Pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma: additional evidence to support they are a single disease with variation in the histologic spectrum.

Pediatric-type follicular lymphoma (PTFL) and pediatric nodal marginal zone lymphoma (PNMZL) are two rare indolent B-cell lymphomas with overlapping features. Recently, cases showing hybridizing features of PTFL and PNMZL have been reported. Herein, we retrospectively analyzed the clinicopathologic features of 59 patients, including 39 with PTFL, 5 with PNMZL, and 15 with mixed-type tumors (MTT). And next-generation sequencing analysis was performed on 3 PTFL, 2 PNMZL, and 2 MTT cases. In addition, previously published mutational data of 96 PTFLs, 25 PNMZLs, and 46 MTTs were also analyzed. There were 52 male and 7 female patients, with a median age of 17 years. Most patients (96.6%) had lymph node involvement in the head and neck region and were diagnosed with stage I disease. Among the 50 patients (85%) with telephone follow-up, 44 (88%) adopted a watch-and-wait strategy after surgical resection of the lesions. Only one PTFL patient experienced a relapse 6 months after diagnosis. Microscopically, not only the MTT cases showed a composite form of enlarged follicles and interfollicular lymphocytic proliferation producing a progressively transformed germinal center (PTGC) pattern, but also focal follicles with a PTGC-like pattern were observed in PTFL cases. Genetically, the most frequently mutated genes were TNFRSF14 (in 3 PTFLs and 2 MTTs), MAP2K1 (in 2 PTFLs, 1 PNMZL and 1 MTT), and IRF8 (in 2 MTTs and 1 PNMZL). Based on the similar or overlapping clinical, pathologic, and genetic features, PTFL and PNMZL are likely to represent two different histologic patterns of the same disease.

Fever and Chimpanzees: An Unexpected Life-Threatening Diagnosis.

Tropic fever can have several causes. It is important to investigate thoroughly and consider less obvious explanations. This paper presents the case of a biologist in close contact with chimpanzees, who developed fever in the tropics. Despite treatment for some tropical diagnosis, the fever persisted. On arrival in Belgium, further diagnostics revealed an unexpected diagnosis: Citrobacter koseri endocarditis of the native aortic valve. He was treated with ceftriaxone and amikacin and underwent aortic valve replacement. C koseri is a commensal in humans and animals. It is likely that the patient was infected with this bacterium through his close contact with chimpanzees. Only a few cases of C koseri endocarditis have been published worldwide, with most patients being immunocompromised. Patients with tropical fever may have unsuspected underlying causes, like endocarditis.

A Rare Case of Refractory Nodal Marginal Zone Lymphoma in a Child, Successfully Cured by Allogeneic Stem Cell Transplant: A Case Report.

BACKGROUND: Nodal marginal zone lymphoma (NMZL) is a rare form of non-Hodgkin lymphoma (NHL), accounting for around 2% of all NHL in pediatrics and adults. It is considered the least common subtype of marginal zone lymphoma, which is rarely seen in pediatrics and is usually viewed as a mild disease. In adults, its presentation varies from mild to aggressive disease with multiple lymph node enlargement and systemic symptoms. CASE REPORT: Here, we report an interesting case of a 31-month-old boy who developed refractory EBV-positive NMZL with extensive disease. The tumor did not respond well to conventional chemotherapy and Rituximab. Therefore, we manage the disease with second-line chemotherapy, including bortezomib, followed by an allogeneic hematopoietic stem cell transplant (HSCT) with an excellent outcome. CONCLUSION: Very few cases have been reported for aggressive NMZL children. The tumor was refractory to first line chemotherapy. However, the successful outcome was achieved by allogeneic stem cell transplant with myeloablative conditioning chemotherapy. The significance of this particular case is that this is the first reported case from pediatrics for refractory NMZL, which responded well to allogeneic stem cell transplant.

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.

Comparison of histological and molecular features of pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma.

Pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma are pediatric B cell lymphomas with similar clinical characteristics but distinct histological features. We investigated the differences between pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma by comparing their histological and molecular characteristics. A total of 5 pediatric-type follicular lymphoma and 11 pediatric nodal marginal zone lymphoma patients were included in the study. In the histological review, 5 of the 16 cases showed overlapping morphological features of pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma; hence, they were reclassified as "mixed type." In molecular analysis, using panel-based massively parallel sequencing, MAP2K1, TNFRSF14, and IRF8 mutations were found in 6, 3, and 2 of the 11 pediatric nodal marginal zone lymphoma patients, respectively, and IRF8 mutation was found in one of the five pediatric-type follicular lymphoma patients. There were no significant differences in genetic alterations established from the histologically reclassified diagnosis as well as the initial diagnosis. Pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma showed morphological overlap in some cases, and no difference between the two was found upon molecular analysis. These findings suggest the possibility that pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma are single entity pediatric B-cell lymphoma with broad morphological spectrum.

Atypical nontraumatic chylothorax in a monoclonal IgM elevated nodal marginal zone lymphoma: A case report and review of the literature.

Nodal Marginal Zone Lymphoma(NMZL) is an indolent lymphoma with a very low clinical incidence and is sometimes difficult to differentiate diagnostically from Lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia (LPL/WM). NMZL with elevated monoclonal immunoglobulin M (IgM) is even rarer. Nontraumatic chylothorax can be seen in aggressive lymphoma, which often happens with chest tightness and dyspnea as the primary clinical manifestation. We reported the first case of monoclonal IgM elevated NMZL complicated by atypical nontraumatic chylothorax. A 64-year-old male patient was first admitted to the Department of Respiratory Medicine with symptoms of chest tightness and shortness of breath. He was given several times thoracentesis to drain pleural effusion to improve pulmonary compression symptoms. The patient had a combination of elevated monoclonal IgM and atypical lymph node biopsy pathology. After two times lymph node biopsies and genetic testing, the patient was finally diagnosed with NMZL. Within a short time, he was admitted to the Department of Hematology due to the reappearance of massive pleural effusion, which indicated chylothorax. The patient repeatedly presented with left-sided pleural effusion, and the color went from red to yellow, and finally white. Only about half of the chylothorax cases present with typical clinical manifestations. We report this case intending to draw the attention of clinicians to hematologic malignancies with atypical nontraumatic chylothorax.

Immunotactoid glomerulopathy - an enigmatic case in the setting of nodal marginal zone lymphoma and systemic sclerosis sine scleroderma.

BACKGROUND: Immunotactoid Glomerulopathy (ITG) is an exceedingly rare type of glomerulopathy characterised by distinctive electron microscopic features. ITG has been linked to lymphoproliferative or autoimmune disorders. The clinical manifestations are diverse including nephrotic syndrome (NS), haematuria, acute kidney injury and end stage renal failure (ESRD). We present a case with a stage 3 Nodal Marginal Zone Lymphoma (NMZL) and systemic sclerosis sine scleroderma (SSSS), where the evolution of ITG was documented in 2 renal biopsies 19 months apart. To the best of our knowledge, no cases have been reported linking ITG to NMZL. Furthermore, there is only one non-peer reviewed report linking ITG to scleroderma. We discuss the implications of our findings and highlight the satisfactory management of the case. CASE PRESENTATION: A 79-year-old female with history of systemic sclerosis sine scleroderma and stage 3 NMZL presented with acute kidney injury and NS on a background of chronic kidney disease. Her first kidney biopsy showed a diffuse proliferative glomerulonephritis and her serum protein electrophoresis showed no abnormalities. She was managed satisfactorily with conservative measures. She returned 19 months later with features of fluid overload, increasing proteinuria and rising serum creatinine. A repeat serum protein electrophoresis showed excess free kappa light chains and ITG was detected in the repeat kidney biopsy. Her kidney function and proteinuria showed a good and sustained response to rituximab administered after the second biopsy. CONCLUSION: ITG is a rare type of glomerulopathy, associated with underlying haematological malignancies and autoimmune disorders that may result in ESRD. Rituximab is one of the effective agents used in the management of ITG with haematological malignancies.

Helicobacter pylori-negative extra-nodal marginal zone B-cell lymphoma of Mucosa-Associated Lymphoid Tissue (MALT) type following Roux-en-Y Gastric Bypass (RYGB).

