Identification of MNDA as a new marker for nodal marginal zone lymphoma

MNDA expression and its value in differential diagnosis of B-cell non-Hodgkin lymphomas: a comprehensive analysis of a large series of 1293 cases

AIMS

MNDA (myeloid nuclear differentiation antigen) has been considered as a potential diagnostic marker for marginal zone lymphoma (MZL), but its utility in distinguishing MZL from other B-cell non-Hodgkin lymphomas (B-NHLs) and its clinicopathologic relevance in diffuse large B-cell lymphoma (DLBCL) are ambiguous. We comprehensively investigated MNDA expression in a large series of B-NHLs and evaluated its diagnostic value.

METHODS

MNDA expression in a cohort of 1293 cases of B-NHLs and 338  cases of reactive lymphoid hyperplasia (RLH) was determined using immunohistochemistry and compared among different types of B-NHL. The clinicopathologic relevance of MNDA in DLBCL was investigated.

RESULTS

MNDA was highly expressed in MZLs (437/663, 65.9%), compared with the confined staining in marginal zone B-cells in RLH; whereas neoplastic cells with plasmacytic differentiation lost MNDA expression. MNDA expression was significantly higher in mantle cell lymphoma (MCL, 79.6%, p = 0.006), whereas lower in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL, 44.8%, p = 0.001) and lymphoplasmacytic lymphoma (LPL, 25%, p = 0.016), and dramatically lower in follicular lymphoma (FL, 5.2%, p < 0.001), compared with MZL. 29.6% (63/213) of DLBCLs were positive for MNDA. The cases in non-GCB group exhibited a higher rate of MNDA positivity (39.8%) compared to those in GCB group (16.3%) (p < 0.001), and MNDA staining was more frequently observed in DLBCLs with BCL2/MYC double-expression (50%) than those without BCL2/MYC double-expression (24.8%) (p = 0.001). Furthermore, there was a significant correlation between MNDA and CD5 expression in DLBCL (p = 0.036).

CONCLUSIONS

MNDA was highly expressed in MZL with a potential utility in differential diagnosis between MZL and RLH as well as FL, whereas its value in distinguishing MZL from MCL, CLL/SLL is limited. In addition, MNDA expression in DLBCL was more frequently seen in the non-GCB group and the BCL2/MYC double-expression group, and demonstrated a correlation with CD5, which deserves further investigation. The clinical relevance of MNDA and its correlation with the prognosis of these lymphomas also warrant to be fully elucidated.

MNDA, a PYHIN factor involved in transcriptional regulation and apoptosis control in leukocytes

Inflammation control is critical during the innate immune response. Such response is triggered by the detection of molecules originating from pathogens or damaged host cells by pattern-recognition receptors (PRRs). PRRs subsequently initiate intra-cellular signalling through different pathways, resulting in i) the production of inflammatory cytokines, including type I interferon (IFN), and ii) the initiation of a cascade of events that promote both immediate host responses as well as adaptive immune responses. All human PYRIN and HIN-200 domains (PYHIN) protein family members were initially proposed to be PRRs, although this view has been challenged by reports that revealed their impact on other cellular mechanisms. Of relevance here, the human PYHIN factor myeloid nuclear differentiation antigen (MNDA) has recently been shown to directly control the transcription of genes encoding factors that regulate programmed cell death and inflammation. While MNDA is mainly found in the nucleus of leukocytes of both myeloid (neutrophils and monocytes) and lymphoid (B-cell) origin, its subcellular localization has been shown to be modulated in response to genotoxic agents that induce apoptosis and by bacterial constituents, mediators of inflammation. Prior studies have noted the importance of MNDA as a marker for certain forms of lymphoma, and as a clinical prognostic factor for hematopoietic diseases characterized by defective regulation of apoptosis. Abnormal expression of MNDA has also been associated with altered levels of cytokines and other inflammatory mediators. Refining our comprehension of the regulatory mechanisms governing the expression of MNDA and other PYHIN proteins, as well as enhancing our definition of their molecular functions, could significantly influence the management and treatment strategies of numerous human diseases. Here, we review the current state of knowledge regarding PYHIN proteins and their role in innate and adaptive immune responses. Emphasis will be placed on the regulation, function, and relevance of MNDA expression in the control of gene transcription and RNA stability during cell death and inflammation.

Leukemic-phase mucosa-associated lymphoid tissue lymphoma

A 78-year-old man presenting with leukocytosis was admitted to our hospital. The patient was asymptomatic and showed no lymphadenopathy. Peripheral blood flow cytometry revealed a leukemic-phase B-cell lymphoma with medium-to-large abnormal cells with reticulum. Positron emission tomography/computed tomography revealed abnormal uptake in the right orbit, bone marrow, and spleen. We performed immunological staining and fluorescence in situ hybridization on tissues extracted from the right orbit and bone marrow, which led to the diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma. Polymerase chain reaction analysis of immunoglobulin heavy chain rearrangements in the right orbital mass and bone marrow suggested that they were identical clones. Based on these collective findings, the diagnosis of leukemic-phase MALT lymphoma was confirmed, with sites of involvement including the bone marrow, peripheral blood, right orbit, and spleen. This is a highly rare case of leukemic MALT lymphoma.

The many faces of nodal and splenic marginal zone lymphomas. A report of the 2022 EA4HP/SH lymphoma workshop

Session 3 of the lymphoma workshop of the XXI joint meeting of the European Association for Haematopathology and the Society for Hematopathology took place in Florence, Italy, on September 22, 2022. The topics of this session were splenic and nodal marginal zone lymphomas, transformation in marginal zone lymphomas, and pediatric nodal marginal zone lymphomas and their differential diagnosis as well as related entities. Forty-two cases in these categories were submitted to the workshop, including splenic lymphomas (marginal zone and diffuse red pulp lymphomas), transformed marginal zone lymphomas (splenic and nodal), nodal marginal zone lymphomas with increased TFH-cells, and pediatric nodal marginal zone lymphomas. The case review highlighted some of the principal problems in the diagnosis of marginal zone lymphomas, including the difficulties in the distinction between splenic marginal zone lymphoma, splenic diffuse red pulp lymphoma, and hairy cell leukemia variant/splenic B-cell lymphoma with prominent nucleoli which requires integration of clinical features, immunophenotype, and morphology in blood, bone marrow, and spleen; cases of marginal zone lymphoma with markedly increased TFH-cells, simulating a T-cell lymphoma, where molecular studies (clonality and mutation detection) can help to establish the final diagnosis; the criteria for transformation of marginal zone lymphomas, which are still unclear and might require the integration of morphological and molecular data; the concept of an overlapping spectrum between pediatric nodal marginal zone lymphoma and pediatric-type follicular lymphoma; and the distinction between pediatric nodal marginal zone lymphoma and "atypical" marginal zone hyperplasia, where molecular studies are mandatory to correctly classify cases.

Eosinophil-rich variant of nodal marginal zone lymphoma: a clinicopathological study of 11 cases

AIMS

Tissue eosinophilia is commonly observed in T-cell and classic Hodgkin lymphomas, but rarely in B-cell lymphomas. Herein, we present the first report of a case series on nodal marginal zone lymphoma (NMZL) with tissue eosinophilia.

