Splenic Marginal Zone Lymphoma and Other Small B-Cell Lymphomas

Author(s):  
Haipeng Shao
Hematology ◽  
2017 ◽  
Vol 2017 (1) ◽  
pp. 371-378 ◽  
Author(s):  
Catherine Thieblemont

Abstract Splenic marginal zone lymphoma (SMZL) and nodal marginal zone lymphoma (NMZL) are rare indolent chronic B-cell lymphomas. Prognosis is typically good with median survival around 10-15 years. Management is generally based on the presence of symptoms or high tumor burden. There are no standard treatments for these 2 entities, and therapeutic strategies are rapidly evolving. Clinical developments for these 2 entities are oriented by genomic studies, with largely overlapping mutational profiles involving the NOTCH, B-cell receptor (BcR) and nuclear factor κB (NF-κB) signaling, chromatin remodeling, and the cytoskeleton. Although new therapeutic options based on targeting signaling pathways and overcoming resistance are increasingly available, few specific prospective studies are performed for these rare subtypes, limiting the conclusions that can be drawn. Novel drugs targeting B-cell signaling have shown promise, including ibrutinib and copanlisib. The second-generation oral immunomodalator (IMiD) lenalidomide showed impressive results when combined with rituximab. Other potential solutions include targeting the NF-κB, JAK/STAT, BCL2, NOTCH, and Toll-like receptor signaling pathways; however, studies in these 2 MZL entities are yet to prove a definitive benefit. Molecular profiling is now a cornerstone of diagnostic, prognostic, and therapeutic strategies to offer patient- and disease-specific solutions. The development of a wider range of effective targeted therapies and prognostic biomarkers is keenly awaited and is expected to strongly affect the natural history of SMZL and NMZL.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2422-2422
Author(s):  
Jose A. Martinez-Climent ◽  
Cristina Robledo ◽  
Manuela Mollejo ◽  
Anton Parker ◽  
Juan L. Garcia ◽  
...  

Abstract Splenic marginal zone lymphoma (SMZL) is an indolent B cell malignancy whose diagnosis is based on lymphocyte morphology, immunophenotype and marrow and/or splenic histology. Unlike other lymphomas, there is not a common chromosomal translocation specific for SMZL, and genetic prognostic factors are poorly defined. To investigate the pattern of genomic aberrations in SMZL, we applied comparative genomic hybridization to BAC microarrays (array CGH) to a well characterized series of 75 SMZL specimens. We applied two different 1 Mb-resolution BAC arrays: UCSF HumArray 3.2 and a novel array CGH platform developed at Univ. of Salamanca. These arrays allowed us to detect DNA copy number changes across the genome with high accuracy in 67 of 75 patient samples. Data were compared with our previous array CGH studies of 170 samples from different B-cell lymphoma subgroups. FISH studies for IGH, IGK and IGL translocations and 7q deletion were performed on tissue microarrays in 24 cases. Of the 67 samples, 19 (28%) showed a normal genomic profile. The median number of genomic aberrations per tumor was 2.2 (1.3 gains and 0.9 losses), which was lower than the rates detected in other lymphoma subgroups (diffuse large cell lymphoma, 6.4; mantle cell lymphoma, 6; follicular lymphoma, 4.5) and comparable to MALT lymphomas (2 abnormalities per tumor). SMZL cells showed a genomic pattern characterized by gain of chromosomes 3q24-q29 (18%), 6p (9%), 12q (9%), and 18q (4%) and loss of 7q32 (34%), 8p21-p23 (13%), 17p13 (10%) at P53 locus and 6q21-q27 (9%). Notably, no alterations of the P16/ARF (9p21) or MYC loci (8q24) were detected. Correlation of array CGH data with conventional cytogenetics, FISH and LOH studies revealed a high concordance. Detailed mapping of 7q deletions delineated a consensus region of loss of 3 Mb in 7q32. This 7q deletion was almost exclusive to SMZL, being observed in only 5 of 170 non-SMZL B-cell lymphomas (p=0.0000001). Four cases presented IG-translocation. Mutation of IGH was observed in 62% and correlated with a complex karyotype (61 vs. 13%; p=0,0008) whereas unmutated IGH correlated with the deletion of 7q (56 vs. 23%; p=0,01). Among the various genomic abnormalities, only the deletion of 8p or the presence of a complex karyotype correlated with inferior overall survival (OS) (median OS, 58 vs. 110 months, p=0,004; and 60 vs. 105 months, p=0,01; respectively). In summary, array CGH has defined a pattern of genomic aberrations in SMZL that differs from other B-cell lymphoma subgroups and that may predict overall survival. Because the deletion of 7q32 is the most distinctive genetic marker in SMZL, the identification of a putative tumor suppressor gene inactivated within the region of deletion seems mandatory.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 5086-5086
Author(s):  
Luz Martínez-Avilés ◽  
Marta Salido ◽  
Beatriz Bellosillo ◽  
Vera Adema ◽  
Ana Ferrer ◽  
...  

