopathology slide and clinical chart review of HIV-positive patients with lymphomas. Results: Of a total of 3470 HIV-positive patients during the 6-year period of study, the number of HIV patients diagnosed with lymphomas was 26. The mean duration between HIV seropositivity and development of lymphoma was 12 months. Seven patients were diagnosed as HIV positive during the course of investigations after a lymphoma diagnosis. The male to female ratio was 5.5:1 and the mean CD4 count, 171/mm3. Among the 26 cases, 3 were diagnosed with classical HL and the rest with NHL. B-cell lymphomas predominated with 19 cases. Among the NHLs, plasmablastic lymphoma and diffuse large B-cell lymphoma were the common subtypes with no cases of either Burkitt Lymphoma or primary CNS lymphoma. The median duration of follow-up was 1 year. Ten cases died during the course of treatment, 11 cases achieved complete remission. Conclusions: This is one of the few studies from India documenting the clinicopathological features of HIV-associated lymphomas. It is interesting that in many cases, HIV positivity was detected during the course of investigations after a lymphoma diagnosis.

下唇の痺れを契機として発見されたバーキットリンパ腫の1例

下唇の痺れを契機として発見されたバーキットリンパ腫の1例

Frequency and Clinical Implication of SOX11 Expression in Burkitt Lymphoma

Introduction: The transcription factor SOX11 is normally expressed during embryogenesis in humans. Several studies have shown that SOX11 is aberrantly expressed in various types of haematopoetic and solid malignancies, and appears to affect clinicopathological characteristics. For example, in mantle cell lymphoma, SOX11 serves as a diagnostic antigen and has been shown to be associated with superior outcome (Nordström et al. British Journal of Haematology 2014), although its role as a prognostic indicator remains controversial. In chronic lymphocytic leukemia, SOX11 was associated with inferior overall survival (Roisman et al. Tumor Biol 2015), whereas SOX11 expression correlated with superior outcome in epithelial ovarian cancer (Sernbo et al. BMC Cancer 2011). Various possible target genes and transcriptional programs have been identified, by which SOX11 may exert both repressive, and exaggerative, functions on proliferation, and potentially function as therapeutic targets in the future (Kuo et al. Oncogene 2015, Vegliante et al. Blood 2013). In Burkitt lymphoma (BL), two small series have reported expression of SOX11 in 30-50 % of cases (Mozos et al. Haematologica 2009, Dictor et al. Haematologica 2009). As of yet, no study has been performed specifically to evaluate the implication of SOX11 expression in BL. The aim of this study was to investigate the frequency of SOX11 positive BL cases in a joint cohort from Denmark and Sweden, and correlate its expression to clinical and pathological parameters.Methods: 45 BL cases were collected from Sweden and Denmark. Samples were analysed for expression of SOX11 and other immunohistochemical markers. Cases were classified classic BL or B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and BL (BCLU) after pathology review. Clinical data were obtained from the Danish Lymphoma Database (LYFO) and the Swedish Lymphoma Registry. Additionally, 9 pediatric BL cases were analyzed for SOX11 expression, but with no clinical data available.Results: In the adult BL study population 14/45 (31 %) expressed nuclear staining of SOX11. The SOX11 positive subgroup had a higher median age (53 compared to 41), as well as a larger proportion with elevated LDH. Other prognostic factors were equally distributed between the groups. Although a similar proportion of patients received high-intensive chemotherapy in both subgroups, 3 (21 %) received no treatment in the SOX11 positive cohort. In this BL material, 28 (62 %) were classified classic BL and 17 (38 %) BCLU. There was a significant difference in SOX11 expression between classic BL and BCLU (p=0.03). Among classic BL SOX11 was seen in 12/28 (43 %) whereas in BCLU only 2/17 (12 %) expressed SOX11.Five-year overall survival (OS) in the SOX11 positive group was 57 %, compared to 77 % in the SOX11 negative cohort. When adjusting for treatment, BCLU and prognostic factors in multivariable analysis, no significant difference in outcome was seen between groups (hazard ratio: 2.5 95 % confidence interval: 0.4-13.9, p=0.3). When restricting analysis to classic BL cases only, there was no remaining difference in median age, and no significant difference in OS between SOX11 positive and negative patients in neither univariable nor multivariable analysis. In the pediatric cohort, 5/9 (56 %) expressed SOX11.Conclusion: SOX11 expression was found in less than half of classic BL, and in a small minority of BCLU. In contrast to SOX11 expression in other malignancies, SOX11 expression had no significant impact on outcome, in our cohort, when adjusting for prognostic factors, treatment and BCLU. DisclosuresBrown:Bayer: Consultancy; Roche: Consultancy, Speakers Bureau.