METHODS AND RESULTS

All 11 patients in this study had nodal disease at primary presentation. The mean age at diagnosis was 64 years. The mean follow-up period was 39 months, and all patients were alive. Nine of the 11 patients (82%) showed no recurrence, but the other two patients experienced recurrence in the lymph nodes or skin. Marked eosinophilic infiltration was observed in all biopsied lymph nodes. Nine of the 11 patients had a preserved nodular architecture with expanded interfollicular areas. The other two patients showed diffuse lymphoma cell infiltration with effacement of nodal architecture. One of them was diagnosed as having diffuse large B-cell lymphoma transformed from NMZL because large cells accounted for >50% of the lymphoma cells and formed sheet-like patterns. Cells were positive for CD20 and BCL2 and negative for CD5, CD10, and BCL6. Some patients showed myeloid cell nuclear differentiation antigen (MNDA) positivity. All patients showed B-cell monoclonality via flow cytometry, southern blotting, and/or polymerase chain reaction (PCR).

CONCLUSION

All patients showed distinctive morphological features and could be misdiagnosed with peripheral T-cell lymphoma due to their eosinophil-rich backgrounds. The predominance of B cells, absence of histiocytes, and high endothelial venules in the interfollicular areas are key factors for diagnosis. B-cell monoclonality is the most reliable evidence of differentiation. We designated this type of lymphoma as an eosinophil-rich variant of NMZL.

Study of the Utility of Myeloid Cell Nuclear Differentiation Antigen (MNDA) in the Diagnosis of Marginal Zone Lymphoma

Myeloid cell nuclear differentiation antigen (MNDA) is normally expressed on myelomonocytic cells and a subset of B lymphocytes. It was found to be differentially expressed between nodal marginal zone lymphoma (MZL) and follicular lymphoma (FL). However, MNDA has not been widely used as a diagnostic marker in clinical practice. To validate its utility, we studied the expression of MNDA by immunohistochemistry in 313 cases of small B-cell lymphomas. Our results showed that MNDA was positive in 77.9% of MZL, 21.9% of mantle cell lymphoma, 28.9% of small lymphocytic lymphoma/chronic lymphocytic leukemia, 2.6% of FL, and 25% of lymphoplasmacytic lymphoma. MNDA positivity varied from 68.0% to 84.0% among the 3 MZL subtypes, with extranodal MZL having the highest percentage. There was a statistically significant difference in MNDA expression between MZL and FL, mantle cell lymphoma, small lymphocytic lymphoma/chronic lymphocytic leukemia, or lymphoplasmacytic lymphoma. CD43 expression was slightly more frequent in MNDA-negative MZL than in MNDA-positive MZL. Combined use of CD43 and MNDA improved the diagnostic sensitivity for MZL from 77.9% to 87.8%. There was a trend of positive correlation between MNDA and p53 in MZL. In conclusion, MNDA is preferentially expressed in MZL among small B-cell lymphomas and it is a useful marker for the differentiation of MZL and FL.

Follicular lymphoma and marginal zone lymphoma: how many diseases?

Follicular lymphoma (FL) and marginal zone lymphoma (MZL) are indolent mature B-cell neoplasms with variable clinical presentation and distinct histopathologic features. Recent advances in the biology and molecular characteristics of these lymphomas have further expanded our understanding of the heterogeneous nature of these lymphomas, with increasing recognition of specific disease entities within the broader categories of FL and MZL. Here, we discuss the conclusions of the 2022 International Consensus Classification of Mature Lymphoid Neoplasms (2022 ICC) dealing with FL, and review differences with the proposed WHO 5th Edition classification. We review issues related to grading and alternative forms of FL especially those lacking the genetic hallmark of FL, the t(14;18) chromosomal alteration. Among them, t(14;18)-negative CD23⁺ follicle center lymphoma has been proposed by the 2022 ICC as a provisional entity. Other follicle center-derived lymphomas such as pediatric-type follicular lymphoma, testicular follicular lymphoma, primary cutaneous follicle center lymphoma, and large B-cell lymphoma with IRF4 rearrangement are considered distinct entities separate from conventional FL. Importantly, large B-cell lymphoma with IRF4 rearrangement introduced as a provisional entity in the WHO 2017 is upgraded to a definite entity in the 2022 ICC. We also discuss diagnostic strategies for recognition of MZLs including splenic MZL, extranodal MZL (MALT lymphoma), and primary nodal MZL. The importance of molecular studies in the distinction among marginal zone lymphoma subtypes is emphasized, as well as their value in the differential diagnosis with other B-cell lymphomas.

Immunohistochemistry for IRTA1 and MNDA helps differentiate gastric MALT lymphoma from chronic gastritis/reactive lymphocyte hyperplasia

It is difficult to histologically differentiate extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) from chronic gastritis (CG)/ reactive lymphoid hyperplasia (RLH). To determine whether immunohistochemistry for IRTA1 and MNDA can differentiate gastric MALT lymphoma from CG/RLH, we investigated 81 stomach biopsy specimens [Wotherspoon grade (WG) 1, 11 cases; WG 2, 9 cases; WG 3, 20 cases; WG 4, 31 cases; and WG 5, 10 cases]. According to a previously reported algorithm involving PCR for immunoglobulin heavy (IgH) chain locus rearrangement, all 81 cases were divided into three groups: CG/RLH (55 cases), MALT lymphoma (19 cases) groups, and IgH undetectable group (7 cases). We analyzed the CG/RLH and MALT lymphoma groups. The median percentage of IRTA1-positive cells was 0% (range 0%-90.6%) in the CG/RLH group and 43.5% (range 0%-97.6%) in the MALT lymphoma group (p < 0.0001). The median percentage of MNDA-positive cells was 32.4% (range 0%-97.6%) in the CG/RLH group and 55.1% (range 0%-97.6%) in the MALT lymphoma group (p = 0.0044). These results indicate that immunohistochemistry for IRTA1 and MNDA can help differentiate gastric MALT lymphoma from CG/RLH.

Extranodal MALT Lymphoma in the Oral Cavity: A Series of Three Cases with Review of Literature

BACKGROUND

Diagnosis of MALT lymphoma in the oral cavity is challenging. There is a great overlap in the histopathologic, immuno-histochemical and molecular features of MALT lymphoma with reactive lymphoid proliferations. The literature shows a very few case reports of primary MALT lymphoma of oral cavity.

METHODS

We discuss the histopathologic, immuno-histochemical, cytogenetic features, treatment and behavior of 3 cases of primary MALT lymphoma oral cavity along with review of literature.

RESULTS

The age ranged from 40 to 57 years (male to female ratio = 2:1). The sites involved were hard palate, bilateral gingivobuccal sulcus and right buccal mucosa. The most common histology was centrocyte-like (2 cases). Lymphoepithelial lesions were absent. On immunohistochemistry, all tumors showed diffuse strong CD20 and bcl2 expression with strong and diffuse MNDA staining in one case. IgH; MALT1 translocation was not seen in any of these cases. One patient received local radiotherapy, one received steroids; while the case 3 received RCHOP (Rituximab, cyclophosphamide, hydroxydaunorubicin hydrochloride, vincristine and prednisone) chemotherapy. Two patients had complete remission while one had recurrence.