Abstract Abstract 5086 Background Splenic marginal zone lymphoma (SMZL) is a rare low-grade B-cell lymphoproliferative disorder with characteristic clinical, cytological, histological and immunophenotypical features. The most common cytogenetic abnormality, present in 30–40% of the patients is the 7q deletion, that extends from 7q21 to 7q36. This aberration may represent a primary pathogenic event in SMZL. Recently, mutations in the EZH2 gene, located at 7q36.1, have been described in different hematological malignancies including B-cell lymphomas. However, the role of the EZH2 gene in SMZL has to be elucidated. Aim To determine the prevalence of EZH2 mutations in a cohort of SMZL patients. Patients and Methods Twenty-nine patients with SMZL were screened for mutations in the EZH2 gene. From the whole cohort, 11 patients presented 7q deletion (three of them as a single anomaly), 11 had a normal karyotype and 7 had other cytogenetic aberrations. The mutational analysis of the EZH2 gene was performed by direct sequencing using primers covering the whole exome of the gene. DNA was extracted from CD19 isolated B-cells from peripheral blood or from total lymphocytes if the percentage of pathologic B-cell was higher than 50%. Results From the whole cohort of 29 SMZL patients, no pathogenic mutations (frameshift or nonsense mutations) were detected in the EZH2 gene in any of the patients analyzed. Five patients harboured the missense mutation D185H in exon 6, that has been previously described as a single nucleotide polymorphism (SNP). Conclusions In conclusion, the EZH2 gene is not mutated in our series of SMZL patients suggesting that this gene is not involved in the pathogeny of this entity. Acknowledgments: Fellowship FI2008 (AGAUR) to LMA, This work was supported (in part) by grants from Instituto de Salud Carlos III FEDER; Red Temática de Investigación Cooperativa en Cáncer (RTICC, FEDER): RD06/0020/0031 and RD07/0020/2004; Ministerio de Sanidad y Consumo (Spain): PI07/0586. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2667-2667 ◽  
Author(s):  
Marzia Varettoni ◽  
Luca Arcaini ◽  
Silvia Zibellini ◽  
Emanuela Boveri ◽  
Sara Rattotti ◽  
...  

Abstract Abstract 2667 Waldenström Macroglobulinemia (WM) is a B-cell lymphoproliferative disorder characterized by bone marrow infiltration by lymphoplasmacytic lymphoma associated with a monoclonal component of IgM type in the serum. WM is often preceded by an IgM monoclonal gammopathy of undetermined significance (IgM-MGUS). The cumulative probability of progression of IgM-MGUS to WM or to other lymphoproliferative disorders is approximately 1.5% per year. Other mature B-cell neoplasms such as splenic marginal zone lymphoma (SMZL) and B-cell chronic lymphoproliferative disorders (B-CLPD) can carry an IgM monoclonal component and should therefore be considered in differential diagnosis with WM. In a study based on parallel sequencing of the whole genome of lymphoplasmacytic cells and paired normal tissue from WM patients, Treon et al (Blood. 2011;118:Abstract 300) have identified a highly recurrent somatic mutation with oncogenic activity in the myeloid differentiation primary response (MYD88) gene, leading to a change from leucine to proline at position 265 of the aminoacid sequence [MYD88 (L265P)]. Targeted Sanger resequencing showed MYD88 (L265P) in 90% of WM patients, but only in a minority of patients with IgM-MGUS or other mature B-cell neoplasms such as SMZL. We developed an allele-specific PCR for the MYD88 (L265P) mutation, and studied 58 patients with WM, 77 with IgM-MGUS, 84 with splenic marginal zone lymphoma (SMZL) and 52 with B-cell chronic lymphoproliferative disorders (B-CLPD). DNA was obtained from bone marrow cells (n=204) and peripheral blood (n=67). The aims of this study were: i) to assess the prevalence of the mutation in WM, IgM-MGUS, SMZL, and B-CLPD; ii) to analyze the relationship between MYD88 (L265P) mutation and clinical phenotype; iii) to evaluate the impact of the mutation on the risk of progression from IgM-MGUS WM or other lymphoproliferative disorders. The MYD88 (L265P) mutation was detected in 58/58 (100%) patients with WM, either asymptomatic (n=39) or symptomatic (n=18), and in 36/77 (47%) patients with IgM-MGUS. In addition, it was detected in 5/84 (6%) patients with SMZL and in 3/52 (6%) with B-CLPD; of these MYD88 (L265P)-positive subjects, 4 SMZL and 2 B-CLPD patients carried a serum IgM monoclonal component, while the remaining B-CLPD patient carried a double (IgM and IgG) monoclonal component. Compared with IgM-MGUS patients with wild-type MYD88, those carrying MYD88 (L265P) had significantly higher levels of IgM (P<.0001), lower levels of IgG (P=.04) and IgA (P=.04), and higher incidence of Bence-Jones proteinuria at diagnosis (P=.002). During the follow-up, 9 patients with IgM-MGUS progressed to WM (7 cases) or to marginal zone lymphoma (2 cases). Using a case-control approach, the risk of evolution of patients with MYD88 (L265P) was significantly higher as compared to that of patients with wild-type MYD88 sequence (OR 4.7, 95% confidence interval 0.8–48.7, P=.047). In conclusion, the findings of this study indicate that: i) the allele-specific PCR we developed is able to detect the MYD88 (L265P) mutation in all patients with WM and in nearly half the patients with IgM-MGUS, and therefore represents a useful diagnostic tool; ii) MYD88 (L265P) is an uncommon molecular lesion in SMZL and in B-CLPD, but is associated with an IgM monoclonal component in the few positive patients, suggesting that some cases of B-CLPD might be included in the spectrum of WM; iii) in IgM-MGUS, the mutation is associated with greater disease burden and higher risk of disease progression, and therefore represents a useful prognostic marker. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2698-2698
Author(s):  
Nerea Martinez ◽  
Ignacio Varela ◽  
Jose P. Vaque ◽  
Sophia Derdak ◽  
Sergi Beltran ◽  
...  

