Splenic marginal zone lymphoma

Splenic Marginal Zone Lymphoma in a Patient With Antiphospholipid Syndrome Treated With Rituximab: A Case Report

Splenic marginal zone lymphoma (SMZL) usually presents with splenomegaly or symptoms related to cytopenia. We report a case of a 56-year-old female with previously diagnosed antiphospholipid syndrome (APS) on warfarin therapy who initially presented with abdominal pain and was found to have massive splenomegaly and splenic infarction on CT imaging. Initial clinical presentations and imaging findings were attributed to the subtherapeutic coagulation profile. The patient was later diagnosed with SMZL following workup for pancytopenia including bone marrow biopsy, flow cytometry, and PET scan. Cytopenias, splenomegaly, and abnormal metabolic activity in the spleen on the PET scan improved after treatment with four cycles of weekly rituximab. Our report presents a case of a patient with longstanding APS presenting with splenic infarction and pancytopenia who was subsequently diagnosed with SMZL and successfully treated with rituximab.

Optical genomic mapping is a helpful tool for detecting CCND1 rearrangements in CD5-negative small B-cell lymphoma: Two cases of leukemic non-nodal mantle cell lymphoma

Optical genome mapping (OGM) is a new DNA-based technology which provides comprehensive examination of the entire genome. We report two patients who presented with splenomegaly and leukocytosis with lymphocytosis including villous lymphocytes. Neither patient had lymphadenopathy. Bone marrow evaluation showed involvement by small B-cell lymphoma in a sinusoidal and interstitial distribution, and immunophenotypic analysis showed that the neoplastic cells were positive for B-cell markers and cyclin D1 but were negative for SOX11 and CD5. Initially, the clinicopathologic features in both patients were thought to be suspicious for hairy cell leukemia variant or splenic marginal zone lymphoma. However, OGM detected CCND1 rearrangement: t(2;11)/IGK::CCND1 in one case and t(11;14)/IGH::CCND1 in the other case. These cases illustrate the valuable role OGM can play in establishing the diagnosis of MCL. Case 1 also contributes to the paucity of literature on the rare occurrence of IGK::CCND1 in MCL.

Sclerotic marginal zone lymphoma: A case report

BACKGROUND

Marginal zone lymphoma (MZL) is an indolent non-Hodgkin B cell lymphoma with various architectural pattern including perifollicular, follicular colonization, nodular, micronodular, and diffuse patterns. A sclerotic variant has not been previously reported and represents a diagnostic pitfall.

CASE SUMMARY

A 66-year-old male developed left upper extremity swelling. Chest computed tomography (CT) in September 2020 showed 14 cm mass in left axilla. Needle core biopsy of axillary lymph node showed sclerotic tissue with atypical B lymphoid infiltrate but was non-diagnostic. Excisional biopsy was performed for diagnosis and showed extensive fibrosis and minor component of infiltrating B cells. Flow cytometry showed a small population of CD5-, CD10-, kappa restricted B cells. Monoclonal immunoglobulin heavy chain and light chain gene rearrangement were identified. Upon being diagnosed with MZL, patient was treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone and achieved complete remission by positron emission tomography/CT.

CONCLUSION

This is an important case report because by morphology this case could have easily been overlooked as non-specific fibrosis with chronic inflammation representing a significant diagnostic pitfall. Moreover, this constitutes a new architectural pattern. While sclerotic lymphomas have rarely been described (often misdiagnosed as retroperitoneal fibrosis), we do not know of any cases describing this architectural presentation of MZL.

Factors associated with bone marrow involvement in lymphoma staging bone marrow examination: A South African single-centre retrospective study

Background: Accurate detection of bone marrow involvement (BMI) in lymphoma is important as it signifies stage 4 disease. Staging bone marrow examination (BME), therefore, influences treatment decisions and prognostication. The prevalence of BMI depends on multiple factors at presentation including lymphoma subtype, age, sex, human immunodeficiency virus (HIV) status and haematological parameters.Aim: To determine risk factors for BMI in lymphoma staging.Setting: The study was conducted in the department of haematological pathology, Tygerberg Hospital, Cape Town, South Africa.Methods: Retrospective cross-sectional descriptive study in adult patients, reviewing BMI and associated parameters, during their initial lymphoma staging procedure between 2016 and 2019.Results: Of a total of 387 lymphoma staging cases that were evaluated, 30.0% of them showed BMI. Diffuse large B-cell lymphoma, Hodgkin lymphoma and high-grade B-cell lymphoma were the most frequent subtypes diagnosed. The highest prevalence of BMI was in low-grade lymphomas. There was a statistically significant association between BMI and advanced age, pancytopenia and bicytopenia (anaemia with leucopenia, anaemia with thrombocytopenia or leucopenia with thrombocytopenia). Bicytopenia and pancytopenia showed high positive predictive values of BMI, respectively, 61.0% and 69.0%. Human immunodeficiency virus positivity (34.6%) was not predictive of BMI across all lymphoma subtypes. Normal blood counts had a high negative predictive value for BMI.Conclusion: BME remains an important part of lymphoma staging with 30.0% of all lymphomas showing BMI.

Treatment of indolent lymphoma

Treatment of indolent lymphoma has improved significantly in recent decades since the advent of rituximab (anti-CD20 monoclonal antibody). Although, some patients with limited disease can be cured with radiation therapy alone, most patients experience disease progression and recurrence during follow-up despite early initiation of treatment. Thus, watch-and-wait is still regarded the standard for asymptomatic patients. Patients with indolent lymphoma have a significant heterogeneity in terms of tumor burden, symptoms (according to anatomical sites) and the need for instant therapy. Therefore, the initiation of treatment and treatment option should be decided with a clear goal in each patient according to the need for therapy and clinical benefits with the chosen treatment. In this review, we cover the current treatment of follicular lymphoma and marginal zone lymphoma.