CONCLUSION

MALT lymphoma of oral cavity shows a wide spectrum of morphology with presence of transformed cells, that may lead to misdiagnosis of DLBL. Treatment guidelines are not well established but a tendency to excise MALT lymphomas of oral cavity has been observed. Nevertheless, MALT lymphoma of oral cavity appears to be an indolent disease.

Myeloid Nuclear Differentiation Antigen (MNDA): an aid in differentiating lymphoplasmayctic lymphoma and splenic marginal zone lymphoma in bone marrow biopsies at presentation

The differential diagnosis between lymphoplasmacytic lymphoma (LPL) and marginal zone B-cell lymphoma, particularly splenic type (SMZL) can be challenging on onset bone marrow biopsy (BMB) since morphology and phenotype are not specific and clinical features can overlap or be mildly developed at diagnosis. The LPL-specific L265P mutation in the MYD88 gene is not available in all laboratories and genetic aberrancies identified in SMZL (del7q, mutations of NOTCH2 and KLF2) are seldom searched in routine practice. The study aim is to investigate the potential role of MNDA expression in this specific differential diagnosis. We report MNDA reactivity in 559 small B-cell lymphoma (SBCL) patients including bone marrow biopsies from 90 LPL and 91 SMZL. MYD88 p.Leu265Pro mutation status was assessed and confirmed as positive in 24 of 90 LPL cases, which served as the test set. MNDA staining was negative in 23/24 LPL cases in the test set (96%). In the 157 remaining cases (66 LPL, 91 SMZL), which served as validation set, the MYD88 p.Leu265Pro mutation was unavailable and MNDA was more frequently expressed in SMZL (p<0.00001). In addition, immunohistochemical features more consistent with SMZL (i.e. presence of CD23+ follicular dendritic cell meshworks, polytypic plasma cells, DBA44 reactivity) were more often present in MNDA positive cases (statistically significant for 2 such parameters). On the widest case-series so far published focusing on LPL and SMZL immunohistochemical diagnosis at onset on BMB, we demonstrated that MNDA expression significantly support the diagnosis of SMZL. This observation may be of particular help in cases where the MYD88 p.Leu265Pro mutational status and/or SMZL-related genetic aberrations are unavailable.

The Relevance of Additional Immunohistochemical Markers on the Differential Diagnosis of Small B-Cell Lymphomas: A Case-control Study

Objective:

Clinical and pathological differential diagnosis of small B-cell lymphomas (SBCLs) is still controversial and may be difficult due to their overlapping morphology, phenotype, and differentiation to plasma cells. We aimed to examine the expression of the immune receptor translocation-associated protein 1 (IRTA1), myeloid cell nuclear differentiation antigen (MNDA), lymphoid enhancer-binding factor-1 (LEF1), and stathmin 1 (STMN1) markers in SBCL cases involving different sites that may have plasma cell differentiation.

Materials and Methods:

We studied 154 tissue samples with lymphoma involvement from 116 patients and evaluated the staining distribution of the markers. Expressions were evaluated in 21 chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), 7 follicular lymphoma (FL), 14 nodal marginal zone lymphoma, 17 extranodal marginal zone lymphoma, 55 splenic marginal zone lymphoma, 22 marginal zone lymphoma-not otherwise specified, and 18 lymphoplasmacytic lymphoma/Waldenström macroglobulinemia cases by immunohistochemistry.

Results:

The results confirmed that LEF1 was the most sensitive and specific marker for CLL/SLL and STMN1 was the most sensitive and specific marker for FL (p<0.001). MNDA and IRTA1 were useful markers to distinguish marginal zone lymphomas.

Conclusion:

Our results suggest that LEF1 for CLL/SLL and STMN1 for FL are reliable markers. LEF1, MNDA, STMN1, and IRTA1 are helpful with other routinely used immunohistochemical markers in a diagnostic algorithm considering their limitations.

IRTA1 positivity helps identify a MALT-lymphoma-like subset of primary cutaneous marginal zone lymphomas, largely but not exclusively defined by IgM expression

BACKGROUND

It has been proposed that primary cutaneous marginal zone lymphomas (PCMZLs) include a MALT-lymphoma-like IgM+ subset and a class-switched subset, which is unlike most other MALT lymphomas. Whether expression of the MALT lymphoma-associated biomarkers IRTA1 and MNDA would support this concept and whether they might help explain why some patients have both subtypes is uncertain.

METHODS

Twenty-five PCMZLs from 21 patients were stained for IRTA1 by in situ hybridization and for MNDA by immunohistochemistry. In two patients, polymerase chain reaction (PCR)-based B-cell clonality studies were performed on biopsy specimens of metachronous lesions, which expressed different heavy chains. All results were correlated with the histopathologic and clinical findings.

RESULTS

Five of six IgM+ PCMZLs were IRTA1+ vs three of 18 evaluable class-switched cases (P = 0.0069). Two of the class-switched IRTA1+ cases were in patients with clonally-related IRTA1+ IgM+ PCMZLs. IRTA1 positivity showed a statistically significant correlation with several MALT-lymphoma-associated histopathologic findings. In contrast, all PCMZL cases showed at least some MNDA expression with no differences between IgM+ and class-switched cases.

CONCLUSIONS

IRTA1 identifies MALT-lymphoma-like PCMZLs that are largely but not exclusively IgM+. This supports the concept of two PCMZL subsets but suggests their distinction should not be based solely on their heavy chain expression.

Altered Spectrum of Lymphoid Neoplasms in a Single-Center Cohort of Common Variable Immunodeficiency with Immune Dysregulation

Purpose

Common variable immune deficiency (CVID) confers an increased risk of lymphoid neoplasms, but reports describing the precise WHO specification of the lymphoma subtypes and their immunological environment are lacking. We therefore classified lymphomas—occurring in a cohort of 21 adult CVID patients during a 17-year period at our center—according to the 2016 WHO classification and characterized the local and systemic immunological context

Results

The median time between the onset of CVID and lymphoma was 14 years. Patients showed a high prevalence of preceding immune dysregulation: lymphadenopathy (n = 13, 62%), splenomegaly (n = 18, 86%), autoimmune cytopenia (n = 14, 67%), and gastrointestinal involvement (n = 15, 71%). The entities comprised extranodal marginal zone lymphoma (n = 6), diffuse large B cell lymphoma (n = 7), plasmablastic lymphoma (n = 1), classic Hodgkin lymphoma (n = 4, including three cases with germline CTLA4 mutations), T cell large granular lymphocytic leukemia (n = 2), and peripheral T cell lymphoma, not otherwise specified (n = 1), but no follicular lymphoma. An Epstein-Barr virus association was documented in eight of 16 investigated lymphomas. High expression of PDL1 by tumor cells in five and of PDL1 and PD1 by tumor-infiltrating macrophages and T cells in 12 of 12 investigated lymphomas suggested a tolerogenic immunological tumor environment.

Conclusion

In summary, a diverse combination of specific factors like genetic background, chronic immune activation, viral trigger, and impaired immune surveillance contributes to the observed spectrum of lymphomas in CVID. In the future, targeted therapies, e.g., PD1/PDL1 inhibitors in CVID associated lymphomas with a tolerogenic environment may improve therapy outcome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10875-021-01016-4.

