Splenic marginal zone lymphoma: a literature review of diagnostic and therapeutic challenges

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.

Marginal zone lymphoma with severe rashes: A case report

BACKGROUND

Marginal zone lymphoma (MZL) is an indolent subtype of non-Hodgkin lymphoma (NHL), which is rare clinically with severe rashes as the initial symptom.

CASE SUMMARY

This study reports a case of MZL with generalized skin rashes accompanied by pruritus and purulent discharge. First-line treatment with rituximab combined with zanubrutinib had poor effects. However, after switching to obinutuzumab combined with zanubrutinib, the case was alleviated, and the rashes disappeared.

CONCLUSION

For patients with advanced stage MZL not benefiting from type I anti-CD20 monoclonal antibody (mAb) combination therapy, switching to a type II anti-CD20 mAb combination regimen may be considered. This approach may provide a new perspective in the treatment of MZL.

Marginal zone lymphoma: 2023 update on diagnosis and management

DISEASE OVERVIEW

Marginal zone lymphomas (MZL) are collectively the second most common type of indolent lymphoma.

DIAGNOSIS

Three subtypes of MZL are recognized: splenic, extranodal, and nodal. The diagnosis is secured following biopsy of an involved nodal or extranodal site demonstrating a clonal B-cell infiltrate with CD5 and CD10 negative immunophenotype most common. Some cases will features IgM paraprotein, but MYD88 L256P mutations are less frequent than in Waldenstrom macroglobulinemia. Prognostication Several prognostic models have been developed, including the MALT-IPI and the MZL-IPI. The latter is broadly applicable across MZL subtypes and incorporates elevated serum LDH, anemia, lymphopenia, thrombocytopenia and nodal or disseminated subtypes as independent predictors of outcome.

TREATMENT

We discuss suggested approach to therapy for both early and advanced-stage disease, with reference to chemo-immunotherapy, radiotherapy, and emerging treatments in relapsed/refractory disease such as BTK inhibitors.

Splenic Lymphomas: A Tertiary Care Center Experience and Review of Literature

Primary splenic lymphomas are rare with the majority of lymphomas in spleen being secondary to an extra-splenic lymphoma. We aimed to analyze the epidemiological profile of the splenic lymphoma and review the literature. This was a retrospective study including all splenectomies and splenic biopsies from 2015 to September 2021. All the cases were retrieved from Department of Pathology. Detailed histopathological, clinical and demographic evaluation was done. All the lymphomas were classified according to WHO 2016 classification. A total of 714 splenectomies were performed for a variety of benign causes, as part of tumor resections and for the diagnosis of lymphoma. Few core biopsies were also included. A total of 33 lymphomas diagnosed in the spleen, primary splenic lymphomas constituted 84.84% (n = 28) of the cohort with 5 (15.15%) having the primary site elsewhere. The primary splenic lymphomas constituted 0.28% of all the lymphomas arising at various sites. Adult population (19-65 years) formed the bulk (78.78%) with a slight male preponderance. Splenic marginal zone lymphomas (n = 15, 45.45%) comprised of major proportion of cases followed by primary splenic diffuse large B-cell lymphoma (n = 4, 12.12%). Splenectomy was the main course of treatment for SMZL with a good overall outcome, with chemotherapy ± radiotherapy forming the mainstay in other lymphomas. Lymphomas in spleen can be infiltrative or a primary, hence proper clinic-radiological and pathological evaluation is required. Appropriate management is guided by the precise and detailed evaluation by the pathologist, requiring understanding of the same.

Concurrent Splenic Marginal Zone B Cell Lymphoma and Metastatic Pancreatic Adenocarcinoma Diagnosed on Splenectomy for Suspected Splenic Abscess

Splenic marginal zone lymphoma (SMZL) is an uncommon low-grade B-cell lymphoma. It is an indolent lymphoma with a median survival rate of greater than 10 years. Most patients are asymptomatic, but some patients may present with upper abdominal pain and distention, while others may present with splenomegaly, emaciation, fatigue, or weight loss. Due to the long median survival, patients with SMZL may develop a second primary malignancy. Pancreatic adenocarcinoma is the most common malignant neoplasm of the pancreas. It has a poor prognosis with a five-year survival rate of 10%. Fifty percent of patients have metastatic disease on presentation. However, the spleen is not a common site of metastasis for malignant tumors from other primary sites including the pancreas. Here we present a case of a 78-year-old African American patient, who was found to have previously undiagnosed, concurrent metastatic pancreatic adenocarcinoma and SMZL diagnosed on splenectomy for a suspected splenic abscess.