Superior outcome for splenectomised patients in a population-based study of splenic marginal zone lymphoma in Sweden

Splenic marginal zone lymphoma (SMZL) is a rare low-grade B-cell lymphoma where associations with viral hepatitis and autoimmune and inflammatory diseases (AID) have been indicated. We aimed at assessing the prevalence of viral hepatitis and AID at SMZL diagnosis and outcome by treatment in a Swedish population-based study. A total of 277 SMZL patients registered in the Swedish Lymphoma Register in 2007-2017 were included. A history of viral hepatitis was reported in five (2%) patients and AID prior to SMZL in 72/240 (30%) patients. Treatment was given up front for 207 (75%) patients. Splenectomy with or without systemic treatment was performed in 119 (57%) and was associated with statistically significantly better overall survival [hazard ratio, HR = 0·47 (95% confidence interval, CI: 0·23-0·93), P = 0·03] and progression-free survival (HR = 0·55, 95% CI: 0·35-0·86, P = 0·008) compared to non-splenectomised patients in multivariable analyses. The up-front splenectomised group was younger and generally had a lower Ann Arbor stage, but also more frequently B symptoms and high lactate dehydrogenase than the non-splenectomised group. Viral hepatitis and AID history did not affect SMZL outcome. We report high incidence of AIDs and low incidence of viral hepatitis in this population-based study of SMZL. Splenectomy up front was associated with a favourable outcome.

RNA sequencing analyses reveal differentially expressed genes and pathways as Notch2 targets in B-cell lymphoma

Splenic marginal zone lymphoma (SMZL) is a low grade, indolent B-cell neoplasm that comprises approximately 10% of all lymphoma. Notch2, a pivotal gene for marginal zone differentiation is found to be mutated in SMZL. Deregulated Notch2 signaling has been involved in tumorigenesis and also in B-cell malignancies. However the role of Notch2 and the downstream pathways that it influences for development of B-cell lymphoma remains unclear. In recent years, RNA sequencing (RNA-Seq) has become a functional and convincing technology for profiling gene expression and to discover new genes and transcripts that are involved in disease development in a single experiment. In the present study, using transcriptome sequencing approach, we have identified key genes and pathways that are probably the underlying cause in the development of B-cell lymphoma. We have identified a total of 15,083 differentially expressed genes (DEGs) and 1067 differentially expressed transcripts (DETs) between control and Notch2 knockdown B cells. Gene Ontology (GO) term enrichment and pathway analysis were applied for the identification of key genes and pathways involved in development of B-cell lymphoma. In addition, intermediate genes of top canonical pathways such as PI3K/AKT and NF-kB were found to be downregulated with Notch2 knockdown, indicating that these pathways could be the putative downstream effectors through which Notch2 mediates its oncogenic effects. Taken collectively, the identified crop of genes and pathways may be considered as targets for the treatment of B-cell lymphoma.

Identification of a Splenic Marginal Zone Lymphoma Signature: Preliminary Findings With Diagnostic Potential

Splenic marginal zone lymphoma (SMZL) is a rare, indolent non-Hodgkin's lymphoma that affects 0. 13 per 100,000 persons annually. Overall survival of SMZL is estimated to reach 8-11 years in most cases, but up to 30% of SMZL cases develop aggressive presentations resulting in greatly diminished time of survival. SMZL presents with a very heterogeneous molecular profile, making diagnosis problematic, and accurate prognosis even less likely. The study herein has identified a potential diagnostic gene expression signature with highly specific predictive utility, coined the SMZL-specific Gene Expression Signature (SSGES). Additionally, five of the most impactful markers identified within the SSGES were selected for a five-protein panel, for further evaluation among control and SMZL patient samples. These markers included EME2, ERCC5, SETBP1, USP24, and ZBTB32. When compared with control spleen and other B-cell lymphoma subtypes, significantly higher expression was noticed in SMZL samples when stained for EME2 and USP24. Additionally, ERCC5, SETBP1, USP24, and ZBTB32 staining displayed indications of prognostic value for SMZL patients. Delineation of the SSGES offers a unique SMZL signature that could provide diagnostic utility for a malignancy that has historically been difficult to identify, and the five-marker protein panel provides additional support for such findings. These results should be further investigated and validated in subsequent molecular investigations of SMZL so it may be potentially incorporated into standard oncology practice for improving the understanding and outlook for SMZL patients.

Splenectomy in Lymphoproliferative Disorders: A Single Eastern European Center Experience

Background and Objectives: Hematological malignancies are usually systemic diseases of life-threatening impact, and frequently require prompt and energetic therapeutic intervention. Due to systemic involvement, the role of surgery is generally limited to diagnostic approaches, and it is very rarely employed as a therapeutic modality. Splenectomy represents an exception to this paradigm, being used both as a diagnostic and tumor debulking procedure, notably in splenic lymphomas. Materials and Methods: We investigated the role of splenectomy in a single center prospective study of splenectomy outcome in patients with splenic involvement in the course of lymphoproliferative disorders. In the present study, we included all patients treated in our department for lymphoid malignancies over a period of six years, who underwent splenectomy as a diagnostic or debulking procedure after referral and workup, or had been referred to our department after first being splenectomized and diagnosed with splenic lymphoma. Patient characteristics and treatment outcome were investigated. Results: We enrolled 54 patients, with 34 (63%) splenectomized patients: 12 splenectomies (22.2%) for diagnostic purposes and 22 (40.7%) for treatment. Special attention was given to the 28 (51.85%) patients diagnosed with splenic marginal zone lymphoma (SMZL), a subtype with a clear therapeutic indication for splenectomy. Average age of patients was 57.5 (±13.1) years with a higher prevalence of feminine gender (66.67%). Age above 60 years old (p = 0.0295), ECOG (Eastern Cooperative Oncology Group) > 2 (p = 0.0402) and B-signs (p nonsignificant (NS)) were most frequently found in SMZL patients. Anemia, and notably autoimmune anemia, was more frequent in SMZL versus other small-cell lymphomas and also in splenectomized patients, as was leukocytosis and lymphocytosis. Treatment of patients with lymphoproliferative disorders consisted of chemotherapy and/or splenectomy. Most SMZL patients received chemotherapy as first line treatment (61.5%) and had only partial response (57.7%). Second treatment line was splenectomy in 80% of patients who required treatment, followed by a 60% rate of complete response (CR). Splenectomy offered a higher complete response rate (twice as high than in non-splenectomized, regardless of histology type, p = NS), followed by a survival advantage (Overall Survival (OS)~64 versus 59 months, p = NS). Particularly, SMZL patients had a 4.8 times higher rate of CR than other non-Hodgkin lymphoma (NHL) patients (p = 0.04), a longer progression free survival (73 months vs. 31 months for other small-cell NHLs p = NS) and a 1.5fold lower death rate (p = NS). The procedure was rather safe, with a 38.5% frequency of adverse reactions, mostly minor and manageable. Conclusions: Our data suggest that splenectomy is an effective and safe therapeutic option in patients with lymphoid malignancies and splenic involvement, particularly splenic marginal zone lymphoma.