The Pathogenic Effects of Fusobacterium nucleatum on the Proliferation, Osteogenic Differentiation, and Transcriptome of Osteoblasts

As one of the most common oral diseases, periodontitis is closely correlated with tooth loss in middle-aged and elderly people. Fusobacterium nucleatum (F. nucleatum) contributes to periodontitis, but the evidence in alveolar bone loss is still unclear. In this study, cytological experiments and transcriptome analyses were performed to characterize the biological process abnormalities and the molecular changes of F. nucleatum-stimulated osteoblasts. F. nucleatum could inhibit cell proliferation, promote cell apoptosis, and elevate pro-inflammatory cytokine production of osteoblasts, and it also inhibited osteoblast differentiation and mineralized nodule formation and decreased the expression of osteogenetic genes and proteins. Whole-transcriptome analyses identified a total of 235 transcripts that were differentially expressed in all six time points, most of which were inflammation-related genes. The genes, Ccl2, Ccl20, Csf1, Cx3cl1, Cxcl1, Cxcl3, Il6, Birc3, Map3k8, Nos2, Nfkb2, Tnfrsf1b, and Vcam1, played core roles in a PPI network, and interacted closely with other ones in the infection. In addition, 133 osteogenesis-related differential expression genes (DEGs) were time-serially dynamically changed in a short time-series expression miner (STEM) analysis, which were enriched in multiple cancer-related pathways. The core dynamic DEGs (Mnda, Cyp1b1, Comp, Phex, Mmp3, Tnfrsf1b, Fbln5, and Nfkb2) had been reported to be closely related to the development and metastasis in tumor and cancer progress. This study is the first to evaluate the long-term interaction of F. nucleatum on osteoblasts, which might increase the risk of cell carcinogenesis of normal osteoblasts, and provides new insight into the pathogenesis of bacterial-induced bone destruction.

MNDA controls the expression of MCL-1 and BCL-2 in chronic lymphocytic leukemia cells

The myeloid nuclear differentiation antigen (MNDA) is a stress-induced protein that promotes degradation of the anti-apoptotic factor MCL-1 and apoptosis in myeloid cells. MNDA is also expressed in normal lymphoid cells and in B-cell clones isolated from individuals with chronic lymphocytic leukemia (CLL), a disease characterized by abnormal apoptosis control. We found that MNDA expression levels inversely correlate with the amount of the anti-apoptotic proteins MCL-1 and BCL-2 in human CLL samples. We report that in response to chemotherapeutic agents that induce genotoxic stress, MNDA exits its typical nucleolar localization and accumulates in the nucleoplasm of CLL and lymphoid cells. Then, MNDA binds chromatin at Mcl1 and Bcl2 genes and affects the transcriptional competence of RNA polymerase II. Our data also reveal that MNDA specifically associates with Mcl1 and Bcl2 (pre-) mRNAs and favors their rapid turnover as a prompt response to genotoxic stress. We propose that this rapid dynamic tuning of RNA levels, which leads to the destabilization of Mcl1 and Bcl2 transcripts, represents a post-transcriptional mechanism of apoptosis control in CLL cells. These results provide an explanation of previous clinical data and corroborate the finding that higher MNDA expression levels in CLL are associated with a better clinical course.

DNA Methylation-Derived Immune Cell Profiles, CpG Markers of Inflammation, and Pancreatic Cancer Risk

BACKGROUND

Pancreatic cancer is projected to become the second most common cause of cancer-related death over the next 5 years. Because inflammation is thought to be a common trajectory for disease initiation, we sought to prospectively characterize immune profiles using DNA methylation markers and examine DNA methylation levels previously linked to inflammation biomarkers to evaluate whether these immune markers play a key role in pancreatic cancer.

METHODS

In a nested case-control study pooling three U.S. prospective cohort studies, DNA methylation was measured in prediagnostic leukocytes of incident pancreatic cancer cases and matched controls using the Illumina MethylationEPIC array. Differentially methylated regions were used to predict immune cell types, and CpGs previously associated with inflammatory biomarkers were selected for the analysis. DNA methylation data from a retrospective case-control study conducted in Spain (PanGenEU) was used for independent replication.

RESULTS

Immune cell proportions and ratio of cell proportions were not associated with pancreatic cancer risk in the nested case-control study. Methylation extent of CpGs residing in or near gene MNDA was significantly associated with pancreatic cancer risk in the nested case-control study and replicated in PanGenEU. Methylation level of a promoter CpG of gene PIM-1 was associated with survival in both studies.

CONCLUSIONS

Using a targeted approach, we identified several CpGs that may play a role in pancreatic carcinogenesis in two large, independent studies with distinct study designs.

IMPACT

These findings could provide insight into critical pathways that may help identify new markers of early disease and survival.

High-mobility group box (TOX) antibody a useful tool for the identification of B and T cell subpopulations

Thymocyte selection-associated high-mobility group box (TOX) is a DNA-binding factor that is able to regulate transcription by modifying local chromatin structure and modulating the formation of multi-protein complexes. TOX has multiple roles in the development of the adaptive immune system including development of CD4 T cells, NK cells and lymph node organogenesis. However very few antibodies recognizing this molecule have been reported and no extensive study of the expression of TOX in reactive and neoplastic lymphoid tissue has been performed to date. In the present study, we have investigated TOX expression in normal and neoplastic lymphoid tissues using a novel rat monoclonal antibody that recognizes its target molecule in paraffin-embedded tissue sections. A large series of normal tissues and B- and T-cell lymphomas was studied, using whole sections and tissue microarrays. We found that the majority of precursor B/T lymphoblastic, follicular and diffuse large B-cell lymphomas, nodular lymphocyte-predominant Hodgkin lymphomas and angioimmunoblastic T-cell lymphomas strongly expressed the TOX protein. Burkitt and mantle cell lymphomas showed TOX expression in a small percentage of cases. TOX was not found in the majority of chronic lymphocytic leukemia, myelomas, marginal zone lymphomas and classical Hodgkin lymphomas. In conclusion, we describe for the first time the expression of TOX in normal and neoplastic lymphoid tissues. The co-expression of TOX and PD-1 identified in normal and neoplastic T cells is consistent with recent studies identifying TOX as a critical regulator of T-cell exhaustion and a potential immunotherapy target. Its differential expression may be of diagnostic relevance in the differential diagnosis of follicular lymphoma, the identification of the phenotype of diffuse large B-cell lymphoma and the recognition of peripheral T-cell lymphoma with a follicular helper T phenotype.