Gastric MALT lymphoma is a common type of non-Hodgkin's lymphoma that has the potential for cure in patients found to have concomitant Helicobacter pylori (H. pylori) infection. This case report explores the evaluation, diagnosis, and treatment of H. pylori-negative MALT lymphoma in a patient with a history of a RYGB.

[Marginal zone lymphoma associated with Reed-Sternberg cells: A challenge for the pathologist]. / Lymphome de la zone marginale ganglionnaire associé à des cellules de Reed-Sternberg : un challenge pour le pathologiste.

We report the case of a 46-year-old male patient presenting with a Claude Bernard-Horner Syndrome. Clinical evaluation showed a clonal B-cell population, lambda restricted. PET-scan captured femoral and axillary lymph nodes. Therefore the diagnosis of a marginal zone lymphoma was posted for which an attitude of watchful waiting was suggested. Eighteen months later, the patient developed an inguinal adenopathy. This lymph node led to the diagnosis of a nodular sclerosing Hodgkin lymphoma. Initial treatment with ABVD showed a good response, but the patient relapsed after eight months. A second biopsy confirmed the diagnosis of a marginal zone lymphoma but also identified giant Reed-Sternberg cells, (CD15+, CD30+ and CD20+). The initial biopsy was revised. This last diagnosis of a nodal marginal zone lymphoma with presence of Reed-Sternberg cells is rarely described in the literature. Several scientific theories can be found. Some cases described a transformation of non-Hodgkin lymphoma that presented Reed-Sternberg cells, other cases mentioned a collision or composite tumor. An accidental finding of Reed-Sternberg cells can be seen by after an infectious disease such as EBV. The presence of only Reed-Sternberg cells in a non-Hodgkin lymphoma is not sufficient to make a diagnosis of collision tumor.

Long-Term Observation of the Progression From Nodal Marginal Zone Lymphoma to Diffuse Large B-Cell Lymphoma in a Dog.

A 4-year and 10-month old female Pembroke Welsh Corgi presented with an enlarged right popliteal lymph node, and a histopathological diagnosis of nodal marginal zone lymphoma (nMZL) was made. After resection of the lymph node, follow-up observation was continued without chemotherapy. At 22 months after initial presentation, the dog developed enlargement of peripheral lymph nodes, and the histopathological diagnosis was late-stage nMZL. Multidrug chemotherapy induced clinical complete remission, but the tumor relapsed with enlargement of peripheral and abdominal lymph nodes 42 months after initial presentation. Second-round multidrug chemotherapy induced complete clinical remission again; however, the tumor relapsed with lymphadenopathy 47 months after initial presentation. The dog died 59 months after initial presentation, and postmortem examination revealed generalized lymphadenopathy; the histopathological diagnosis was diffuse large B-cell lymphoma (DLBCL). Polymerase chain reaction for antigen receptor gene rearrangements revealed that the nMZL and DLBCL samples were derived from the same B-lymphocyte clone.

[Transformation of CD5-positive nodal marginal zone lymphoma to diffuse large B-cell lymphoma].

Nodal marginal zone lymphoma (NMZL) is a form of nodal B-cell lymphoma exhibiting proliferation of abnormal lymphocytes at the circumference of the mantle zone in the lymph nodes. Although the outcome of patients with this disease is often favorable, we recently encountered a patient with a CD5-positive NMZL who was resistant to chemotherapy. A 67-year-old woman complaining of systemic lymph node swelling was referred to our hospital. After biopsy of the neck lymph node, she was diagnosed with CD5-positive NMZL. Disease progression was revealed after 16 months, and she was initially treated with chemotherapy consisting of rituximab, cyclophosphamide, vincristine, and prednisolone (R-CVP). However, this therapy was ineffective. Subsequent therapy with rituximab and bendamustine also failed to induce remission. A rebiopsy revealed that the NMZL had transformed into a diffuse large B-cell lymphoma. This patient died after 2 years from the initial diagnosis due to lymphoma progression. Cases of CD5-positive NMZL are rare; thus, it is difficult to study the clinical implications of CD5 expression in this disease. Here we describe the current understanding of CD5 expression in NMZL.

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.

Lymphoplasmacytic Lymphoma and Marginal Zone Lymphoma.