Management of Marginal Zone Lymphoma: A Canadian Perspective

Marginal zone lymphomas (MZL) are a rare, heterogenous group of lymphomas, accounting for 5-17% of indolent non-Hodgkin lymphomas in the western world. They can be further divided into three subtypes: extranodal MZL, splenic MZL, and nodal MZL. These subtypes differ in clinical presentation and behavior, which influences how they are managed. There is currently no standard of care for the treatment of MZL, owing to the difficulty in conducting phase 3 randomized trials in MZL, and the fact that there are limited data on the efficacy of therapy in individual subtypes. Treatment practices are thus largely borrowed from other indolent lymphomas and are based on patient and disease characteristics, as well as access to therapy. This review summarizes the Canadian treatment landscape for MZL and how these therapies may be sequenced in practice.

Incidental Splenic Marginal Zone Lymphoma With Extreme Macrocytosis After Hydroxyurea Use: A Case Report

Splenic marginal zone lymphoma (SMZL) is a low-grade mature B-cell lymphoma that typically presents in the form of splenomegaly and lymphocytosis. The diagnosis is traditionally made through splenic histology, the presence of circulating villous lymphocytes, or bone marrow biopsy. Its treatment can be in the form of chemotherapy, such as rituximab, or active surveillance. This case presentation discusses a 76-year-old female with a long history of hydroxyurea use for an unknown reason presenting with atypical symptoms requiring bone marrow biopsy to diagnose SMZL. This unique case demonstrates the importance of further research and studies into atypical SMZL presentations and hydroxyurea's potential in precipitating secondary malignancies.

The Diagnostic Dilemma of Splenic Non-Hodgkin's Lymphoma and Splenic Abscess: A Narrative Review

Non-Hodgkin's lymphoma (NHL) is a lymphoproliferative disorder that principally displays lymph node involvement but can also spread to extranodal sites such as the spleen. Primary splenic NHL arises in the spleen and, due to its atypical presentation, can sometimes present similarly to other splenic conditions. This review aims to highlight how primary splenic NHL can be effectively differentiated from other splenic conditions, such as splenic abscesses. PubMed, MEDLINE, Scopus, Google, and Google Scholar were used to identify articles mainly focused on splenic non-Hodgkin's lymphoma and splenic abscess. The search was limited to articles published from January 2005 to November 2022. Of the 229 total articles amassed, only 34 were selected and narratively reviewed. From a thorough review of the current literature, it is evident that splenic NHL displays a similar clinical picture to other splenic conditions, namely splenic abscesses. One cannot easily differentiate between the two conditions, both clinically and via diagnostic imaging. Lymphadenopathy, a hallmark sign of nodal NHL, may or may not be present in splenic NHL. Ultimately, splenectomy with biopsy and immunohistochemical staining (IHC) may be required to confirm the diagnosis. In cases of suspected splenic NHL or splenic abscess with little-to-no symptomatic improvement after medication administration, splenectomy followed by histopathological examination may be required for a definitive diagnosis and proper treatment.

Characterization of spleen and lymph node cell types via CITE-seq and machine learning methods

The spleen and lymph nodes are important functional organs for human immune system. The identification of cell types for spleen and lymph nodes is helpful for understanding the mechanism of immune system. However, the cell types of spleen and lymph are highly diverse in the human body. Therefore, in this study, we employed a series of machine learning algorithms to computationally analyze the cell types of spleen and lymph based on single-cell CITE-seq sequencing data. A total of 28,211 cell data (training vs. test = 14,435 vs. 13,776) involving 24 cell types were collected for this study. For the training dataset, it was analyzed by Boruta and minimum redundancy maximum relevance (mRMR) one by one, resulting in an mRMR feature list. This list was fed into the incremental feature selection (IFS) method, incorporating four classification algorithms (deep forest, random forest, K-nearest neighbor, and decision tree). Some essential features were discovered and the deep forest with its optimal features achieved the best performance. A group of related proteins (CD4, TCRb, CD103, CD43, and CD23) and genes (Nkg7 and Thy1) contributing to the classification of spleen and lymph nodes cell types were analyzed. Furthermore, the classification rules yielded by decision tree were also provided and analyzed. Above findings may provide helpful information for deepening our understanding on the diversity of cell types.

