Splenic marginal zone lymphoma

Marginal zone lymphomas: a consensus practice statement from the Australasian Lymphoma Alliance

Marginal zone lymphomas (MZLs) are a rare, indolent group of non-Hodgkin lymphomas with different diagnostic, genetic and clinical features and therapeutic implications. The most common is extranodal MZL of mucosa-associated lymphoid tissue, followed by splenic MZL and nodal MZL. Patients with MZL generally have good outcomes with long survival rates but frequently have a relapsing/remitting course requiring several lines of therapy. The heterogeneous presentation and relapsing course present the clinician with several diagnostic and therapeutic challenges. This position statement presents evidence-based recommendations in the setting of Australia and New Zealand.

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.

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.

Marginal zone lymphomas

The three main types of marginal zone lymphoma (MZL), recognized by the current lymphoma classifications are the extranodal MZL of mucosa-associated lymphoid tissue, the splenic MZL, and the nodal MZL. They share some karyotype lesions (trisomies of chromosomes 3 and 18, deletions at 6q23), and alterations of the nuclear factor kappa B (NFkB) pathway are also common in all of them. However, they differ in the presence of recurrent translocations, mutations affecting the Notch signaling pathway (NOTCH2 and less commonly NOTCH1), the transcription factors Kruppel-like factor 2 (KLF2) or the receptor-type protein tyrosine phosphatase delta (PTPRD). This review summarizes the most recent and significant advances in our understanding of the epidemiology, genetics, and biology of MZLs and outlines the current principles of the standard management of MZL at different anatomic sites.

[Splenic lymphoma, diagnosis and treatment]

Some common clinical situations, such as splenomegaly or lymphocytosis, or less common, such as autoimmune hemolytic anemia, cold agglutinin disease, or cryoglobulinemia can lead to the diagnosis of splenic lymphoma. Splenic lymphoma is rare, mainly of non-hodgkinian origin, encompassing very different hematological entities in their clinical and biological presentation from an aggressive form such as hepato-splenic lymphoma to indolent B-cell lymphoma not requiring treatment such as marginal zone lymphoma, the most frequent form of splenic lymphoma. These entities can be challenging to diagnose and differentiate. This review presents different clinical and biological manifestations suspicious of splenic lymphoma and proposes a diagnosis work-up. We extended the strict definition of splenic lymphoma (lymphoma exclusively involving the spleen) to lymphoma thant can be revealed by a splenomegaly and we discuss the differential diagnosis of splenomegaly.

CD5-Negative, CD10-Negative Low-Grade B-Cell Lymphoproliferative Disorders of the Spleen

CD5-negative, CD10-negative low-grade B-cell lymphoproliferative disorders (CD5-CD10-LPD) of the spleen comprise a fascinating group of indolent, neoplastic, mature B-cell proliferations that are essential to accurately identify but can be difficult to diagnose. They comprise the majority of B-cell LPDs primary to the spleen, commonly presenting with splenomegaly and co-involvement of peripheral blood and bone marrow, but with little to no involvement of lymph nodes. Splenic marginal zone lymphoma is one of the prototypical, best studied, and most frequently encountered CD5-CD10-LPD of the spleen and typically involves white pulp. In contrast, hairy cell leukemia, another well-studied CD5-CD10-LPD of the spleen, involves red pulp, as do the two less common entities comprising so-called splenic B-cell lymphoma/leukemia unclassifiable: splenic diffuse red pulp small B-cell lymphoma and hairy cell leukemia variant. Although not always encountered in the spleen, lymphoplasmacytic lymphoma, a B-cell lymphoproliferative disorder consisting of a dual population of both clonal B-cells and plasma cells and the frequent presence of the MYD88 L265P mutation, is another CD5-CD10-LPD that can be seen in the spleen. Distinction of these different entities is possible through careful evaluation of morphologic, immunophenotypic, cytogenetic, and molecular features, as well as peripheral blood and bone marrow specimens. A firm understanding of this group of low-grade B-cell lymphoproliferative disorders is necessary for accurate diagnosis leading to optimal patient management.