Abstract Abstract 2698 Background: Splenic marginal zone lymphoma (SMZL) is a small B cell neoplasm whose molecular pathogenesis is still unknown. It has a relatively indolent course, but a fraction of the cases may show an aggressive behavior. The lack of comprehensive molecular analysis for SMZL precludes the development of targeted therapy. Here we studied the mutational status of 6 SMZL samples using Whole Exome Next Generation Sequencing. Methods: Genomic DNA was extracted from splenic tumor or peripheral blood samples and oral mucosa as the corresponding non-tumor control. Whole exome sequencing was performed at CNAG (Barcelona, Spain) following standard protocols for high-throughput paired-end sequencing on the Illumina HiSeq2000 instruments (Illumina Inc., San Diego, CA). The variant calling was performed using an in house written software calling potential mutations showing a minimum independent multi-aligner evidence. Results: We performed paired-end-76pb whole exome sequencing on 6 SMZL samples and the corresponding normal counterpart. Three of the samples corresponded to CD19 isolated cells from peripheral blood, while other three corresponded to spleen freshly frozen tissue. The mean coverage obtained was 104.07 (82.46–119.59) with a mean of 91.41% (90.41–93.73) of bases with at least 15× coverage. After filtering, 237 substitutions and 21 indels where obtained. No recurrent variation was found. Six of the variations found here were already described in other malignancies. Variations were classified into silent (75), missense (147), nonsense (8), and essential splice (5), according to their potential functional effect, and into tolerated (54) and deleterious (76) according to the “variant effect predictor” tool of Ensembl Genome Browser. Whole exome sequencing permitted us to identify variations in several genes of TLR/NFkB pathway (Myd88, Peli3), BCR (Myd88, Arid3A) or signal transduction (ARHGAP32), essential pathways for B-cell differentiation. These variations and other involving selected genes, such as the Bcl6 repressor BCOR, were validated by capillary sequencing. These results were confirmed and expanded in a second series of 10 new cases by exome sequencing. Conclusions: SMZL samples contain somatic mutation involving genes regulating BCR signaling, TLR/NFKB pathways and chromatin remodeling. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2397-2397
Author(s):  
Gabriel Brisou ◽  
Laurent Jallades ◽  
Alexandra Traverse-Glehen ◽  
Francoise Berger ◽  
Aurélie Verney ◽  
...  