The Possible Role of Gut Microbiota and Microbial Translocation Profiling During Chemo-Free Treatment of Lymphoid Malignancies

The crosstalk between gut microbiota (GM) and the immune system is intense and complex. When dysbiosis occurs, the resulting pro-inflammatory environment can lead to bacterial translocation, systemic immune activation, tissue damage, and cancerogenesis. GM composition seems to impact both the therapeutic activity and the side effects of anticancer treatment; in particular, robust evidence has shown that the GM modulates the response to immunotherapy in patients affected by metastatic melanoma. Despite accumulating knowledge supporting the role of GM composition in lymphomagenesis, unexplored areas still remain. No studies have been designed to investigate GM alteration in patients diagnosed with lymphoproliferative disorders and treated with chemo-free therapies, and the potential association between GM, therapy outcome, and immune-related adverse events has never been analyzed. Additional studies should be considered to create opportunities for a more tailored approach in this set of patients. In this review, we describe the possible role of the GM during chemo-free treatment of lymphoid malignancies.

18F-FDG PET/CT in splenic marginal zone lymphoma

PURPOSE

The detection rate and the metabolic behavior of 18F-FDG-PET/CT in splenic marginal zone lymphoma (SMZL) are not yet clear. Our aim was to investigate the metabolic behavior of SMZL and whether the tumor stage (acc. Ann Arbor) epidemiological (age, gender), histological (Ki-67 index, plasmacytic differentiation), and morphological (splenic diameter maximum) features might be related to 18F-FDG PET/CT results.

METHODS

Fifty-one patients (34 male, 17 female; average age 70 years) with histologically confirmed SMZL who underwent a 18F-FDG PET/CT for initial staging were included: PET/CT images were analyzed visually and semi-quantitatively (SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio). Splenic uptake was divided as diffuse or focal.

RESULTS

Thirty-nine patients (76%) had FDG-avid SMZL (7 with focal splenic lesions and 32 with diffuse splenic uptake), while the remaining 12 had no increased splenic uptake. Among patients with FDG-avid lesions, average SUVmax was 4.3, lesion-to-liver SUVmax ratio 2.3, and lesion-to-blood pool SUVmax ratio 3. 18F-FDG avidity was significantly associated with Ki-67 index and not correlated with other features. Semiquantitative PET/CT parameters (SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio) did not correlate significantly with any variable. Progression-free survival time was not influenced by FDG avidity of SMZL.

CONCLUSIONS

18F-FDG avidity was noted in 76% of SMZL with diffuse splenic uptake as main pattern of presentation and is correlated with Ki-67 score only.

Deciphering splenic marginal zone lymphoma pathogenesis: the proposed role of microRNA

Splenic marginal zone lymphoma (SMZL) is a malignancy of mature B-cells that primarily involves the spleen, but can affect peripheral organs as well. Even though SMZL is overall considered an indolent malignancy, the majority of cases will eventually progress to be more aggressive. In recent years, the gene expression profile of SMZL has been characterized in an effort to identify: 1) the etiology of SMZL, 2) biological consequences of SMZL, and 3) putative therapeutic targets. However, due to the vast heterogeneity of the malignancy, no conclusive target(s) have been deciphered. However, the role of miRNA in SMZL, much as it has in chronic lymphocytic leukemia, may serve as a guiding light. As a result, we review the comprehensive expression profiling in SMZL to-date, as well as describe the miRNA (and potential mechanistic roles) that may play a role in SMZL transformation, particularly within the 7q region.

Splenic Primary Follicular Lymphoma With Idiopathic Thrombocytopenic Purpura: Report of a Case

Introduction:

Primary splenic lymphoma is a rare condition that accounts for approximately 1% of non-Hodgkin's lymphoma. No primary splenic follicular lymphoma with idiopathic thrombocytopenic purpura (ITP) has been reported in the literature.

Case presentation:

A 41-year-old man was diagnosed with idiopathic thrombocytopenic purpura (ITP), and received steroid maintenance treatment with oral prednisolone 13 mg/d for 6 years. However, the platelet counts were 20 × 103 /μL or less. Abdominal enhanced computer tomography (CT) revealed splenomegaly. He underwent laparoscopic splenectomy after preoperative high-dose immunoglobulin preparation (30 mg/d intravenously for 5 days) which were effective in the improvement of platelets count (130 × 103 /μL). The histologic diagnosis was B cell type follicular lymphoma of the spleen. Fluorescent in situ hybridization (FISH) revealed a t(14; 18)(q32; q21) translocation, which supported the diagnosis of primary follicular lymphoma of the spleen. After the operation, the patient showed satisfactory recovery, and was discharged on postoperative day 7. He remains well with the platelet count of more than 200 × 103 / μl without medication. We herein report such a case.

Conclusion:

To the best of our knowledge, this is the first reported case of splenic primary follicular lymphoma with ITP.

First-line treatment with bendamustine and rituximab, in patients with intermediate-/high-risk splenic marginal zone lymphomas

Splenic marginal zone lymphomas (SMZLs) are rare indolent B cell neoplasms that affect the spleen, bone marrow, and blood. Although they have an indolent course in the majority of patients, who have a median survival of 8-10 years, ∼ 30% may experience a worse outcome. The prognostic criteria of progression are lymph node and extra-nodal involvement, high lymphocyte counts, anaemia, and thrombocytopenia. The treatment of SMZLs include a "wait and watch strategy", splenectomy, and alkylating agents ± rituximab. We here describe data relating to 70 patients with intermediate-/high-risk SMZLs, who received rituximab/bendamustine as first-line treatment for a median of 60 days (range 1-75) after diagnosis. Sixty patients (86%) achieved a complete response (CR), and seven (10%) a partial response (PR). Three patients (4.3%) experienced disease progression (PD). The median duration of remission was 18 months. Side effects were generally mild. Our findings suggest that rituximab/bendamustine is a feasible treatment option in patients with intermediate-/high-risk SMZLs.