Refractory Splenic Marginal Zone Lymphoma Responsive to Combination Venetoclax and Bortezomib (Velcade) (V2) Therapy

Standard treatment regimens for the management of patients with refractory splenic marginal zone lymphoma (SMZL) are currently unavailable. Here, we report a case of SMZL, which, after failing multiple therapeutics, demonstrated an impressive clinical response to combined Venetoclax and Velcade (V²), a treatment combination currently being investigated in the setting of refractory multiple myeloma. We also report a unique histopathology and mutational profile that may have important implications for the characterization and prognosis of SMZL.

Massive splenomegaly requiring differential diagnosis of hematologic malignancies

An 85-year-old woman presented with pain and a palpable mass in her left flank. Abdominal computed tomography revealed massive splenomegaly and para-aortic lymphadenopathies. Bone marrow biopsy showed CD79a, CD20, and bcl-2-positive atypical lymphocytes, which led to the diagnosis of splenic marginal zone lymphoma.

Advances in the Treatment of Hairy Cell Leukemia Variant

OPINION STATEMENT

Hairy cell leukemia variant (HCL-V) is a rare B cell lymphoproliferative disorder with a clinical-pathological distinction from the classic form of hairy cell leukemia (HCL-C). HCL-V is more aggressive in nature, has a higher tendency to be refractory to conventional purine analog pharmacotherapies, and leads to a poorer prognosis. Hence, these differing features bring paramount importance to the diagnosis and management of HCL-V. While there is no genetic mutation diagnostic of HCL-V, genetic profiling efforts have identified potential therapeutic targets (i.e., MAP2K1, KDM6A, CREBBP, ARID1A, CCND3, U2AF1, KMT2C) and yielded prognostic markers (i.e., IGHV4-34 rearrangements). To date, combination chemoimmunotherapies, such as cladribine and rituximab, have shown the best results in HCL-V. Future directions include targeted therapies such as moxetumomab pasudotox, ibrutinib, trametinib, and binimetinib and potentially anti-CD22 chimeric antigen receptor T cell therapy. The purpose of this review is to provide an outline of the diagnostic approach and an update on the therapeutic advancements in HCL-V.

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.

Abdominal extranodal lymphoma detection: positron emission tomography/computed tomography can help

Background

Lymphoid neoplasms that present with masses are broadly referred to as lymphomas, and they can be classified to two main groups: Hodgkin’s (HL) and non-Hodgkin’s lymphoma (NHL); they are mainly characterized by enlargement of lymph nodes (nodal disease) although any organ in the body can be involved in different settings of the disease (extranodal disease). Adequate staging, which has a direct impact on prognosis, is essential to properly plan therapy. Stage IV disease with extranodal dissemination should be treated by long-term systemic chemotherapy.

By adding the metabolic changes to the conventional CT morphologic changes, combined positron emission tomography (PET) and computed tomography (CT) may offer clinically useful addition in staging of lymphomas and detection of extranodal lesions.

Results

The study included thirty nine patients, with forty-eight extranodal sites with lymphomatous infiltration, twenty-four males (61.5%), and fifteen females (38.4%). The patients showed forty-eight extranodal abdominal lymphomatous infiltration.

The study included twelve gastric lymphomatous lesions (25%), twelve splenic lymphomatous lesion (25%), three ileo-caecal lymphomatous lesions (6.25%), three patients (6.25%) with skin infiltration, three adrenal lymphomatous lesions (6.25%), three patients with hepatic lymphoma, and twelve bone marrow infiltrations (25%).

The most accurate SUV max cutoff value among studied cases was 3.5, the highest SUV max value noted was 21 in gastric lesions, and the lowest SUV max noted was 4.1 in adrenal lesions.

Confirmation of PET/CT results was done by histopathological assessment and post-management follow-up.

Conclusion

PET/CT study is an effective tool for evaluation of extranodal lymphomas. PET/CT fusion images can affect the clinical management plan by detection of extranodal lymphomas with lymphoma staging modification.

Notch dimerization and gene dosage are important for normal heart development, intestinal stem cell maintenance, and splenic marginal zone B-cell homeostasis during mite infestation

Cooperative DNA binding is a key feature of transcriptional regulation. Here we examined the role of cooperativity in Notch signaling by CRISPR-mediated engineering of mice in which neither Notch1 nor Notch2 can homo- or heterodimerize, essential for cooperative binding to sequence-paired sites (SPS) located near many Notch-regulated genes. Although most known Notch-dependent phenotypes were unaffected in Notch1/2 dimer-deficient mice, a subset of tissues proved highly sensitive to loss of cooperativity. These phenotypes include heart development, compromised viability in combination with low gene dose, and the gut, developing ulcerative colitis in response to 1% dextran sulfate sodium (DSS). The most striking phenotypes-gender imbalance and splenic marginal zone B-cell lymphoma-emerged in combination with gene dose reduction or when challenged by chronic fur mite infestation. This study highlights the role of the environment in malignancy and colitis and is consistent with Notch-dependent anti-parasite immune responses being compromised in Notch dimer-deficient animals.