Genome-wide promoter methylation of hairy cell leukemia

Classic hairy cell leukemia (HCL) is a tumor of mature clonal B cells with unique genetic, morphologic, and phenotypic features. DNA methylation profiling has provided a new tier of investigation to gain insight into the origin and behavior of B-cell malignancies; however, the methylation profile of HCL has not been specifically investigated. DNA methylation profiling was analyzed with the Infinium HumanMethylation27 array in 41 mature B-cell tumors, including 11 HCL, 7 splenic marginal zone lymphomas (SMZLs), and chronic lymphocytic leukemia with an unmutated (n = 7) or mutated (n = 6) immunoglobulin gene heavy chain variable (IGHV) region or using IGHV3-21 (n = 10). Methylation profiles of nontumor B-cell subsets and gene expression profiling data were obtained from public databases. HCL had a methylation signature distinct from each B-cell tumor entity, including the closest entity, SMZL. Comparison with normal B-cell subsets revealed the strongest similarity with postgerminal center (GC) B cells and a clear separation from pre-GC and GC cellular programs. Comparison of the integrated analysis with post-GC B cells revealed significant hypomethylation and overexpression of BCR-TLR-NF-κB and BRAF-MAPK signaling pathways and cell adhesion, as well as hypermethylation and underexpression of cell-differentiation markers and methylated genes in cancer, suggesting regulation of the transformed hairy cells through specific components of the B-cell receptor and the BRAF signaling pathways. Our data identify a specific methylation profile of HCL, which may help to distinguish it from other mature B-cell tumors.

Marginal zone B-cell lymphoma: lessons from Western and Eastern diagnostic approaches

Marginal zone B-cell lymphomas (MZLs) are a group of clinically indolent B-cell lymphomas postulated to derive from memory B lymphocytes in the 'marginal zone' of secondary lymphoid tissue. Today, MZL is recognised as a nosological umbrella term encompassing distinct entities with some shared phenotypic and genotypic features, including extranodal marginal zone B-cell lymphoma (EMZL) or mucosa-associated lymphoid tissue (MALT) lymphoma, splenic MZL, and nodal MZL, accounting for approximately 70%, 20%, and 10% of MZLs, respectively. These lymphomas share some phenotypic and genotypic features and have some variants and related provisional diseases, but are different in regards to their clinical and molecular characteristics. In addition, they are frequently associated with chronic antigenic stimulation represented either by infectious agents, particularly bacteria and viruses, or autoimmune diseases as exemplified by Sjögren syndrome, Hashimoto thyroiditis, and newly recognised IgG4-related disease. Furthermore, several chromosomal translocations have been identified in EMZL. In this review, we will focus on the updated histopathological criteria and the main problems with differential diagnoses in order to aid the diagnostic approach in our routine practice.

IRTA1 and MNDA Expression in Marginal Zone Lymphoma: Utility in Differential Diagnosis and Implications for Classification

Objectives

To evaluate the clinical utility of immune receptor translocation-associated protein 1 (IRTA1) and myeloid nuclear differentiation antigen (MNDA) expression in the diagnosis and classification of marginal zone lymphomas (MZLs).

Methods

IRTA1 was examined using a novel RNA in situ hybridization assay and MNDA expression determined by immunohistochemistry in 127 small B-cell neoplasms, including 80 cases of MZL.

Results

IRTA1 expression was detected in 31 (42%) of 74 MZLs vs one (2%) of 43 other small B-cell neoplasms (P < .001). MNDA staining was positive in 51 (64%) of 79 MZLs vs 21 (45%) of 46 non-MZLs (P = .06). MNDA expression was particularly uncommon in follicular lymphoma (3/14, 21%; P = .003 vs MZL). There was no association between MNDA and IRTA1 expression and the presence of monocytoid cytology. IRTA1 expression was less frequent in cases with a diffuse growth pattern.

Conclusions

IRTA1 and MNDA are useful markers in the differential diagnosis of MZLs.

Biomarker Identification for Cancer Disease Using Biclustering Approach: An Empirical Study

This paper presents an exhaustive empirical study to identify biomarkers using two approaches: frequency-based and network-based, over seventeen different biclustering algorithms and six different cancer expression datasets. To systematically analyze the biclustering algorithms, we perform enrichment analysis, subtype identification and biomarker identification. Biclustering algorithms such as C&C, SAMBA and Plaid are useful to detect biomarkers by both approaches for all datasets except prostate cancer. We detect a total of 102 gene biomarkers using frequency-based method out of which 19 are for blood cancer, 36 for lung cancer, 25 for colon cancer, 13 for multi-tissue cancer and 9 for prostate cancer. Using the network-based approach we detect a total of 41 gene biomarkers of which 15 are from blood cancer, 12 from lung cancer, 6 from colon cancer, 7 from multi-tissue cancer and 1 from prostate cancer dataset. We further extend our network analysis over some biclusters and detect some gene biomarkers not detected earlier by both frequency-based or network-based approach. We expand our work on breast cancer miRNA expression data to evaluate the performance of the biclustering algorithms. We detect 19 breast cancer biomarkers by frequency-based method and 5 by network-based method for the miRNA dataset.

Novel developments in the pathogenesis and diagnosis of extranodal marginal zone lymphoma

Extranodal marginal zone lymphoma (EMZL), mostly represented by mucosa-associated lymphoid tissue (MALT) type, also referred to as MALT lymphoma, is a clinically heterogeneous entity within the group of low-grade B cell lymphomas that arises in a wide range of different extranodal sites, including the stomach, lung, ocular adnexa, and skin. It represents the third most common non-Hodgkin lymphoma in the Western world, and the median age of occurrence is around 60 years. One characteristic aspect in a subset of EMZL detectable in about 25% of the cases is the presence of specific chromosomal translocations involving the genes MALT1 and BCL10, which lead to activation of the NF-κB signaling pathway. Another unique aspect is that several infectious agents, such as Helicobacter pylori in the case of gastric EMZL, and autoimmune disorders, like Sjögren syndrome, have been implicated in the pathogenesis of this cancer. Recent findings as summarized in this review have further improved our understanding of the complex pathobiology of this disease and have been essential to better define novel treatment strategies. In addition, many of these specific features are currently being implemented for the diagnosis of EMZL.

The relative contribution of DNA methylation and genetic variants on protein biomarkers for human diseases

Associations between epigenetic alterations and disease status have been identified for many diseases. However, there is no strong evidence that epigenetic alterations are directly causal for disease pathogenesis. In this study, we combined SNP and DNA methylation data with measurements of protein biomarkers for cancer, inflammation or cardiovascular disease, to investigate the relative contribution of genetic and epigenetic variation on biomarker levels. A total of 121 protein biomarkers were measured and analyzed in relation to DNA methylation at 470,000 genomic positions and to over 10 million SNPs. We performed epigenome-wide association study (EWAS) and genome-wide association study (GWAS) analyses, and integrated biomarker, DNA methylation and SNP data using between 698 and 1033 samples depending on data availability for the different analyses. We identified 124 and 45 loci (Bonferroni adjusted P < 0.05) with effect sizes up to 0.22 standard units' change per 1% change in DNA methylation levels and up to four standard units' change per copy of the effective allele in the EWAS and GWAS respectively. Most GWAS loci were cis-regulatory whereas most EWAS loci were located in trans. Eleven EWAS loci were associated with multiple biomarkers, including one in NLRC5 associated with CXCL11, CXCL9, IL-12, and IL-18 levels. All EWAS signals that overlapped with a GWAS locus were driven by underlying genetic variants and three EWAS signals were confounded by smoking. While some cis-regulatory SNPs for biomarkers appeared to have an effect also on DNA methylation levels, cis-regulatory SNPs for DNA methylation were not observed to affect biomarker levels. We present associations between protein biomarker and DNA methylation levels at numerous loci in the genome. The associations are likely to reflect the underlying pattern of genetic variants, specific environmental exposures, or represent secondary effects to the pathogenesis of disease.