Indolent B-Cell Lymphoid Malignancy in the Spleen of a Man Who Handled Benzene: Splenic Marginal Zone Lymphoma

We present the case of a 45-year-old man with a history of benzene exposure who developed splenic marginal zone lymphoma. For 6 years, he had worked in an enclosed space cleaning instruments with benzene. He was diagnosed with splenic marginal zone lymphoma 19 years after retirement. During his time of working in the laboratory in the 1980s, working environments were not monitored for hazardous materials. We indirectly estimated the cumulative level of past benzene exposure using job-exposure matrices and technical assumptions. Care must be taken in investigating the relevance of occupational benzene exposure in the occurrence of indolent B-cell lymphoma. Because of the long latency period and because occupational measurement data do not exist for the period during the patient's exposure, the epidemiological impact of benzene exposure may be underestimated.

Important Diagnostic Clues for Diagnosing Splenic Marginal Zone Lymphoma in Absence of Splenic Histology

Splenic Marginal Zone Lymphoma (SMZL) is a rare B-cell neoplasm comprising less than 2% of non-Hodgkin lymphomas. We hereby report a case of SMZL in a 66-year-old female who presented with fever and massive splenomegaly. Peripheral blood smear examination showed atypical lymphoid cells showing variable cytoplasmic processes. Flowcytometric immunophenotyping of peripheral blood showed tumour cells which were found to be positive for CD19, CD79b and showing kappa light chain restriction along with lack of expression for CD5, CD10, CD23, CD103 and lambda. These findings were suggestive of B cell chronic lymphoproliferative disorder. Various differential diagnoses considered in this case were analysed by using different diagnostic clues to arrive at the diagnosis. Bone marrow examination and Immunohistochemical (IHC) analysis showed tumour cells in nodular, interstitial and intrasinusoidal pattern of infiltration which were positive for CD20 and CD79b with kappa light chain restriction and lack of expression of CD5, CD10, CD23 and CD103 which further corroborated the flowcytometric immunophenotyping. The diagnosis of SMZL is arrived at by a combination of diagnostic clues like clinical features, peripheral smear findings, flowcytometric immunophenotyping, morphological and IHC findings in bone marrow biopsy. This case highlights the significance of flowcytometric immunophenotyping and bone marrow biopsy with immunohistochemistry to arrive at a diagnosis of SMZL even in absence of splenic histopathology.

High-Grade Transformation in a Splenic Marginal Zone Lymphoma with a Cerebral Manifestation

Patient: Female, 31

Final Diagnosis: Histological transformation of splenic low-grade lymphoma

Symptoms: Fatigue • night sweats

Medication: —

Clinical Procedure: Intravenous methylprednisolone followed by high-dose methotrexate

Specialty: Hematology

Murine Models of Splenic Marginal Zone Lymphoma: A Role for Cav1?

Dozens of murine models of indolent and aggressive B-cell lymphomas have been generated to date. These include those manifesting chronic lymphocytic leukemia (CLL), diffuse large B-cell lymphoma (DLBCL), as well as xenografts of mantle cell lymphoma (MCL). These models have led to an improved understanding of disease etiology, B-cell biology, immunomodulation, and the importance of the tumor microenvironment. Despite these efforts in CLL, DLBCL, and MCL, considerably little progress toward a model of splenic marginal zone lymphoma (SMZL) has been accomplished. Herein, we describe the similarities and differences between CLL, MCL, and SMZL and highlight effective murine models that mimic disease in the two former, in hopes of informing a potential model of the latter. At the time of writing this review, the precise molecular events of SMZL remain to be determined and a treatment regimen remains to be identified. Therefore, based on the efforts put forth in the B-cell lymphoma field throughout the past three decades, the established role of caveolin-1 in B- and T-cell biology as an oncogene or tumor suppressor, and the recurrent deletion or loss of heterozygosity (LOH) of 7q in many cancers, we make recommendations for a murine model of SMZL.

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.

Bendamustine and Rituximab, as First Line Treatment, in Intermediate, High Risk Splenic Marginal Zone Lymphomas of Elderly Patients

Background

Splenic marginal zone lymphoma (SMZL) is a chronic B-cell lymphoproliferative disorder, comprising less than 2% of non-Hodgkin’s lymphomas, and affecting mainly middle-aged and elderly patients with a median survival of >10 years. The typical clinical features of SMZL include splenomegaly. Treatment should be patient-tailored and can range from a ‘watchful waiting’ approach for asymptomatic patients without cytopenias to surgery, localized radiation therapy or immuno/chemotherapies. Recently, the combination of rituximab and Bendamustine (R-Benda) has been defined as highly active in patients with follicular lymphomas, but little is known about the efficacy of R-Benda in SMZL.

Aim of the study

The purpose of this retrospective study was to report our experience on the efficacy of R-Benda as first line treatment in 23 consecutive elderly SMZL patients.

Results

All patients had a complete resolution of splenomegaly along with restoration of their blood counts. Nineteen patients (83%) achieved a complete response (CR) to therapy; three patients (13%) achieved a partial response (PR).Ten patients (43%) obtained molecular remission. Toxicities were mild and mainly haematological and result in dose reductions for fourteen patients.

Conclusions

Our data suggest a high activity and good tolerance of R-Benda, despite dose reduction due to potential toxicity.