Lymphoplasmacytic lymphoma (LPL) and marginal zone lymphoma (MZL) are indolent subtypes of non-Hodgkin lymphoma. Both are typically CD5 and CD10 negative. In recent years, there have been several scientific advances that have helped improve the diagnosis of these conditions. These conditions have been managed similarly in previous years with observation in asymptomatic patients and systemic therapy in advanced stages. However, there are specific differences. Differential responses are also seen with novel agents such as the BTK inhibitor ibrutinib. It is encouraging to see that there several clinical trials specific for patients with LPL and MZL ongoing.

Antiphospholipid antibodies associated with nodal marginal zone lymphoma and its progression to diffuse large B-cell lymphoma-A case report.

An association between autoimmune events, as well as the development of antiphospholipid (aPL) antibodies and lymphoproliferative disorders is well recognized. We present the patient with coagulation abnormalities and non-Hodgkin lymphoma (NHL), primarily diagnosed as nodal marginal zone B-cell lymphoma (NMZL), and in relapse as diffuse large B-cell lymphoma (DLBCL). In the follow-up period, the patient simultaneously developed different aPL antibodies. The presence of aPL antibodies in NHL is frequent but it is not common in the NMZL. The aim of the present case report is to highlight the possible underlying increase of aPL antibodies in NMZL patients with coagulation tests abnormalities.

Molecular pathogenesis of splenic and nodal marginal zone lymphoma.

Genomic studies have improved our understanding of the biological basis of splenic (SMZL) and nodal (NMZL) marginal zone lymphoma by providing a comprehensive and unbiased view of the genes/pathways that are deregulated in these diseases. Consistent with the physiological involvement of NOTCH, NF-κB, B-cell receptor and toll-like receptor signaling in mature B-cells differentiation into the marginal zone B-cells, many oncogenic mutations of genes involved in these pathways have been identified in SMZL and NMZL. Beside genetic lesions, also epigenetic and post-transcriptional modifications contribute to the deregulation of marginal zone B-cell differentiation pathways in SMZL and NMZL. This review describes the progress in understanding the molecular mechanism underlying SMZL and NMZL, including molecular and post-transcriptional modifications, and discusses how information gained from these efforts has provided new insights on potential targets of diagnostic, prognostic and therapeutic relevance in SMZL and NMZL.

Nodal marginal zone lymphoma: Clinical features, diagnosis, management and treatment.

Nodular marginal zone lymphoma (NMZL) is a small B-cell lymphoma involving only lymph nodes and is the least common form of MZL constituting about 10% of cases. Patients usually present with advanced disease which must be distinguished from extranodal MZL with lymph node spread. NMZL shares cytological and immunophenotypic features with MALT and splenic MZL, but has a less favorable prognosis than these two categories. It occurs mostly in adults and pediatric cases are rare. Different therapeutic approaches have been used in NMZL, but because of the small patient numbers involved, more definitive treatment is still anticipated. Recent studies suggest that it probably represents a separate entity within the broader indolent lymphoma category. In NMZL there is an emerging need to utilize novel agents, already available for indolent lymphomas. Prospective studies are required to evaluate their therapeutic efficacy for NMZL in the future.

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.

The bendamustine plus rituximab regimen is active against primary nodal marginal zone B-cell lymphoma.

Primary nodal marginal zone lymphoma (NMZL) is a rare disease. There is no current consensus on how to treat it. The bendamustine plus rituximab (BR) regimen is effective for the treatment of follicular and other indolent lymphomas, but its efficacy in NMZL is not known. We analyzed the outcome of 14 patients diagnosed with NMZL (median age 67 years) who were treated with 375 mg/m2 of rituximab on day 1 and 90 mg/m2 of bendamustine on days 1 and 2. The overall and complete response rates were 93% and 71%, respectively. Major toxicity (grade 3/4 neutropenia) occurred in 5% of treatment courses. After a median follow-up of 22 months (range: 18-55), the overall survival and the free survival rates were 100% and 93%, respectively. None of the patients showing a complete or partial response developed secondary myelodysplastic syndrome/acute myeloid leukemia. Bendamustine plus rituximab was found to be an active and well-tolerated regimen leading to the rapid control of disease.