Significance of a Critical Set of 11q Chromosome Aberrations for Diagnosis of MYC Negative Burkitt Lymphoma

Background: Burkitt lymphoma (BL) is characterized by a non-specific morphology and immunophenotype, a high proliferation rate, MYC rearrangements (MYC +), and by a simple karyotype. However, 5% of BL cases have no MYC rearrangements (MYC -) detectable by FISH. It is a matter of debate whether a true MYC (-) BL does exist.The WHO 2008 classification does not clearly define MYC (-) BL cases, and such cases are often misdiagnosed and treated as diffuse large B-cell lymphoma (DLBCL). We have previously described a provisional category of aggressive B-cell lymphoma unclassifiable (BCLU) with recurrent chromosome 11q aberrations, referred to as B-NHL(11q), with clinical, pathomorphological, and gene expression profile features typicalof BL,but MYC (-). B-NHLs(11q) carry proximal gains and telomeric losses of 11q. Karyotyping (CC) and FISH defined the gain region as dup(11)(q23q13) involving CCND1, ATM and KMT2A. As we have recently shown, BL and B-NHL(11q) express different levels of CD38 and CD16&CD56, and both have lower levels of miRNA-155, -21 and -26a than DLBCL. Here we describe a series of BL patients with a set of critical 11q aberrations and propose a diagnostic algorithm for a rapid work-up.Methods: Within a group of 82 BL cases diagnosed and treated with the BL protocol at our institution, we identified 15 cases of B-NHL(11q) with BL features and 11q aberrations: MYC (-) in 11(male/female 10/1, median age [range] 24 [18-62]) and MYC (+) in 4 cases (male/female 3/1, median age [range] 36.5 [20-82]). In MYC (-) pts, the disease was confined to a single site in 82%, was bulky (>7 cm) in 64% with diameter >20 cm in 45% of cases. BL, BCLU and DLBCL diagnosis according to WHO 2008 classification was based on histopathological/immunohistochemical examination (HP/IHC), CC, FISH, and clinical characteristics in all pts. For the final evaluation, the flow cytometry (FCM) immunophenotype, array comparative genomic hybridization (aCGH) data, and miRNA expression was assessed on samples obtained by the fine needle aspiration biopsy (FNAB). In the B-NHL(11q) cases we identified 11q duplication, dup(11q), with an inversion (inv) of the duplicated region and a deletion of its telomeric region, referred to as critical set of 11q aberrations, as opposed to non-critical aberration set that did not involve all three changes. B-NHL(11q) cells were evaluated with the panel of antibodies by IHC (CD20/CD10/BCL6/ BCL2/MUM1/MYC/Ki-67/CD43/CD44), and by FCM with CD (19, 20, 22, 23, 52, 79β, 81, 5, 25, 38, 43, 44, 45, 16&56, 56, 52, 62L, 71, 200), FMC7, HLADR, and BCL2. All B-NHL(11q) cases were evaluated by CC, FISH (MYC, BCL2, BCL6, CCND1, ATM, KMT2A and telomeric 11q) and aCGH. The relative positions of CCND1, ATM, and KMT2A within a duplicated region on the aberrant chromosome 11 were used to identify inversions.Results: A median follow-up of MYC (-) B-NHL(11q) pts treated with the BL regimen was 30 months, and 2-yr OS was 72% (95% CI: 45%, 99%). In 53% of B-NHL(11q) pts tingible body macrophages were less pronounced than in classic BL. All MYC (-) and MYC (+) B-NHLs(11q) cases presented the same phenotype and Ki-67 index of 100% and met the IHC criteria for BL. In MYC (-) and MYC (+) B-NHLs(11q) pts, all with a simple or less simple karyotype, we confirmed a critical or non-critical 11q aberrations in 10 and 5 pts, respectively. In 87% of pts we identified dup(11q), of two types: the larger part between 11q12.1 and 11q24.3 bands, and the smaller part between 11q22.3 and 11q24.1, with an additional multiplication of KMT2A inside the duplication region. In 13% of cases an inv without dup(11q) was detected. We found an inv of dup(11q) region in 73% of all cases, and no inv in dup(11q) in 2 MYC (+) cases only. Bulky tumors of >20 cm correlated with increased KMT2A copy number in B-NHLs(11q)cases.Conclusions: B-NHL(11q) cases are clinically homogenous while 11q aberrations are heterogeneous. We believe that BLs MYC (-) do exist. Combination of HP/IHC with FNAB/FCM/CC/FISH is a reliable method for credible diagnosis of BLMYC (-). BLMYC (-) should only be diagnosed in cases where critical 11q aberrations and a simple karyotype are identified. BCLU(11q) or DLBCL(11q) cases should be diagnosed if there are more complex karyotypes accompanied by 11q aberrations of any type. We hypothesize that in BLMYC (-) and other aggressive B-NHL(11q), 11q aberrations may determine clinical and pathomorphological features equivalent to those resulting from MYC rearrangements. DisclosuresWalewski:Gilead: Consultancy, Honoraria, Other: travel, accommodation; Seattle: Other: travel, accommodation; GSK/Novartis: Research Funding; Genetics: Other: travel, accommodation; Celgene: Honoraria, Other: travel, accommodation, Research Funding; Teva: Consultancy, Honoraria; Servier: Consultancy; Karyopharm: Consultancy; Boehringer Ingelheim: Consultancy; Ariad: Consultancy; Takeda: Consultancy, Honoraria, Other; Roche: Consultancy, Honoraria, Other: travel, accommodation, Research Funding; Sanofi: Honoraria, Other: travel, accommodation; Mundipharma: Consultancy, Honoraria, Research Funding; Janssen-Cilag: Consultancy.