Hepatic Infiltration by Splenic Marginal Zone Lymphoma in a Patient With Cured Hepatitis C

Splenic marginal zone lymphoma (SMZL) accounts for only 1-2.7% of all lymphomas. Almost all patients have bone marrow (BM) involvement but only one-third has liver involvement. The higher prevalence of hepatitis C virus (HCV) infection in these patients has led to the hypothesis of viral involvement in lymphomagenesis.

In this report, we present a case of a 48-year-old woman, with cured hepatitis C, presenting with fever, weight loss, nausea, abdominal pain, and jaundice. She had leucocytosis with lymphocytosis, a progressively worsening cytocholestasis, and hepatosplenomegaly. Liver biopsy, immunophenotyping, and BM biopsy were performed, resulting in the diagnosis of SMZL. The patient started chemotherapy (rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine, and prednisolone) with an initial good response, but later progression to high-grade lymphoma and was recommended to undergo salvage chemotherapy followed by auto-transplant.

Despite the unusual liver involvement, we should consider hepatic infiltration by lymphomas, such as SMZL, especially in patients with a history of HCV infection.

Distinction of lymphoid and myeloid clonal hematopoiesis

Clonal hematopoiesis (CH) results from somatic genomic alterations that drive clonal expansion of blood cells. Somatic gene mutations associated with hematologic malignancies detected in hematopoietic cells of healthy individuals, referred to as CH of indeterminate potential (CHIP), have been associated with myeloid malignancies, while mosaic chromosomal alterations (mCAs) have been associated with lymphoid malignancies. Here, we analyzed CHIP in 55,383 individuals and autosomal mCAs in 420,969 individuals with no history of hematologic malignancies in the UK Biobank and Mass General Brigham Biobank. We distinguished myeloid and lymphoid somatic gene mutations, as well as myeloid and lymphoid mCAs, and found both to be associated with risk of lineage-specific hematologic malignancies. Further, we performed an integrated analysis of somatic alterations with peripheral blood count parameters to stratify the risk of incident myeloid and lymphoid malignancies. These genetic alterations can be readily detected in clinical sequencing panels and used with blood count parameters to identify individuals at high risk of developing hematologic malignancies.

Steering Mast Cells or Their Mediators as a Prospective Novel Therapeutic Approach for the Treatment of Hematological Malignancies

Tumor cells require signaling and close interaction with their microenvironment for their survival and proliferation. In the recent years, Mast cells have earned a greater importance for their presence and role in cancers. It is known that mast cells are attracted towards tumor microenvironment by secreted soluble chemotactic factors. Mast cells seem to exert a pro-tumorigenic role in hematological malignancies with a few exceptions where they showed anti-cancerous role. This dual role of mast cells in tumor growth and survival may be dependent on the intrinsic characteristics of the particular tumor, differences in tumor microenvironment according to tumor type, and the interactions and heterogeneity of mediators released by mast cells in the tumor microenvironment. In many studies, Mast cells and their mediators have been shown to affect tumor survival and growth, prognosis, inflammation, tumor vascularization and angiogenesis. Modulating mast cell accumulation, viability, activity and mediator release patterns may thus be important in controlling these malignancies. In this review, we emphasize on the role of mast cells in lymphoid malignancies and discuss strategies for targeting and steering mast cells or their mediators as a potential therapeutic approach for the treatment of these malignancies.

The effect of surgery on primary splenic lymphoma: A study based on SEER database

BACKGROUND

Although primary splenic lymphoma (PSL) is rare, it ranks first among splenic primary malignant cancers, and the incidence of lymphoma of spleen has gradually increased in recent years. However, the efficacy of surgery for PSL has not been clinically verified by large sample data, which has affected the formulation of relevant guidelines.

AIM

To assess whether surgery can enhance the prognosis PSL patients.

