Splenic marginal zone lymphoma: from genetics to management

Integrated spatial and multimodal single-cell transcriptomics reveal patient-dependent cell heterogeneity in splenic marginal zone lymphoma

Biological hallmarks of splenic marginal zone lymphoma (SMZL) remain poorly described. Herein, we performed in-depth SMZL characterization through multimodal single-cell analyses of paired blood/spleen samples. The 3'-single-cell RNA-sequencing, Cellular Indexing of Transcriptomes and Epitopes by sequencing, and 5'-V(D)J single-cell RNA-sequencing datasets were integrated to characterize SMZL transcriptome profiles, including B-cell receptor and T-cell receptor repertoires. Hyperexpanded B-cell clones in the spleen were at a memory-like stage, whereas recirculating tumor B-cells in blood encompassed multiple differentiation stages, indicating an unexpected desynchronization of the B-cell maturation program in SMZL cells. Spatial transcriptomics showed the enrichment of T-effector and T-follicular helper (TFH) signatures in the nodular subtype of SMZL. This latter also exhibited gene-based cell-cell interactions suggestive of dynamic crosstalk between TFH and cancer cells in transcriptomics, further substantiated by using imaging mass cytometry. Our findings provide a comprehensive high-resolution description of SMZL biological hallmarks and characterize, for the first time in situ, inter- and intra-patient heterogeneity at both transcriptomic and protein levels. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

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.

Unusual Coincidence: Concurrent Cast Nephropathy and Lymphoma Infiltration in an Influenza A-Associated Acute Kidney Injury

Acute kidney injury (AKI) poses a substantial challenge in the management of lymphoma patients and is frequently associated with diverse causative factors. Herein, we report an illustrative case involving a 47-year-old male with influenza A infection who developed severe AKI, which was incongruent with his medical history. Laboratory investigations disclosed aberrant immunoglobulin levels and urinary protein excretion, prompting further evaluation. A renal biopsy revealed the presence of infiltrating lymphoid cells and cast nephropathy, raising suspicion of an underlying hematological disorder. A comprehensive diagnostic workup, including positron emission tomography imaging and bone marrow biopsy, culminated in the definitive diagnosis of splenic marginal zone lymphoma. This case highlights the crucial significance of including lymphoma-associated kidney disorders in the evaluation of unexplained AKI, particularly when encountering unconventional clinical and laboratory results. Swift and precise intervention is of utmost importance in attaining positive results in these rare and complex clinical situations. This study underscores the persistent concern of AKI in lymphoma patients, with lymphocytic infiltration and cast nephropathy as notable elements contributing to the intricate nature of this condition.

A Rare Case of Synchronous Invasive Adenocarcinoma of the Colon and Marginal Zone Lymphoma of a Splenule Associated With Hemolytic Anemia

This case report presents a rare and intriguing clinical scenario involving a 63-year-old male with recurrent left-sided hydroureteronephrosis, hypertension, and hyperlipidemia presenting with fatigue, dyspnea, and weight loss. Laboratory findings revealed anemia, basophilic stippling, spherocytosis, and nucleated red blood cells on the peripheral blood smear, raising concerns for hemolysis. Concomitant iron deficiency anemia led to further investigations, revealing gastritis and a colonic mass. A CT scan revealed splenomegaly with an accessory spleen. The histopathological evaluation identified splenic marginal zone lymphoma (MZL) - a diagnosis supported by flow cytometry. Simultaneously, the patient was found to have a moderately differentiated colorectal adenocarcinoma on colonoscopy. This unique case highlights a rare synchronous occurrence of invasive colonic adenocarcinoma with splenule MZL, an unprecedented finding in medical literature.

Splenic marginal zone lymphoma with monoclonal IgG: A case report

RATIONALE

Splenic marginal zone lymphoma (SMZL), an indolent small B-cell lymphoma, is uncommon, and part of the patients exist plasmocytic differentiation and secrete monoclonal paraproteins including IgM predominantly. SMZL with monoclonal IgG is rarer.

PATIENT CONCERNS

We report a case of SMZL (49-year-old, male) with monoclonal IgG, MYD88L265P mutation and hepatitis B virus infection.

DIAGNOSES

The patient was presented to our hospital with aggravating complaints of dizziness, fatigue, postprandial abdominal distension, and night sweats. The diagnosis was confirmed by clinical manifestations, immunophenotype, bone marrow pathology.

INTERVENTIONS

The patient received rituximab-based chemotherapy and sequential ibrutinib in combination with entecavir.

OUTCOMES

After 1 year of follow-up, his blood routine examination had returned to normal with normal level of albumin and significantly lower globulin than before, and the spleen was of normal size.

LESSONS

We conclude that rituximab-based chemotherapy is the main treatment option for the patients with SMZL, and Bruton's tyrosine kinase inhibitor has also shown beneficial efficacy.