Comparative Analysis of Endemic and Sporadic Burkitt Lymphoma By RNA Sequencing

Introduction: Burkitt lymphoma (BL) is an aggressive B-lineage non-Hodgkin lymphoma that has traditionally been classified into 3 subtypes: "endemic", "sporadic", and HIV-associated. The highest incidence of BL - prompting the "endemic" classification - is observed in children in sub-Saharan Africa, where the distribution of the disease is closely associated with that of P. falciparum malaria. The tumor cells in most cases of BL from sub-Saharan Africa are infected with Epstein Barr virus (EBV). In contrast, a minority of BL tumors from Europe and North America - which are commonly described as "sporadic" - are EBV positive. Although excellent outcomes have been observed for patients with BL treated with multi-agent chemotherapy in Europe and North America, the outcomes of BL patients in sub-Saharan Africa are suboptimal. We hypothesized that improved understanding of the molecular heterogeneity that exists within BL, particularly the molecular features that distinguish cases from sub-Saharan Africa from those from Europe/North America, will enable more effective treatment strategies that can readily be implemented in low-resources settings.Methods: Tumor biopsies were collected from 19 pediatric patients who presented to the Uganda Cancer Institute with maxillofacial tumors histologically confirmed to be BL. Total RNA was extracted and polyA-selected sequencing libraries were prepared. Paired-end, 50-base pair sequencing was performed on the Illumina HiSeq 2500 platform at a depth of 100 million reads per sample. A publicly available RNA sequencing dataset from 28 BL cases from Europe and North America that were previously analyzed by both microarray (NEJM 2006; 354[23]: 2431-2442) and RNA sequencing (Nature 2012; 490[7418]: 116-120) was analyzed in parallel for comparison. RNA sequencing on the 28 sporadic BL tumors was performed on polyA-selected sequencing libraries with paired-end, 108-base pair sequence reads generated on the Illumina HiSeq 2000 platform. The reads from all 47 BL tumors were aligned to the human and EBV (GenBank ID KC207813.1) genomes using the STAR aligner. Tumors were deemed EBV positive if the ratio of mapped viral reads to human reads exceeded 0.001%, since the EBV genome is 0.005% the size of the human genome. Normalization and differential expression analysis were performed on aligned reads using the DESeq2 R package. Somatic variants were identified by the Genome Analysis Tool Kit. Analysis of alterative splicing was performed with the SGSeq R package.Results: All of the Uganda BL cases but only 70% of the previously published European/North American cases were obtained from children less than 18 years; 61% and 87% were from male patients, respectively. One half of patients in both groups presented with Ann Arbor stage I or II disease, while the remainder presented with higher stage disease. The median survival in the 19 Ugandan patients was less than one year. Sequence reads from 15 (79%) of the Ugandan tumors and 4 (15%) of the European/North American tumors aligned to the EBV genome. Although BL is reported to express only latency type I EBV genes, expression of latency type I, II, and III genes was detected. Among the 4 tumors from Uganda that did not contain EBV-derived reads, 1 was from a child who was HIV-seropositive, while the others were from HIV-seronegative patients. Unsupervised hierarchical clustering and principal component analysis of all annotated genes failed to separate EBV positive and EBV negative tumors. Cluster analysis of the Ugandan tumors revealed no association with clinical variables. Ongoing analyses are being performed to identify associations between differentially expressed genes and somatic mutations and alternative splicing that may distinguish the tumor subtypes.Conclusions: While the terms "endemic" and "sporadic" have traditionally been used to classify BL, this nomenclature is archaic and does not accurately capture the underlying biology of the tumor subtypes. We performed a comparative whole transcriptome analysis of BL tumors from patients in Uganda to a dataset of BL tumors from patients in Europe/North America to identify features that distinguish the two cohorts. While cluster analysis failed to clearly separate tumors by their EBV or clinical status, ongoing analyses are being performed to identify alterations that may contribute to their distinct gene expression profiles. DisclosuresNo relevant conflicts of interest to declare.