METHODS

Extracted the data of patients with PSL from The Surveillance, Epidemiology, and End Results (SEER) database, and divided the patients into surgery and non-surgery group. Kaplan-Meier curves and log-rank tests were used to compare the overall survival (OS) and cancer-specific survival (CSS). The propensity score matching (PSM) was used to match the data, then compared the OS and CSS again. The COX proportional hazard regression model was used for univariate and multivariate analysis. Finally, we performed subgroup analysis in different Ahmann stages.

RESULTS

A sum of 2207 patients with PSL were enrolled, of which 1062 (48.1%) patients received surgery, and 1145 (51.9%) patients did not undergo surgery. Overall, patients in the surgery group had better OS and CSS. After the propensity scores matching, surgery was not statistically significant in OS and CSS. In the subgroup analysis, surgery was a protective factor for the OS and CSS in Ahmann I/II. However, surgery was no statistical significance in OS and CSS in Ahmann III. In patients with Ahmann Ⅰ/Ⅱ SMZL, surgery was a protective factor for OS and CSS. In patients with Ahmann Ⅲ SMZL, surgery was also statistically significant of OS and CSS.

CONCLUSIONS

Surgery can significantly improve the prognosis of patients with Ahmann Ⅰ/Ⅱ primary splenic lymphoma, but there was no survival difference in the Ahmann Ⅲ patients with or without surgery. For patients with SMZL, surgery was effective for improving OS and CSS.

Clinico-biological features and outcome of patients with splenic marginal zone lymphoma with histological transformation

We describe 36 patients with splenic marginal zone lymphoma (SMZL) with transformation (SMZL‐T), including 15 from a series of 84 patients with SMZL diagnosed at the Hospital Clinic of Barcelona (HCB) and 21 diagnosed with SMZL‐T in other centres. In the HCB cohort, the cumulative incidence of transformation at 5 years was 15%. Predictors for transformation were cytopenias, hypoalbuminaemia, complex karyotype (CK) and both the Intergruppo Italiano Linfomi (ILL) and simplified Haemoglobin, Platelet count, lactate dehydrogenase (LDH) and extrahilar Lymphadenopathy (HPLL)/ABC scores (P < 0·05). The only independent predictor for transformation in multivariate analysis was CK [hazard ratio (HR) 4·025, P = 0·05]. Patients with SMZL‐T had a significantly higher risk of death than the remainder (HR 3·89, P < 0·001). Of the 36 patients with SMZL‐T, one developed Hodgkin lymphoma and 35 a diffuse large B‐cell lymphoma, 71% with a non‐germinal centre phenotype. The main features were B symptoms, lymphadenopathy, and high serum LDH. CK was observed in 12/22 (55%) SMZL‐T and fluorescence in situ hybridisation detected abnormalities of MYC proto‐oncogene, basic helix‐loop‐helix transcription factor (MYC), B‐cell leukaemia/lymphoma 2 (BCL2) and/or BCL6 in six of 14 (43%). In all, 21 patients received immunochemotherapy, six chemotherapy, one radiotherapy and three splenectomy. The complete response (CR) rate was 61% and the median survival from transformation was 4·92 years. Predictors for a worse survival in multivariate analysis were high‐risk International Prognostic Index (HR 5·294, P = 0·016) and lack of CR (HR 2·67, P < 0·001).

A Rare Case of Factor VII Inhibitor in a Patient Presenting with Primary Splenic Marginal Zone Lymphoma

BACKGROUND Here, we report the novel presentation of a factor VII inhibitor in association with a new diagnosis of splenic marginal zone lymphoma in a previously healthy 38-year-old woman. There are only 4 reported cases of factor VII inhibitors, none of which are secondary to a splenic marginal zone lymphoma. CASE REPORT Our patient, a 38-year-old woman, presented reporting increased abdominal swelling and early satiety. She was found to have pancytopenia, an elevated international normalized ratio (INR), normal partial thromboplastin time (PTT), and massive splenomegaly. Further investigation revealed a morphology and immunophenotype most consistent with splenic marginal zone lymphoma. A mixing study was unable to bring the INR into normal range after 60 min, confirming a factor VII inhibition. Therefore, the final diagnosis was primary splenic marginal zone lymphoma and secondary factor VII inhibitors. Owing to the elevated INR, both chemotherapy and splenectomy were avoided and we began a 4-week course of weekly rituximab infusions. After a second course of 4 treatments, there was a resolution of both the coagulopathy and the splenomegaly. At this point, the splenectomy was safely performed. Maintenance rituximab continued for 2 years. Our patient has now been in remission 12 years. CONCLUSIONS We successfully treated a rare factor VII inhibitor and its underlying splenic marginal zone lymphoma with rituximab immunotherapy. A complete response was documented by splenectomy. The patient's 12-year remission of both the lymphoma and the inhibitor helps to support the causative relationship between the lymphoma and the factor VII inhibitor.