Guillain-Barre Syndrome and Syndrome of Inappropriate Antidiuretic Hormone (SIADH) Secretion as Paraneoplastic Syndromes in Splenic Marginal B-cell Non-Hodgkins Lymphoma: A Rare Presentation

Splenic marginal zone lymphoma (SMZL), a rare sub-type of non-Hodgkin lymphoma (NHL) presents with abdominal discomfort, lymphocytosis, cytopenias along with B symptoms including fatigue, night sweats, night fevers, weight loss. NHLs rarely present with paraneoplastic neurological syndromes like Guillain-Barre (GB) syndrome, myelopathy causing paraplegia, chorea, neuromyotonia, vasculitic neuropathy and dermatomyositis. Here, we present a 85-year old caucasian lady presenting with GB syndrome and Syndrome of Inappropriate Antidiuretic Hormone (SIADH) who eventually got diagnosed with SMZL.

Risk adapted approach: How to treat splenic marginal zone lymphoma in resource-poor settings? - The real-life experience of a Brazilian cancer treatment center

Background

Splenic marginal zone lymphoma (SMZL) is a rare lymphoid B-cell malignant neoplasm with primary involvement of the spleen. It is a chronic disease, of indolent behavior and prolonged survival. However, 25% of cases have higher biological aggressiveness, propensity for histological transformation to high grade B-cell non-Hodgkin lymphoma and shortened survival. Recognition of these cases of reserved outcome is important for selecting a risk-adapted therapeutic approach in a resource-poor settings.

Methods

We described clinical and epidemiological characteristics, survival analysis and prognostic factors in a retrospective cohort of 39 SMZL patients, treated in Latin America.

Results

We observed a predominance of female (71.8%), median age of 63 years and higher incidence of B symptoms (56.4%) and extra-splenic involvement (87.1%) than in European and North-American series. With a median follow-up of 8.7 years (0.6-20.2 years), estimated 5-year overall survival (OS) and progression-free survival (PFS) were 76.9% and 63.7%, respectively. Factors with adverse prognostic impact on OS and PFS were Hb < 100 g/L, platelet count < 100 x 10⁹/L, albumin < 3.5 g/dL, LDH > 480 U/L and high-risk Arcaini and SMZL/WG scores. Despite a relative low number of patients, no superiority was observed among the therapeutic regimens used including rituximab monotherapy, splenectomy and cytotoxic chemotherapy.

Conclusion

Therefore, in resource-poor settings, where access to immunotherapy is not universal for all SMZL patients, we suggest that first-line should consist on rituximab therapy for elderly patients or with high surgical risk or with at least 1 risk factor identified in our study. Remainders can be safely managed with splenectomy.

Putative role of marginal zone B cells in pathophysiological processes

The maintenance of inner integrity of an organism is founded on the proper performance of two immunity branches, innate and adaptive immune responses. Recently, it became apparent that subset of splenic B cells named marginal zone B cells (MZB cells) exhibits unique developmental and functional features that bridge these two immunity branches. Strategically positioned at the site where blood and lymph are filtered, MZB cells represent a population of sentinels that rapidly proliferate and differentiate into IgM plasmablast cells when encountered with blood-borne, thymus-independent (TI) Ags. Moreover, MZB cells have intrinsic capability to induce potent CD4⁺ helper T cell response and cytokine production upon stimulation with soluble antigens. Due to their ability to overcome a time gap prior the establishment of the full adaptive response towards pathogens, MZB cells connect and direct innate and adaptive immunity. An additional interesting characteristic of MZB cells is capacity to function as regulatory cells in autoimmune processes. MZB cells may also contribute to the control of autoimmunity via the induction of tolerance by apoptotic cells. Importantly, in the clear association with inflammation and autoimmunity, MZB cells may transform into MALT lymphoma, representing a concurrence point for the infection, immunity and malignancy. This paper presents an insight into the complex biology of marginal zone B cells and their role in intertwining and directing innate and adaptive immune processes at the physiological and pathological level.

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.