Diagnostic value of STMN1, LMO2, HGAL, AID expression and 1p36 chromosomal abnormalities in primary cutaneous B cell lymphomas

AIMS

Distinction between primary cutaneous follicular lymphoma (PCFL) and primary cutaneous marginal zone lymphoma (PCMZL) is challenging, as clear-cut immunophenotypical and cytogenetic criteria to segregate both entities are lacking.

METHODS AND RESULTS

To characterize PCFL and PCMZL more clearly and to define criteria helpful for the differential diagnosis, we compared expression of immunohistochemical markers [LIM-only transcription factor 2 (LMO2), human germinal centre-associated lymphoma (HGAL), stathmin 1 (STMN1), activation-induced cytidine deaminase (AID), myeloid cell nuclear differentiation antigen (MNDA)] and the presence of cytogenetic abnormalities described previously in nodal follicular lymphoma [B cell lymphoma 2 (BCL2) and BCL6 breaks, 1p36 chromosomal region deletion (del 1p36)] in a series of 48 cutaneous follicular and marginal zone lymphomas [cutaneous follicular lymphoma (CFL) and cutaneous marginal zone lymphoma (CMZL)]. Immunostaining for STMN1, LMO2, HGAL and AID allowed the distinction between CFL and CMZL, and STMN1 was the most sensitive marker (100% CFL, 0% CMZL). LMO2, HGAL and AID were positive in 93.2%, 82.1% and 86.2% CFL (all CMZL-negative). MNDA was expressed in both entities without significant difference (10.3% CFL, 30.8% CMZL, P = 0.18). BCL2, BCL6 breaks and the del 1p36 were present in 16.7%, 10.7% and 18.5% CFL and no CMZL. Finally, three and 29 CFL were reclassified as secondary cutaneous follicular lymphomas (SCFL) and PCFL without significant differences concerning phenotypical and cytogenetic features. BCL2, BCL6 breaks and the del 1p36 were present in 11.1%, 8% and 16.7% PCFL and did not impact the prognosis.

CONCLUSION

LMO2, HGAL, STMN1 and AID, but not MNDA, are discriminant for the recognition between CFL and CMZL. BCL2, BCL6 rearrangements and the del 1p36 have a role in the pathogenesis of PCFL, the latest being the most common alteration.

B-cell Non-Hodgkin Lymphomas with Plasmacytic Differentiation

B-cell non-Hodgkin lymphomas with plasmacytic differentiation are a diverse group of entities with extremely variable morphologic features. Diagnostic challenges can arise in differentiating lymphoplasmacytic lymphoma from marginal zone lymphoma and other low-grade B-cell lymphomas. In addition, plasmablastic lymphomas can be difficult to distinguish from diffuse large B-cell lymphoma or other high-grade lymphomas. Judicious use of immunohistochemical studies and molecular testing can assist in appropriate classification.

Splenic marginal zone lymphoma

Splenic marginal zone lymphoma (SMZL) is an indolent small B-cell lymphoma involving the spleen and bone marrow characterized by a micronodular tumoral infiltration that replaces the preexisting lymphoid follicles and shows marginal zone differentiation as a distinctive finding. SMZL cases are characterized by prominent splenomegaly and bone marrow and peripheral blood infiltration. Cells in peripheral blood show a villous cytology. Bone marrow and peripheral blood characteristic features usually allow a diagnosis of SMZL to be performed. Mutational spectrum of SMZL identifies specific findings, such as 7q loss and NOTCH2 and KLF2 mutations, both genes related with marginal zone differentiation. There is a striking clinical variability in SMZL cases, dependent of the tumoral load and performance status. Specific molecular markers such as 7q loss, p53 loss/mutation, NOTCH2 and KLF2 mutations have been found to be associated with the clinical variability. Distinction from Monoclonal B-cell lymphocytosis with marginal zone phenotype is still an open issue that requires identification of precise and specific thresholds with clinical meaning.

Recurrent mutations in genes involved in nuclear factor-κB signalling in nodal marginal zone lymphoma-diagnostic and therapeutic implications

AIMS

To investigate the spectrum of mutations in 20 genes involved in B-cell receptor and/or Toll-like receptor signalling resulting in activation of nuclear factor-κB (NF-κB) in 20 nodal marginal zone lymphomas (NMZLs), 20 follicular lymphomas (FLs), and 11 cases of B-cell lymphoma, unclassifiable (BCL-u).

METHODS AND RESULTS

Nodal marginal zone lymphomas were diagnosed according to strict criteria, including the expression of at least one putative marginal zone marker (MNDA and/or IRTA1). Cases that showed features of NMZL but did not fulfil all criteria were included as BCL-u. All FLs were required to have a BCL2 rearrangement. Mutations were found in: nine NMZLs, with recurrent mutations in TNFAIP3 and CD79B; 12 FLs, with recurrent mutations in TNFRSF14, TNFAIP3, and CARD11; and five cases of BCL-u, with recurrent mutations in TNFRSF14. TNFRSF14 mutations were present in FL and BCL-u, but not in any of the NMZLs. In the BCL-u group, TNFRSF14 mutations clustered with a FL immunophenotype.

CONCLUSIONS

These results suggest that TNFRSF14 mutations point towards a diagnosis of FL, and can be used in the sometimes difficult distinction between NMZL and FL, but to apply this in diagnostics would require confirmation in an independent cohort. In addition, the presence or absence of specific mutations in pathways converging on NF-κB could be important for decisions regarding targeted treatment.

Optimizing therapy for nodal marginal zone lymphoma

Nodal marginal zone lymphoma (NMZL) is a rare form of indolent small B-cell lymphoma which has only been clearly identified in the last 2 decades and which to date remains incurable. Progress in therapeutic management has been slow, largely due to the very small number of patients treated and the heterogeneity of treatments administered; thus, standard-of-care treatment is currently nonspecific for this lymphoma entity. In this review, treatments routinely used to manage adult NMZL patients are presented, principally based on immunochemotherapy (when treatment is needed). Biological research behind the key axes of agents currently under development is described; development of novel agents is heavily based on data from gene profiling and genome-wide sequencing research, uncovering a number of critical deregulated pathways specific to NMZL tumors. These include B-cell receptor, JAK/STAT, NF-κB, NOTCH, and Toll-like receptor signaling pathways, as well as intracellular processes such as the cell cycle, chromatin remodeling, and transcriptional regulation in terms of epigenetic modifiers, histones, or transcriptional co-repressors, along with immune escape via T-cell-mediated tumor surveillance. These pathways are examined in detail and a projection of how the field may evolve in the near future for an efficient personalized treatment approach for NMZL patients is presented.