B Cell Lymphoma Unclassifiable, with Features Intermediate Between Diffuse Large B Cell Lymphoma and Burkitt Lymphoma and Diffuse Large B Cell Lymphoma NOS with Doble/Triple Translocations: Immunophenotypic Analysis

Background: Diffuse large B-cell lymphoma (DLBCL) is a clinically and molecularly heterogeneous disease. We can identify two subgroups with aggressive clinical course and higher risk of treatment failure after standard therapy: B cell lymphoma unclassifiable (BCLU) with features intermediate between DLBCL and Burkitt lymphoma (BL) and B-cell lymphomas with double/triple translocation (DHL/THL). Previous reports suggest that these types of lymphomas may show a common immunophenotype, providing another tool in the challenge of their diagnosis.Objetives: To analyze the immnunophenotype (IF) of BCLU and DH/TH lymphomas by multiparametric flow cytometry and compare it with the IF of a series of cases with DLBCL and BL.Methods: we analyzed the inmunophenotype (four-color flow cytometry on a FACSCalibur flow cytometer) and cytogenetic studies (FISH to detect MYC, BCL2 and/or BCL6 rearrangement) of cases diagnosed of BCLU and DH/TH lymphomas. Control cases of DLBCL and BL were consecutively collected from our database. Fisher`s Exact test was used to compare proportions between two groups. P-values <0.05 were considered statistically significant.Results: We analyzed 23 controls (14 DLBCL and 9 BL) and 17 cases: 9 DHL (8 BCL2/MYC+ and 1 BCL6/MYC+), 3 THL (BCL2/BCL6/MYC+) and 5 BCLU (1 IGH-MYC+, 3 MYC+ and 1 unknown). Six of the 17 cases (35.3%) had decreased expression of CD19 while this was exceptional in DLBCL (1/10 P=0.073) and BL (0/9 P=0.054). All of the cases were positive for CD20 but with different intensities: only 5.9% expressed high CD20 compared to 42.9% of DLBCL (p=0.021) and 55.6% of BL (P=0.010). Most of the cases (12/17) had intermediate expression of CD20 and only 4/17 had weak expression. CD10 expression was typical in BL (100%) and frequent in the cases (82.4%), while it was only present in 20% of DLBCL (P<0.0001). CD38 expression was high in 100% of BL, 6.3% of the cases and none of DLBCL. It was intermediate in 64.7% of the cases and in 35.7% of DLBCL (P=0.015). BCL2 overexpression was detected in 57.1% of the cases; neither DLBCL nor BL (P= 0.009) had BCL2 overexpression.Conclusions: We identify a common immunophenotype in DH/TH lymphomas and BCLU: decreased expression of CD19 and CD20, CD10 expression, overexpression of BCL2 and intermediate expression of CD38. This immuphenotype may be useful for identifying cases for confirmatory cytogenetic studies. Larger studies are needed to validate these results. DisclosuresNo relevant conflicts of interest to declare.