Clinical Characteristics, Treatment and Evolution of Splenic and Nodal Marginal Zone Lymphomas-Retrospective and Multicentric Analysis of Portuguese Centers

INTRODUCTION

Treatment of Splenic (SMZL) and Nodal (NMZL) Marginal Zone Lymphoma is not consensual. Histologic transformation (HT) to aggressive lymphoma is a poorly understood event, with an unfavorable outcome.

OBJECTIVES

Describe the clinical characteristics, treatment, outcomes and incidence of HT.

METHODS

Characteristics of patients with SMZL and NMZL consecutively diagnosed in 8 Portuguese centers were retrospectively reviewed. Endpoints were overall survival (OS), time to first systemic treatment (TTFST), frequency of HT and time to transformation (TTT).

RESULTS

This study included 122 SMZL and 68 NMZL, most of them received systemic treatment: 55.4% and 76.5%, respectively. Splenectomy was performed in 58.7% of patients with SMZL. Different treatment protocols were used. OS or TTFST did not differ significantly according to treatments. Given the small sample size, no conclusion can be made concerning the role of Rituximab in the treatment of NMZL and SMZL based in these results. HT was documented in 18 patients, mainly in SMZL, with a cumulative incidence at 5 years of 4.2%. We confirmed that age is a prognostic factor.

CONCLUSION

Randomized prospective trials are needed to standardize treatment in MZL. Patients with HT did appear to have shorter OS in comparison with those who did not experience HT (OS 5 years of 68.4% vs. 80.4%), but the number of HT was too small to reach statistical significance.

Rare lymphomas in routine practice - Treatment and outcome in marginal zone lymphoma in the prospective German Tumour Registry Lymphatic Neoplasms

Owing to its heterogeneity and rarity, management of disseminated marginal zone B‐cell lymphoma (MZL) remains largely understudied. We present prospective data on choice of systemic treatment and survival of patients with MZL treated in German routine practice. Of 175 patients with MZL who had been documented in the prospective clinical cohort study Tumour Registry Lymphatic Neoplasms (NCT00889798) collecting data on systemic treatment, 58 were classified as extranodal MZL of mucosa‐associated lymphoid tissue (MALT) and 117 as non‐MALT MZL. We analyzed the most commonly used first‐line and second‐line chemo(immuno)therapies between 2009 and 2016 and examined objective response rate (ORR), progression‐free survival (PFS), overall survival (OS) and prognostic factors for survival. Compared to patients with MALT MZL, those with non‐MALT MZL more often presented with bone marrow involvement (43% vs. 14%), Ann Arbor stage III/IV (72% vs. 57%) and were slightly less often in good general condition (ECOG = 0; 41% vs. 47%). In German routine practice, rituximab‐bendamustine for a median of 6 cycles was the most frequently used first‐line (76%) and second‐line treatment (36%), with no major differences between MZL subtypes. The ORR for patients encompassing any positive response was 81%. For patients with MALT and non‐MALT MZL, respectively, 5‐years PFS was 69% (95% CI 52%–81%) and 66% (95% CI 56%–75%), 5‐years OS 79% (95% CI 65%–89%) and 75% (95% CI 66%–83%). Cox proportional hazards models showed a significantly increased risk of mortality for higher age in all patient groups. Our prospective real world data give valuable insights into the management and outcome of non‐selected patients with MZL requiring systemic treatment and can help optimize therapy recommendations.