A subset of low-grade B cell lymphomas with a follicular growth pattern but without a BCL2 translocation shows features suggestive of nodal marginal zone lymphoma

In our consultation practice, it was noted that many cases that were considered to represent follicular lymphoma (FL) without a BCL2 translocation were ultimately classified as nodal marginal zone lymphoma (NMZL). This study set out to define recurrent morphological features of these cases. Thirty-three low-grade B cell lymphomas without a BCL2 rearrangement were studied for recurrent morphological features. These features were then applied on 20 randomly selected cases to verify if these criteria are able to distinguish between lymphomas with and without a BCL2 rearrangement, assigning them to one of five categories ranging from "certain FL" to "certain NMZL." Highly recurrent morphological features were noted in the lymphomas without a BCL2 rearrangement, which were strongly overlapping with the morphological features of NMZL. All six cases that were assigned to the category of certainly FL or most likely FL indeed harbored a BCL2 rearrangement, whereas all 12 cases assigned to the category of most likely NMZL or certain NMZL had no BCL2 break. Of the two cases in the ambiguous category, one had received a final diagnosis of FL and the other of NMZL. This study raises the hypothesis that a subset of low-grade B cell lymphomas with a follicular growth pattern but without a BCL2 translocation actually represents NMZL. This is at present difficult to prove, because no gold standard is available to differentiate between NMZL and FL without a BCL2 rearrangement, so further investigations are needed.

Machine Learning-based Classification of Diffuse Large B-cell Lymphoma Patients by Their Protein Expression Profiles

Characterization of tumors at the molecular level has improved our knowledge of cancer causation and progression. Proteomic analysis of their signaling pathways promises to enhance our understanding of cancer aberrations at the functional level, but this requires accurate and robust tools. Here, we develop a state of the art quantitative mass spectrometric pipeline to characterize formalin-fixed paraffin-embedded tissues of patients with closely related subtypes of diffuse large B-cell lymphoma. We combined a super-SILAC approach with label-free quantification (hybrid LFQ) to address situations where the protein is absent in the super-SILAC standard but present in the patient samples. Shotgun proteomic analysis on a quadrupole Orbitrap quantified almost 9,000 tumor proteins in 20 patients. The quantitative accuracy of our approach allowed the segregation of diffuse large B-cell lymphoma patients according to their cell of origin using both their global protein expression patterns and the 55-protein signature obtained previously from patient-derived cell lines (Deeb, S. J., D'Souza, R. C., Cox, J., Schmidt-Supprian, M., and Mann, M. (2012) Mol. Cell. Proteomics 11, 77–89). Expression levels of individual segregation-driving proteins as well as categories such as extracellular matrix proteins behaved consistently with known trends between the subtypes. We used machine learning (support vector machines) to extract candidate proteins with the highest segregating power. A panel of four proteins (PALD1, MME, TNFAIP8, and TBC1D4) is predicted to classify patients with low error rates. Highly ranked proteins from the support vector analysis revealed differential expression of core signaling molecules between the subtypes, elucidating aspects of their pathobiology.

Clinical aspects of malt lymphomas

Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) is an indolent lymphoma arising in extranodal sites. Several infectious agents and autoimmune disorders have been implicated in its pathogenesis. The stomach represents the most common and best-studied organ involved by MALT lymphoma and its development is strongly associated with Helicobacter pylori (Hp) infection. MALT lymphomas are characterized by an indolent clinical course and excellent survival in most cases, independently of the treatment delivered. Recent progress in the knowledge of the etiology and the cellular and molecular pathological events related to MALT lymphomas allowed us to improve our clinical understanding of this disease entity and to better define treatment strategies.

New Immunohistochemistry for B-Cell Lymphoma and Hodgkin Lymphoma

Context

B-cell non-Hodgkin lymphoma is a heterogeneous group of lymphoproliferative malignancies with different clinical behaviors and treatments. It is important to differentiate individual B-cell lymphoma to apply the best treatment and management. Morphology and immunohistochemistry are the primary tools used for diagnosing lymphoma. There is a characteristic pattern of expression with immunohistochemical antibodies in most well-defined B-cell lymphomas. Some cases of B-cell lymphoma, however, show unusual morphologic and immunophenotypic features. The new and sometimes more specific antibodies have been developed recently, which may further define those lymphomas. Only with use of the antibodies over time does their true nature and specificity become evident.

Objectives

To present new antibodies for B-cell lymphoma that enhance the probability for diagnosis or can act as alternate markers in unusual cases, in which a B-cell lymphoma does not present with characteristic immunohistochemical staining, and to present prognostic markers that allow for better management of patients with specific B-cell lymphomas.

Data Sources

Data were obtained from literature review and figures from slides in personal practice.

Conclusions

The immunohistochemical antibodies presented in this article increase our ability to understand, diagnosis, and manage patients with B-cell lymphoma.

Histiocytoid Sweet syndrome is infiltrated predominantly by M2-like macrophages

BACKGROUND

Histiocytoid Sweet syndrome (HSS) is a rare variant of Sweet syndrome (SS). The nature of histiocytoid cells is still uncertain.

OBJECTIVE

We sought to offer a comprehensive overview on clinical features of HSS and further information on immunohistochemical phenotype of the infiltrate.

METHODS

The clinical, histologic, and immunohistochemical features of 12 of our patients with HSS and all cases retrieved through a PubMed search were analyzed.

RESULTS

Lesions consisted of erythematous-violaceous papules and plaques, randomly distributed mostly on the trunk and the limbs. Three patients had myelodysplastic syndrome and 1 had a monoclonal gammopathy. The infiltrate was mainly composed of CD68(+)CD163(+)myeloperoxidase(+)myeloid cell nuclear differentiation antigen(+)CD117(-)CD15(-)CD34(-), a phenotype suggestive of M2-like macrophages. A few mature neutrophils and lymphocytes were also present. Review of all HSS cases showed no sex predominance and no extracutaneous infiltrates; inconstant presence of fever and blood neutrophilia; association with hematologic or solid neoplasms (26%), autoimmune conditions (12%), and infectious diseases (10%); and good response to steroid treatment, with rare relapses or recurrences.

LIMITATIONS

The study includes a limited case series. The pathogenesis of the disease remains to be clarified.

CONCLUSIONS

HSS lesions are infiltrated mostly by M2-like macrophages. The clinical features present more similarities than differences with SS.

Recognizing nodal marginal zone lymphoma: recent advances and pitfalls. A systematic review

The diagnosis of nodal marginal zone lymphoma is one of the remaining problem areas in hematopathology. Because no established positive markers exist for this lymphoma, it is frequently a diagnosis of exclusion, making distinction from other low-grade B-cell lymphomas difficult or even impossible. This systematic review summarizes and discusses the current knowledge on nodal marginal zone lymphoma, including clinical features, epidemiology and etiology, histology, and cytogenetic and molecular features. In particular, recent advances in diagnostics and pathogenesis are discussed. New immunohistochemical markers have become available that could be used as positive markers for nodal marginal zone lymphoma. These markers could be used to ensure more homogeneous study groups in future research. Also, recent gene expression studies and studies describing specific gene mutations have provided clues to the pathogenesis of nodal marginal zone lymphoma, suggesting deregulation of the nuclear factor kappa B pathway. Nevertheless, nodal marginal zone lymphoma remains an enigmatic entity, requiring further study to define its pathogenesis to allow an accurate diagnosis and tailored treatment. However, recent data indicate that it is not related to splenic or extranodal lymphoma, and that it is also not related to lymphoplasmacytic lymphoma. Thus, even though the diagnosis is not always easy, it is clearly a separate entity.