Abstract Abstract 2397 B cells can undergo at least two differentiation pathways, dependent of T cells or not, starting from follicular or marginal zone B cells respectively. The T-independent response, less understood than the germinal center reaction, is triggered by specific antigens and arises from marginal zone B cells. During this development, some B cells undergo somatic hypermutation (SHM) and class switch recombination (CSR), triggered by the same DNA editing enzyme called Activation Induced Cytidine Deaminase (AID). The splenic marginal zone lymphoma (SMZL) is a rare lymphoproliferative disorder characterized by a clonal expansion of B cells in the marginal zone of the spleen. These B-cells underwent SHM in roughly 60% of the cases but nearly none underwent CSR. These observations suggest that tumor clones originate from a particular activated B cell subset not transiting through the germinal center. In order to confirm this hypothesis, we focused our work on the status and impact of AID in this disease and worked on purified B cells extracted from spleen of well-characterized SMZL cases. We determined AID status by quantitative RT-PCR analysis on 27 SMZL samples and compared it with 5 controls. In the SMZL group the relative level of expression of AID is heterogeneous but two subgroups could be distinguished: one considered as expressing AID (14 cases out of the 27 analyzed), the remaining considered as not expressing AID. When we compared AID expression rate with occurrence of SHM and CSR, no clear correlation between AID expression and presence of SHM or CSR could be observed suggesting that AID, when expressed, is dysfunctional. To address this hypothesis, we first analyzed AID protein by immunohistochemistry and a good correlation between IHC signal and AID mRNA expression level has been observed. As AID gene was not mutated, we next focused our work on AID mRNA splicing variants as these variants exhibit different functions according to the domain of the protein they contain in a murine model. We found that SMZL B cells express various splicing variants of AID mRNA, some of those variants corresponding to the full length isoform (n = 6/17), and other variants corresponding to AID-ΔE4a (n = 2/17) or AID-ΔE4 (n = 7/17) isoforms known to be expressed in normal germinal center B cells as well as in Chronic Lymphocytic and Acute Lymphoblastic Leukemia. These findings indicate that although expressed at the mRNA and protein levels, AID may not be fully functional in SMZL cases. Finally we addressed the potential clinical significance of AID expression. We identified for that purpose a group of “progressive SMZL” patients that had received immuno-chemotherapy after splenectomy because of a significant risk of progression or transformation into aggressive large B cell lymphoma (n = 8/27) pre-empting outcome differences. We found a higher proportion of AID expressing patients in the defined “progressive SMZL” group (n = 7/8) as compared to the proportion found in the “indolent SMZL” group (n = 5/14, p = 0,03). Altogether, this data suggest that the B cell clone leading to SMZL originate from the marginal zone and support the hypothesis of a lymphoproliferative disorder affecting the T-independent response. AID expression in SMZL may reflect an advanced stage of the disease and could be correlated with the evolution of the lymphoma into a more clinically or pathologically aggressive form. Disclosures: No relevant conflicts of interest to declare.


2005 ◽  
Vol 156 (2) ◽  
pp. 122-128 ◽  
Author(s):  
Claus L. Andersen ◽  
Alicja Gruszka-Westwood ◽  
Shayne Atkinson ◽  
Estella Matutes ◽  
Daniel Catovsky ◽  
...  

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S106-S107
Author(s):  
Xiaohong Zhang

Abstract Extranodal marginal zone lymphoma (EMZL) is a low-grade B-cell lymphoma representing about the third most common non-Hodgkin lymphoma in the Western world. EMZL shows heterogeneous morphological features and expresses no specific immunohistochemical markers except B-cell markers. BCL10 and MALT mutations causing NF-kB pathway activation play an important role in oncogenesis of EMZL. Aberrant nuclear expression of BCL10 is reported in some EMZLs. Nuclear expression of BCL10 has not been well compared between EMZL and other small B-cell lymphomas. The aim of this study is to evaluate the expression of BCL10 and three markers in different small B-cell lymphomas. Tissue microarray blocks and selected tissue blocks, formalin fixed and paraffin embedded, were selected for immunohistochemical (IHC) studies. More than 100 cases of different small B-cell lymphomas include EMZL, small lymphocytic lymphoma (SLL), mantle cell lymphoma (MCL), follicular lymphoma (FL), lymphoplasmacytic lymphoma (LPL), and hairy cell leukemia (HCL) in the bone marrow biopsy. Commercially available antibodies from DAKO for BCL-10, IRTA-1, LEF-1, and SOX-11 were used according to the protocol. Immunoreactivity in greater than 20% of the tumor cells was considered positive. BCL-10 nuclear expression occurred mostly in EMZL but also in other small B-cell lymphomas except LPL and HCL. Cytoplasmic expression of IRTA-1 was detected in all cases of EMZL and also in SLL, MCL, and FL cases; it was negative in LPL and HCL. Nuclear expression of LEF-1 was detected mostly in SLL cases, a few cases of MZL, and none of the cases of MCL, FL, LPL, and HCL. Nuclear staining of SOX11 was found in most MCL cases; it was negative in all cases of SLL, EMZL, FL, LPL, and HCL. The IHC markers of BCL-10, IRTA-1, LEF-1, and SOX11 increase our ability to make accurate diagnosis of small B-cell lymphomas.


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