A Single-center Experience in Splenic Diffuse Red Pulp Lymphoma Diagnosis

The World Health Organization 2008 classification highlighted a new nosology-splenic diffuse red pulp lymphoma (SDRPL) with clinical and laboratory features similar to both splenic marginal zone lymphoma and hairy cell leukemia (HCL) and variant form of HCL. Experience of hematologists on the diagnosis and differential diagnosis of SDRPL is extremely limited. The aim of our report was to characterize the clinical and immunomorphologic features of SDRPL on our own observations. During 2013-2014, in National Research Center for Hematology, 87 spleen specimens removed from various B-cell lymphomas were analyzed. In four (4.6%) cases, the diagnosis SDRPL was made based on morphologic, immunohistochemical, immunophenotypic, molecular examination of spleen biopsies, blood and bone marrow samples. In all cases of SDRPL were observed significant splenomegaly, lymphocytosis from 56% to 94% (in two cases with leukocytosis 55.000 and 75.000 109/l). The circulating "villous" lymphocytes phenotype was CD20+ (bright), CD11c+/±, CD103 (weakly)+/±, LAIR-1+, CD25-, CD5-, CD10-, and CD23-. Mutation BRAFV600E was not detected. Bone marrow with minor lymphoid CD20+, CD25-, Annexin1-, Cyclin D1- cell infiltration. The average weight of the spleen was 3900 g (1450-9500 g), and morphologically, there was revealed lymphoid infiltration of red pulp with phenotype CD20+, DBA.44+, CD25-, Annexin1-, Cyclin D1-, CD103-, CD123-, CD27-, focal SD11c± and TRAP±. Now patients are observed in remission: two patients after splenectomy, two after splenectomy and cladribine+rituximab chemotherapy. SRDPL-a rare lymphoma that is suspected in the cases with significant splenomegaly and lymphocytosis with villous lymphocytes forms that have only a part of the classic markers HCL, with minor bone marrow infiltration. The standard diagnosis and treatment is splenectomy. Differential diagnosis of SMZL and HCL has clear criteria, but criteria of differentiation with variant HCL are still unknown.

[Experience in investigating splenic red pulp lymphoma]

AIM

To generalize hematologists' experience of the diagnosis and differential diagnosis of splenic red pulp lymphoma (SRPL).

MATERIAL AND METHODS

Eighty-seven splenic biopsy specimens taken from patients with different B-cell lymphoproliferative diseases were examined in the Hematology Research Center in 2013-2014. The diagnosis of SRPL was based on the morphological, immunohistochemical, immunophenotypic, and molecular examinations of the splenic biopsy specimens, blood and bone marrow (BM) tests in 4 (4.6%) cases.

RESULTS

There was significant splenomegaly in all SRPL cases, lymphocytosis in 56 to 94% (leukocytes, 55 and 75·109/l in 2 cases), circulation of hairy lymphocytes with the phenotypes CD20+ (markedly), CD11c+/±, CD103+/± (weakly), LAIR-1+, CD25-, CD5-, CD10-, and CD23-, which did not contain tartate-resistant acid phosphatase, without BRAFV600E mutation, BM with insignificant lymphoid infiltration of CD20+, CD25-, Annexin 1-, and Cyclin D1-. The weight of the spleen averaged 3900 g (1450-9500 g); its tissue exhibited lymphoid infiltration of the red pulp with the phenotypes CD20+, DBA.44+, CD25-, Annexin1-, Cyclin D1-, CD103-, CD123-, CD27-, focal СD11c±, and TRAP±. Four patients (2 after splenectomy (SE) and 2 after SE and chemotherapy with cladribine and rituximab) are being followed up in remission.

CONCLUSION

SRPL is a rare disease that should be presumed to be in significant splenomegaly and lymphocytosis with hairy lymphocytes, which have only some markers for classical hairy cell leukemia (HCL), in minor BM lesion. SE is the standard for diagnosis and treatment. The differential diagnosis of SRPL with HCL has clear criteria and that with HCL-v is undetected.

[Molecular analysis of immunoglobulin genes in the tumor B cells in splenic marginal zone lymphoma]

AIM

To determine the immunoglobulin variable heavy chain (gVH) genes and their somatic mutations and to compare these data with the clinical and laboratory parameters of patients and the outcomes of the disease.

SUBJECTS AND METHODS

The investigation enrolled 24 patients (9 men and 15 women whose age was 32 to 77 years (median age, 60 years) with splenic marginal zone B-cell lymphoma (SMZBCL). The latter was diagnosed on the basis of histological and immunohistochemical examinations of a bone marrow trephine biopsy specimen, immunophenotyping of peripheral lymphoid cells or bone marrow aspirates.

RESULTS

The mutational status of the IgVH genes was analyzed in all the 24 patients. It was found that the tumor cells contained mutated IgVH genes (the VH1-family genes participated in most cases) in 15 (62.5%) patients with SMZBCL and unmutated ones in 9 (37.5%). There was a tendency towards more common tumor progression in patients with unmutated IgVH genes than in those with mutated ones.

CONCLUSION

The presence of SMZBCL cases with both mutated and unmutated IgVH genes and the higher frequency of the VH1-2 gene are likely to indicate the molecular heterogeneity of the origin of this lymphoma.

Remission of splenic marginal zone lymphoma in a patient treated for hepatitis B: a case of HBV-associated lymphoma

Splenomegaly is a common finding in chronic hepatitis B infection. We present the case of a man with an acute flare of chronic hepatitis B infection, where splenomegaly in absence of portal hypertension led to the diagnosis of splenic marginal zone lymphoma (SMZL) with bone marrow involvement. Adequate suppression of the hepatitis B virus (HBV) viral load with tenofovir resulted in complete remission of the lymphoma.

The human microbiome in hematopoiesis and hematologic disorders

Humans are now understood to be in complex symbiosis with a diverse ecosystem of microbial organisms, including bacteria, viruses, and fungi. Efforts to characterize the role of these microorganisms, commonly referred as the microbiota, in human health have sought to answer the fundamental questions of what organisms are present, how are they functioning to interact with human cells, and by what mechanism are these interactions occurring. In this review, we describe recent efforts to describe the microbiota in healthy and diseased individuals, summarize the role of various molecular technologies (ranging from 16S ribosomal RNA to shotgun metagenomic sequencing) in enumerating the community structure of the microbiota, and explore known interactions between the microbiota and humans, with a focus on the microbiota's role in hematopoiesis and hematologic diseases.

Role of blood and bone marrow examination in the diagnosis of mature lymphoid neoplasms in patients presenting with isolated splenomegaly

OBJECTIVES

Mature lymphoid neoplasms presenting with 'prominent splenomegaly without significant lymphadenopathy' are uncommon and pose unique diagnostic challenges as compared to those associated with lymphadenopathy. Their descriptions in the literature are largely limited to a few case series. We analyzed the spectrum of these lymphomas diagnosed by peripheral blood (PB) and/or bone marrow (BM) examination.