Clinicopathologic features of CD5-positive nodal marginal zone lymphoma

OBJECTIVES

To describe the clinicopathologic findings of seven patients with CD5-positive nodal marginal zone lymphoma (NMZL).

METHODS

We searched cases of NMZL over a 10-year interval and identified seven cases of CD5-positive NMZL. The clinical, histologic, and immunophenotypic findings of this group were reviewed, and the frequency of dissemination in this group was compared with that of 66 patients with CD5-negative NMZL.

RESULTS

Other than CD5 expression, the histologic and immunophenotypic findings were typical of NMZL. Six (86%) of seven patients had lymphadenopathy above and below the diaphragm, and all six patients assessed had bone marrow involvement. In the CD5-negative group, 28 (42%) patients had lymphadenopathy above and below the diaphragm, and 36 (55%) had bone marrow involvement (P = .045 and P = .037, respectively). Six of seven patients were alive at last follow-up, with a median follow-up of 32 months (3-154 months).

CONCLUSIONS

CD5 expression in NMZL correlates with a higher frequency of dissemination, but patients have an indolent clinical course and excellent overall survival.

Selective immunophenotyping for diagnosis of B-cell neoplasms: immunohistochemistry and flow cytometry strategies and results

Determining the immunophenotype of hematologic malignancies is now an indispensable part of diagnostic classification, and can help to guide therapy, or to predict clinical outcome. Diagnostic workup should be guided by morphologic findings and evaluate clinically important markers, but ideally should avoid the use of overly broad panels of immunostains that can reveal incidental findings of uncertain significance and give rise to increased costs. Here, we outline our approach to diagnosis of B-cell neoplasms, combining histologic and clinical data with tailored panels of immunophenotyping reagents, in the context of the 2008 World Health Organization classification. We present data from cases seen at our institution from 2004 through 2008 using this approach, to provide a practical reference for findings seen in daily diagnostic practice.

VR09 cell line: an EBV-positive lymphoblastoid cell line with in vivo characteristics of diffuse large B cell lymphoma of activated B-cell type

BACKGROUND

small B-cell neoplasms can show plasmacytic differentiation and may potentially progress to aggressive lymphoma (DLBCL). Epstein-Barr virus (EBV) infection may cause the transformation of malignant cells in vitro.

DESIGN AND METHOD

we established VR09 cell line with plasmacytic differentiation, obtained from a case of atypical, non-CLL B-cell chronic lymphoproliferative disease with plasmacytic features. We used flow cytometry, immunohistochemistry, polymerase chain reaction, cytogenetic analysis and florescence in situ hybridization in the attempt at thoroughly characterizing the cell line. We showed VR09 tumorigenic potential in vivo, leading to the development of activated DLBCL with plasmacytic features.

RESULTS

VR09 cells displayed plasmacytic appearance and grew as spherical tumors when inoculated subcutaneously into immunodeficient Rag2(-/-) γ-chain(-/-) mice. VR09 cell line and tumors displayed the phenotype of activated stage of B cell maturation, with secretory differentiation (CD19+ CD20+ CD79a+ CD79b+/- CD138+ cyclin D1- Ki67 80% IgM+ IgD+ MUM1+ MNDA+ CD10- CD22+ CD23+ CD43+ K+, λ- Bcl2+ Bcl6-) and they presented episomal EBV genome, chromosome 12 trisomy, lack of c-MYC rearrangement and Myd88 gene mutation, presence of somatic hypermutation in the VH region, and wild-type p53.

CONCLUSION

This new EBV-positive cell line may be useful to further characterize in vivo activated DLBCL with plasmacytic features.

Absence of TCL1A expression is a useful diagnostic feature in splenic marginal zone lymphoma

Splenic marginal zone lymphoma (SMZL) is a low-grade lymphoma showing a rather nonspecific immunophenotype. Gene expression profiling studies suggested that TCL1A could be a marker of SMZL, but reported data are conflicting. We evaluated TCL1A expression in a series of spleen and bone marrow samples involved by SMZL and correlated the findings with other immunophenotypical, morphological, and clinical data. In addition, we evaluated the expression of TCL1A in a series of spleens and lymph nodes involved by lymphomas that might mimic SMZL (13 nodal marginal zone lymphomas (NMZL), 39 follicular lymphomas (FL), 30 B-cell chronic lymphocytic leukemias (B-CLL), 31 mantle cell lymphomas (MCL), 1 lymphoplasmacytic lymphoma) and 15 bone marrow specimens involving hairy cell leukemia (HCL). TCL1A staining was negative in 24/31 cases of SMZL (77 %); 27/31 MCL and all B-CLL were positive for TCL1A; 32/34 cases of nodal FL (96 %) and all five splenic FL were positive for TCL1A, although at a lower intensity. Eight of 13 NMZL were positive for TCL1A, often showing a heterogeneous staining pattern. All HCL samples were strongly positive for TCL1A. No correlation was found between the pattern of splenic infiltration, TCL1A expression, and the clinical course. TCL1A-positive SMZL showed a higher rate of DBA44 staining compared to the negative ones, and this difference was statistically significant (Fisher test, single-tailed, p = 0.0397). Our data support the use of TCL1A in the panel of diagnostic markers used in the differential diagnosis of splenic low-grade B-cell lymphoma; a possible prognostic value, however, needs a larger series to be established.

Evaluation of flow cytometric assessment of myeloid nuclear differentiation antigen expression as a diagnostic marker for myelodysplastic syndromes in a series of 269 patients

BACKGROUND

Myeloid nuclear differentiation antigen (MNDA) is expressed in myelomonocytic cells with highest levels in mature granulocytes and monocytes. It is suggested to be expressed more weakly in patients with myelodysplastic syndromes (MDS). The analysis of MNDA therefore may improve diagnostic capabilities of multiparameter flow cytometry (MFC) in MDS.

METHODS

We used MFC for detection of MNDA expression in 269 patients with suspected or known MDS, acute myeloid leukemia (AML) or chronic myelomonocytic leukemia (CMML), cytopenia of unknown cause or without malignancy (negative controls). Results were compared with the diagnoses revealed by cytomorphology (CM) and cytogenetics (CG).

RESULTS

Percentages of granulocytes and monocytes with diminished MNDA expression (dimG and dimM) were higher in patients with MDS (mean ± SD, 20% ± 20%, P < 0.001 and 31% ± 24%, P < 0.001) and AML (27% ± 27%, P = 0.007 and 45% ± 31%, P = 0.001) diagnosed by CM, vs. patients without MDS (8% ± 10% and 16% ± 11%), respectively. Significant differences were also found for mean fluorescence intensity (MFI) of MNDA in monocytes which was lower in MDS (mean ± SD, 71 ± 36, P = 0.004) and AML (55 ± 39, P < 0.001) vs. no MDS samples (85 ± 28), respectively. Within patients with MDS, cases with cytogenetic aberrations showed a trend to higher %dimG (24% ± 18%, P = 0.083) compared with those without (16% ± 21%). Cut-off values for %dimG (12%) and %dimM (22%) as well as for MFI in monocytes (72) were defined capable of discriminating between MDS and non-MDS.

CONCLUSION

MNDA expression in bone marrow cells can be assessed reliably by MFC and may facilitate evaluation of dyspoiesis when added to a standard MDS MFC panel.