Front-line management of indolent non-Hodgkin lymphoma in Australia. Part 2: mantle cell lymphoma and marginal zone lymphoma

Mantle cell lymphoma (MCL) and the marginal zone lymphoma (MZL) subtypes (nodal MZL, extra-nodal MZL of mucosa-associated lymphoid tissue (MALT lymphoma) and splenic MZL) are uncommon lymphoma subtypes, accounting for less than 5-10% of all non-Hodgkin lymphoma. The evidence base for therapy is therefore limited and enrolment into clinical trials is preferred. Outcomes for patients with MCL have been steadily improving mainly due to the adoption of more intense strategies in younger patients, the use of rituximab maintenance and the recent introduction of bendamustine in older patients. MZL is a more heterogeneous group of cancer with both nodal, extra-nodal and splenic subtypes. Extranodal MZL may be associated with autoimmune or infectious aetiologies, and can respond to eradication of the causative pathogen. Proton pump inhibitor plus dual antibiotics in Helicobacter pylori positive gastric MALT lymphoma is curative in many patients. Watchful waiting is appropriate in most patients with asymptomatic advanced stage disease, which tends to behave in a particularly indolent manner. Other options for symptomatic disease include splenectomy, chemoimmunotherapy with rituximab and, more recently, targeted therapies.

MiR-144: A New Possible Therapeutic Target and Diagnostic/Prognostic Tool in Cancers

MicroRNAs (miRNAs) are small and non-coding RNAs that display aberrant expression in the tissue and plasma of cancer patients when tested in comparison to healthy individuals. In past decades, research data proposed that miRNAs could be diagnostic and prognostic biomarkers in cancer patients. It has been confirmed that miRNAs can act either as oncogenes by silencing tumor inhibitors or as tumor suppressors by targeting oncoproteins. MiR-144s are located in the chromosomal region 17q11.2, which is subject to significant damage in many types of cancers. In this review, we assess the involvement of miR-144s in several cancer types by illustrating the possible target genes that are related to each cancer, and we also briefly describe the clinical applications of miR-144s as a diagnostic and prognostic tool in cancers.

Cerebral HSV-1 Vasculitis as a Fatal Complication of Immunosuppression in Non-Hodgkin´s Lymphoma: A Case Report and Review of the Literature

Patients with lymphoma are predisposed to infection because of the immunocompromised state related to the disease itself and as a consequence of chemo-/radiotherapy. Here, we report a case of Herpes-simplex virus encephalitis (HSE) in an immunosuppressed patient with splenic marginal zone lymphoma (SMZL), a rare indolent variant of non-Hodgkin´s lymphoma (NHL). The course was complicated febrile neutropenia and HSV-1-related cerebral vasculitis causing progressive ischemic stroke. This case illustrates the expanding spectrum of atypical clinical and radiological manifestations of HSE in patients treated with myelotoxic drugs. Moreover, we summarize the few central nervous system manifestations of SMZL reported in the literature and discuss distinct causes of neurological deterioration in patients with NHL.

The current role of clinical flow cytometry in the evaluation of mature B-cell neoplasms

Flow cytometry (FC) has a well-established role in the diagnostic evaluation of mature B-cell neoplasms. Effective assessment for lineage associated antigens, aberrant antigen expression, and immunoglobulin light chain restriction requires a well-designed, optimized, and controlled FC assay. However, it is important for hematopathologists to know when flow cytometry has a more limited role, and other modalities, such as immunohistochemistry, cytogenetic and molecular testing, are more important. This review will discuss the features of an optimal FC assay for the evaluation of mature B-cell neoplasms, and the current role of FC in the diagnosis and sub-classification, prognostic assessment, identification of therapeutic targets, and assessment for disease response to therapy. © 2018 International Clinical Cytometry Society.

Recurrent autoimmune hemolytic anemia in splenic marginal zone lymphoma

Autoimmune hemolytic anemia (AIHA) is a condition associated with an extensive differential diagnosis that includes lymphoid malignancies. Although AIHA occurs in about 10–25% of patients with chronic lymphocytic leukemia, it is also reported to occur in all of the other lymphoid subtypes. In this article, we report a case of recurrent AIHA in a 67-year-old woman with two acute episodes of hemolysis separated by 3 years of hematologic remission. Both episodes were severe enough to require blood transfusion, oral steroids, and rituximab. Bone marrow biopsy and immunophenotyping using flow cytometry done during both admissions confirmed the presence of splenic marginal zone lymphoma.

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.