METHODS

Over a period of 6 years, 75 patients were diagnosed with a lymphoma from PB/BM who had presented with predominant splenomegaly. Their clinical and laboratory records including PB and BM morphology; immunophenotyping using multi-parametric flow-cytometry and immunohistochemistry were reviewed. Wherever indicated, an extended panel of immunohistochemistry (IHC) was performed on BM biopsies for accurate sub-classification.

RESULTS AND DISCUSSION

The commonest lymphomas were hairy cell leukemia (HCL) (32%) and splenic marginal zone lymphoma (SMZL) (24%). Others included diffuse large B cell lymphoma (8%), chronic lymphocytic leukemia/small lymphocytic lymphoma (8%), mantle cell lymphoma (2.7%), and follicular lymphoma (1.3%), all of which usually presents with lymphadenopathy. SMZL was the commonest lymphoma among females and those with massive splenomegaly and lymphocytosis; while HCL was commonest in patients with pancytopenia. SMZL commonly presented with lymphocytosis; however, 22% of them also presented with pancytopenia.

CONCLUSION

The high diagnostic efficacy of PB and BM examination using flow-cytometry and immunohistochemistry in confirming and sub-classifying splenic lymphomas suggests that a thorough hematological evaluation should always precede a diagnostic splenectomy. Immunohistochemistry remains the best modality to identify sparse or intra-sinusoidal infiltration on BM biopsy and is particularly useful in patients with fibrotic marrows and pancytopenia.

Management of the marginal zone lymphomas

Marginal zone lymphomas (MZL) represent around 8 % of all non-Hodgkin lymphomas. During the last decades a number of studies have addressed the mechanisms underlying the disease development. Extranodal MZL lymphoma usually arises in mucosal sites where lymphocytes are not normally present from a background of either autoimmune processes, such as Hashimoto thyroiditis or Sjögren syndrome or chronic infectious conditions. In the context of a persistent antigenic stimulation, successive genetic abnormalities can progressively hit a B-cell clone among the reactive B-cells of the chronic inflammatory tissue and give rise to a MALT lymphoma. The best evidence of an etiopathogenetic link is available for the association between Helicobacter pylori-positive gastritis and gastric MALT lymphoma. Indeed, a successful eradication of this micro-organism with antibiotics can be followed by gastric MALT lymphoma regression in more than 2/3 of cases. Other microbial agents have been implicated in the pathogenesis of MZL arising in the skin (Borrelia burgdorferi), in the ocular adnexa (Chlamydophila psittaci), and in the small intestine (Campylobacter jejuni). The prevalence of hepatitis C virus (HCV) has also been reported higher in MZL patients (particularly of the splenic type) than in the control population, suggesting a possible causative role of the virus. In non-gastric MALT lymphoma and in splenic MZL the role of the antimicrobial therapy is, however, less clear. This review summarizes the recent advances in Marginal Zone Lymphomas, addressing the critical points in their diagnosis, staging and clinical management.

A rare case of splenic marginal zone B-cell lymphoma mimicking relapsing polychondritis of the ear

Relapsing polychondritis (RPC) is a poorly understood phenomenon associated with cartilaginous inflammation of the ear, nose, tracheobronchial tree, and peripheral joints. Many cases of RPC respond to anti-inflammatories and resolve with no further complications. However, RPC has also been linked to more insidious conditions such as malignancies, autoimmune disorders, vasculitis, or underlying infections. Given the spectrum of associated disorders, patients with RPC may need to be monitored for more insidious underlying conditions. In this case, we report a unique case of bilateral auricular inflammation and nasal inflammation mimicking RPC as the only presenting symptom of splenic marginal zone B-cell lymphoma and we survey related cases in the literature.

Disease-specific mutations in mature lymphoid neoplasms: recent advances

Mature lymphoid neoplasms (MLN) are clinically and pathologically more complex than precursor lymphoid neoplasms. Until recently, molecular characterization of MLN was mainly based on cytogenetics/fluorescence in situ hybridization, allele copy number, and mRNA expression, approaches that yielded scanty gene mutation information. Use of massive parallel sequencing technologies has changed this outcome, and now many gene mutations have been discovered. Some of these are considerably frequent in, and substantially specific to, distinct MLN subtypes, and occur at single or several hotspots. They include the V600E BRAF mutation in hairy cell leukemia, the L265P MYD88 mutation in Waldenström macroglobulinemia, the G17V RHOA mutation in angioimmunoblastic T-cell lymphoma and peripheral T-cell lymphoma, not otherwise specified, and the Y640F//D661Y/V/H/I//N647I STAT3 mutations in T-cell large granular lymphocytic leukemia. Detecting these mutations is highly valuable in diagnosing MLN subtypes. Defining these mutations also sheds light on the molecular pathogenesis of MLN, furthering development of molecular targeting therapies. In this review, we focus on the disease-specific gene mutations in MLN discovered by recent massive sequencing technologies.

Bone marrow stroma CD40 expression correlates with inflammatory mast cell infiltration and disease progression in splenic marginal zone lymphoma

In SMZL, the quality of BM stromal microenvironment predicts disease progression. CD40-CD40L-mediated interactions between mast cells and BM mesenchymal cells engender proinflammatory conditions within SMZL infiltrates.

Challenges and new prospects in hepatosplenic γδ T-cell lymphoma

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of lymphoid neoplasms characterized by aggressive clinical behavior and dismal prognosis. Hepatosplenic γδ T-cell lymphoma (γδ-HSTL) is a particular form of PTCL that arises from a small subset of γ/δ T-cell receptor-expressing lymphocytes. γδ-HSTL has a rapidly progressive course and poor outcome due also to its refractoriness to conventional chemotherapy regimens. The very low incidence of γδ-HSTL, along with its propensity to mimic different pathological entities, makes this lymphoma a true diagnostic challenge. In this review, we highlight the biological and clinical features of γδ-HSTL that contribute to making this lymphoma a mostly incurable disease. Moreover, we provide a new insight into the crosstalk between HSTL clones and the bone marrow, liver and spleen vascular microenvironment, in which neoplastic cells reside and proliferate. We further discuss γδ-HSTL associated molecules that might be proposed as potential targets for novel therapeutic approaches.