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.

[The prognostic significance of POD24 in 106 cases with splenic marginal lymphoma with bone marrow invasion]

目的

探讨24个月内疾病进展（POD24）对伴骨髓侵犯的脾边缘区淋巴瘤（SMZL）患者总生存的影响，比较POD24与非POD24患者的临床特征。

方法

回顾性分析2002年1月至2017年1月中国医学科学院血液病医院收治的有治疗指征且经过正规治疗的伴骨髓侵犯的SMZL患者，选取随访时间足以对POD24进行判断的患者（排除因非进展因素发生死亡的患者），进行预后评估及临床特征比较。

结果

共入组患者106例，中位年龄57（25～79）岁。①临床特征：全部患者均有骨髓侵犯和脾肿大，其中巨脾59.4％（63/106），肝大14.8％（15/101）；复杂核型22.7％（18/79），13q缺失5.1％（4/78），11q缺失1.3％（1/72），17p缺失2.5％（2/80），12号染色体三体（CEP12）7.5％（4/53）。②生存分析：单因素分析提示POD24、HGB<100 g/L以及CEP12为与总生存相关的不良预后因素；多因素分析提示仅POD24有独立预后意义［HR＝20.116（95％CI 2.226～181.820），P＝0.008］。③亚组分析：POD24患者较非POD24患者起病时纵隔淋巴结肿大的发生率（63.6％对18.9％，P＝0.005）及复杂核型发生率（50.0％对17.9％，P＝0.024）明显增高；腹腔淋巴结肿大、贫血、血小板减少、白蛋白下降以及乳酸脱氢酶增高的发生率在POD24患者中更高，与非POD24患者相比差异无统计学意义（P>0.05）。

结论

POD24为影响伴骨髓侵犯的SMZL患者总生存的独立预后不良因素，起病时伴纵隔淋巴结肿大及复杂核型的患者发生POD24比例更高。

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.

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.

Multiple B cell malignancies in patients with chronic lymphocytic leukemia: epidemiology, pathology, and clinical implications

Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) is associated with increased risk for certain cancers, but relatively little is known about the risk for these patients to develop additional B cell malignancies. Here, we review the available epidemiological data on multiple B cell malignancies in CLL, discuss diagnostic methods and proper pathologic evaluation to distinguish CLL from other B cell malignancies, and address clinical challenges and unmet needs in caring for CLL patients with unrelated B cell malignancies and disease transformation. Considerations include CLL patients with unrelated monoclonal B cell lymphocytosis, biclonal CLL, secondary B cell non-Hodgkin lymphomas, and Richter syndrome - both clonally related transformation and de novo large B cell lymphoma. We address the challenges that remain in order to better understand the underlying risk factors and biology that may put CLL patients at increased risk of developing multiple B cell neoplasia.

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.

A unique bone marrow lymphoma patient presenting with an isolated mass: A case report

Bone marrow lymphoma with the onset of an isolated mass in the bone marrow is extremely rare. The present case report described a unique case of B cell lymphoblastic lymphoma (LBL) presenting with an isolated mass in the bone marrow cavity, without any organopathy or lymphadenopathy. An isolated mass in bone marrow is a rare primary manifestation of LBL. The patient in the present case report presented with pain in the right elbow, a fever, pancytopenia and splenomegaly. Additionally, no abnormality was determined in the lymph nodes, the bone marrow karyotype or a computed tomography scan of the humerus. Positron emission tomography (PET) examination revealed an increased uptake of ¹⁸F-fluorodeoxyglucose in right distal humerus. An isolated mass in the bone marrow cavity was removed by surgery. Pathological findings revealed B cell LBL. The patient received an acute lymphocytic leukemia chemotherapy regimen and achieved complete remission. However, 4 months following the initial diagnosis, the patient succumbed due to a relapse. The present case highlighted the importance of PET examination and biopsy, and the requirement to identify appropriate treatments for LBL. Additionally, it is important to broaden the differential diagnosis when an isolated mass is identified in the bone marrow cavity.