Osteosarcoma: mouse models, cell of origin and cancer stem cell

Osteosarcoma (OS) is the most common non-hematologic primary tumor of bone in children and adults. High-dose cytotoxic chemotherapy and surgical resection have improved prognosis, with long-term survival for non-metastatic disease approaching 70%. However, most OS tumors are high grade and tend to rapidly develop pulmonary metastases. Despite clinical advances, patients with metastatic disease or relapse have a poor prognosis. Here the cell biology of OS is reviewed with a special emphasis on mouse models as well as the roles of the cell of origin and cancer stem cells. A better understanding of the molecular pathogenesis of human OS is essential for the development of improved prognostic and diagnostic markers as well as targeted therapies for both primary and metastatic OS.

Splenectomy for massive splenomegaly: long-term results and risks for mortality

OBJECTIVE

To evaluate long-term outcomes after splenectomy for massive splenomegaly in a series of 222 consecutive patients.

BACKGROUND

Splenectomy for massive splenomegaly (>1500 g) provides palliation but is associated with a high rate of perioperative complications in a population of patients with advanced hematological malignancies. Predictive factors for survival and whether the palliative goals are achieved in the long-term are not well defined.

METHODS

Patients with various hematological disorders who underwent splenectomy between 1998 and 2009 were followed until death or for at least 2 years. Linear and logistic regression analyses were used to ascertain the impact of demographical factors, diagnoses, and preoperative transfusion parameters on the postoperative survival.

RESULTS

Splenectomy for massive splenomegaly was performed most commonly for non-Hodgkin lymphoma (48%) and myeloid metaplasia (31%). Mean ± standard deviation splenic weight was 2731 ± 1393 g (range, 1500-13,085 g). Average operating time was 115 minutes, with a range from 46 to 346 minutes. Thirty-day mortality was 1.8%, and the complication rate was 20%. The most common complications were hemorrhage (9%) and portal venous thrombosis (9.9%). Relief from pressure-related symptoms was achieved in 98.5%, and durable remission of anemia and thrombocytopenia persisted in half of the patients at 2 years. Sex, age, and intraoperative blood loss were not significantly associated with survival. Preoperative need for red blood cell and platelet transfusions were the most significant risk factors associated with decreased survival.

CONCLUSIONS

Splenectomy for massive splenomegaly can be performed safely and offers durable palliation. Preoperative transfusion requirement is an indicator of hematological disease severity and predictor of decreased survival.

[Successful treatment with rituximab in a patient with splenic marginal zone B-cell lymphoma accompanied by cold agglutinin disease]

An 81-year-old man was admitted to our hospital due to dyspnea in July 2008. A physical examination revealed marked splenomegaly, and the results of laboratory tests were as follows: hemoglobin (Hb)=7.0 g/dL, Ret=6.4%, WBC=24,100/μL (Ly: 20,003/μL), indirect bilirubin=3.6 mg/dL, LDH=232 IU/L. The cold agglutinin titer was 1 : 8,192, and a direct antiglobulin test was positive. A PET scan showed abnormal accumulation in the spleen and bone marrow. A bone marrow aspirate examination and biopsy demonstrated diffuse involvement of abnormal lymphocytes that were found to be positive for CD20 and negative for CD5, CD10, and cyclin D1. The immunoglobulin genes were clonally rearranged. Based on these findings, splenic marginal zone B-cell lymphoma (SMZL) associated with cold agglutinin disease (CAD) was diagnosed. Because the patient refused splenectomy, he was treated with four cycles of rituximab therapy (375 mg/kg, once a week). The Hb level and lymphocyte count subsequently normalized and the splenomegaly resolved. One year later, he relapsed and was again treated with rituximab therapy with complete remission. CAD accompanied by SMZL is very rare. Rituximab may be chosen as an alternative and effective therapeutic option in patients with SMZL-particularly those with autoimmune hemolytic anemia.

Comparative outcomes of rituximab-based systemic therapy and splenectomy in splenic marginal zone lymphoma

Despite diagnostic and therapeutic advances, the majority of patients with splenic marginal zone lymphoma (SMZL) are still treated with splenectomy. We analyzed survival outcomes after surgery or rituximab-based systemic therapy in the Surveillance Epidemiology and End Results-Medicare database, using inverse probability of treatment weighting to minimize treatment selection bias. From the 657 recorded cases diagnosed between 2000 and 2007, with a median age of 77 years, we selected 227 eligible patients treated with splenectomy (68 %), rituximab alone (23 %), or in combination with chemotherapy (9 %) within 2 years from diagnosis. No significant difference between the groups was observed in the cumulative incidence of lymphoma-related death (LRD) at 3 years (19.6 % with systemic therapy and 17.3 % with splenectomy; hazard ratio [HR], 1.04; 95 % confidence interval [CI], 0.56-1.92; P = 0.90) or in the overall survival (HR, 1.01; 95 % CI, 0.66-1.55; P = 0.95). The 90-day mortality after splenectomy was 7.1 %. The rates of hospitalizations, infections, transfusions, and cardiovascular or thromboembolic events were higher after combination chemoimmunotherapy than after splenectomy. Conversely, there was no significant difference in most complications between groups treated with splenectomy or rituximab alone. The cumulative incidence of LRD after single-agent rituximab at 3 years was 18.7 % (95 % CI, 8.6-31.7). In conclusion, in SMZL patients over the age of 65 years, the risk of LRD and overall survival are similar with systemic therapy or splenectomy as initial therapy. Single-agent rituximab may offer the most favorable risk/benefit ratio in this population.

ESMO Consensus conferences: guidelines on malignant lymphoma. part 2: marginal zone lymphoma, mantle cell lymphoma, peripheral T-cell lymphoma

To complement the existing treatment guidelines for all tumour types, ESMO organizes consensus conferences to focus on specific issues in each type of tumour. In this setting, a consensus conference on the management of lymphoma was held on 18 June 2011 in Lugano, next to the 11th International Conference on Malignant Lymphoma. The conference convened ∼30 experts from all around Europe, and selected six lymphoma entities to be addressed; for each of them, three to five open questions were to be addressed by the experts. For each question, a recommendation should be given by the panel, referring to the strength of the recommendation based on the level of evidence. This consensus report focuses on the three less common lymphoproliferative malignancies: marginal zone lymphoma, mantle cell lymphoma, and peripheral T-cell lymphomas. A first report had focused on diffuse large B-cell lymphoma, follicular lymphoma, and chronic lymphocytic leukaemia.

Viral latency locus augments B-cell response in vivo to induce chronic marginal zone enlargement, plasma cell hyperplasia, and lymphoma

Kaposi sarcoma (KS) is associated with KS-associated herpesvirus (KSHV). This virus also causes B-cell lymphoma and B-cell hyperplasia. There exists no in vivo model for KSHV-associated B-cell malignancies or premalignant persistence in B cells. We generated a transgenic mouse that expresses multiple viral latent genes, including LANA, vFLIP, vCYC, all viral micro RNAs, and kaposin under the transcriptional control of their natural regulatory region. This promoter is B-cell specific, though it is a weak promoter. Mature B cells were chronically activated, leading to hyperglobulinemia triggered by increased plasma cell frequency and marginal zone (MZ) B-cell hyperplasia. The mice had an augmented response to T-dependent antigen as well as the TLR4 ligand LPS, leading to exacerbated MZ and germinal center responses and increased CD138(+) plasma cells. It is the first model to assess the viral micro RNA function in vivo. These data support a potentially novel mechanism of viral persistence in which virally infected B cells become hyper-responsive to coincident, but unrelated, pathogen exposure, leading to preferential expansion and ultimately lymphoma in a small subset of cases.

Treatment of splenic marginal zone lymphoma with rituximab monotherapy: progress report and comparison with splenectomy

BACKGROUND

Treatment of splenic marginal zone lymphoma (SMZL) patients is not standardized. Recent data suggest that rituximab is highly effective and could be considered as initial therapy.

AIM

To assess the efficacy of rituximab monotherapy in a large series of patients with SMZL and compare these results with splenectomy results.

METHODS

The studied population included 85 patients. Fifty-eight received rituximab at a dose of 375 mg/m2 per week for 6 weeks as induction followed by maintenance at the same dose every 2 months for 1-2 years, whereas 27 patients were treated using splenectomy only.

RESULTS

The overall response rate to rituximab 2 months after the end of induction was 95% (complete response [CR], 45%; unconfirmed CR, 26%; partial response, 24%). The median times to hematologic and clinical response were 2 weeks and 3 weeks, respectively. Forty-three of 55 patients already completed the maintenance phase: 28 sustained their initial response, 14 improved their response, and one progressed. Eighty-five percent of splenectomized patients responded, and two were treated with rituximab as consolidation after splenectomy and achieved a CR. The 5-year overall and progression-free survival (PFS) rates for rituximab-treated and splenectomized patients were 92% and 77% (p = .09) and 73% and 58% (p = .06), respectively. Furthermore, maintenance therapy with rituximab resulted in a longer duration of response (at 5 years, PFS was 84% for patients receiving maintenance and 36% for patients without maintenance, p <.0001).

CONCLUSIONS

Rituximab is a very effective and well-tolerated therapy and may be substituted for splenectomy as the first-line treatment of choice for patients with SMZL.

Treatment of splenic marginal zone lymphoma of the CNS with high-dose therapy and allogeneic stem cell transplantation

Therapy of indolent lymphomas with involvement of the central nervous system (CNS) has not been standardized so far. A 42-year old male patient presented with neurological signs because of leukemic splenic marginal zone lymphoma (SMZL) manifested in bone marrow, lymph nodes and CNS. Due to the aggressiveness of the disease and the young age of the patient, an intensive immunochemotherapy followed by high-dose therapy with busulfan, thiotepa and fludarabine and subsequent unrelated allogeneic stem cell transplantation (alloSCT) was performed. The haemopoietic stem cells engrafted in time and the patient is doing well (ECOG 0) without evidence for active lymphoma three years after transplantation. Highly sensitive tests by specific quantitative real-time polymerase chain reaction for presence of lymphoma cells in blood and bone marrow indicated also a molecular remission. The reported case shows the feasibility of high-dose therapy and allogeneic stem cell transplantation in high-risk patients with CNS-involvement of indolent non-Hodgkin’s lymphoma. In addition, the case supports the hypothesis that the graft-versus lymphoma effect after alloSCT is also active within the CNS.

Marginal zone lymphoma: old, new, targeted, and epigenetic therapies

Marginal zone lymphoma (MZL) is an indolent B-cell lymphoma arising from marginal zone B-cells present in lymph nodes and extranodal tissues. MZL comprises 5-17% of all non-Hodgkin's lymphomas in adults. The World Health Organization categorizes MZL into three distinct types based on their site of impact: (1) splenic marginal zone lymphoma (SMZL); (2) nodal marginal zone lymphoma (NMZL); (3) extranodal mucosa-associated lymphoid tissue (MALT) lymphoma, which can be subdivided into gastric and nongastric. The subgroups of MZL share some common features but are different in their biology and behavior. Owing to the rarity of MZL there are few randomized trials available comparing various treatment options and therefore treatment is controversial, lacking standard guidelines. Treatment should be patient tailored and can range from a 'watchful waiting' approach for asymptomatic patients without cytopenias to surgery or localized radiation therapy. Rituximab in combination with chemotherapy has resulted in longer failure-free survival than chemotherapy alone in patients with SMZL. Helicobacter pylori positive gastric MALT shows a good response rate to triple antibiotic therapy. Newer therapies such as bendamustine, everolimus, lenalidomide, vorinostat and phosphoinositide 3-kinase inhibitors are in clinical trials for patients with relapsed or refractory MZL and have shown promising results. We are presently conducting clinical trials testing the efficacy of the epigenetic activity of cladribine as a hypomethylating agent in combination with the histone deacetylase inhibitor (HDACi) vorinostat and rituximab in patients with MZL. Further studies with the newer agents should be done both in newly diagnosed or relapsed/refractory MZL to streamline the care and to avoid the use of toxic chemotherapies as initial treatment.

The utility of immunohistochemistry for the identification of hematopoietic and lymphoid cells in normal tissues and interpretation of proliferative and inflammatory lesions of mice and rats

Expression of antigens in cells and tissues can be readily studied immunohistochemically with the use of antibodies. A panel of antibodies to cell-specific markers can be used to diagnose lesions, including tumors, in the hematopoietic and lymphoid systems. This review discusses the use of readily available antibodies and procedures to identify antigens expressed in normal tissues and in proliferative and inflammatory lesions in formalin-fixed, paraffin-embedded (FFPE) murine specimens.