Hypercalcaemia of malignancy: a case of vitamin-D-mediated hypercalcaemia in lymphoma

Hypercalcaemia of malignancy (HCM) is a paraneoplastic syndrome that often portends a poor prognosis. We present an extremely rare (<1%) case of HCM due to extrarenal calcitriol (1,25-(OH)2D) production in a patient with splenic marginal zone lymphoma. A man in his 80s presented with a 3-week history of fatigue, unsteadiness and abdominal pain, and new findings of anaemia, kidney injury and hypercalcaemia. Laboratory evaluation, bone marrow biopsy and positron emission tomography/computed tomography (PET/CT) confirmed the diagnosis of splenic marginal zone lymphoma which produced calcitriol (1,25-(OH)2D3), causing the patient's hypercalcaemia.

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.

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

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

Impact of early relapse within 24 months after first-line systemic therapy (POD24) on outcomes in patients with marginal zone lymphoma: A US multisite study

Progression of disease within 24 months (POD24) from diagnosis in marginal zone lymphoma (MZL) was shown to portend poor outcomes in prior studies. However, many patients with MZL do not require immediate therapy, and the time from diagnosis-to-treatment interval can be highly variable with no universal criteria to initiate systemic therapy. Hence, we sought to evaluate the prognostic relevance of early relapse or progression within 24 months from systemic therapy initiation in a large US cohort. The primary objective was to evaluate the overall survival (OS) in the two groups. The secondary objective included the evaluation of factors predictive of POD24 and the assessment of cumulative incidence of histologic transformation (HT) in POD24 versus non-POD24 groups. The study included 524 patients with 143 (27%) in POD24 and 381 (73%) in non-POD24 groups. Patients with POD24 had inferior OS compared to those without POD24, regardless of the type of systemic therapy received (rituximab monotherapy or immunochemotherapy) at diagnosis. After adjusting for factors associated with inferior OS in the univariate Cox model, POD24 remained associated with significantly inferior OS (HR = 2.50, 95% CI = 1.53-4.09, p = 0.0003) in multivariable analysis. The presence of monoclonal protein at diagnosis and those who received first-line rituximab monotherapy had higher odds of POD24 on logistic regression analysis. Patients with POD24 had a significantly higher risk for HT compared to those without POD24. POD24 in MZL might be associated with adverse biology and could be used as an additional information point in clinical trials and investigated as a marker for worse prognosis.

[Classification of indolent B-cell lymphomas : Novelties and open questions]

The 5th edition of the WHO classification (WHO-HAEM5) and the International Consensus Classification (ICC) have considerable overlap but also some distinct differences in categorizing indolent B‑cell lymphomas. Most differences with the expected impact on the daily diagnostic routine relate to follicular lymphoma (FL). Grading of FL remains mandatory only in the ICC; a diffuse growth pattern in an FL with > 15 blasts per high-power field (FL grade 3A) is not automatically classified as DLBCL according to WHO-HAEM5, and an FL subtype with unusual morphology (blastoid or large centrocyte) and biology is recognized as an entity only in the WHO-HAEM5. With the exception of B‑prolymphocytic leukemia, which is no longer acknowledged in WHO-HAEM5, there are only minor differences between both classifications and include updated names of entities, improved diagnostic criteria, and upgrades from provisional to definite entities.

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.

Management of marginal zone lymphomas

Marginal zone lymphomas (MZLs) represent about 7% of B-cell non-Hodgkin lymphomas and include 3 different subtypes-namely, extranodal (EMZL), nodal, and splenic (SMZL). The initial assessment requires specific diagnostic and staging procedures depending on organ-related peculiarities. In particular, although positron emission tomography/computed tomography was not initially recommended, recent data have reassessed its role in the routine staging of MZL, especially when only localized treatment is planned or there is a suspicion of histologic transformation. Recent findings have improved the risk stratification of MZL patients, highlighting the association of early progression after frontline therapy with worse overall survival. A significant fraction of MZL cases may be related to specific bacterial (ie, Helicobacter pylori in gastric EMZL) or viral infections (hepatis C virus), and in the earlier phases of disease, a variable percentage of patients may respond to anti-infective therapy. Involved-site radiotherapy has a central role in the management of localized EMZL not amenable to or not responding to anti-infective therapy. Although rituximab-based treatments (bendamustine- rituximab in advanced EMZL or rituximab monotherapy in SMZL) have demonstrated favorable results, the current therapeutic scenario is predicted to rapidly change as emerging novel agents, especially Bruton's tyrosine kinase inhibitors, have demonstrated promising efficacy and safety profiles, leading to their approval in the relapsed setting. Moreover, a large variety of novel agents (phosphatidylinositol 3-kinase inhibitors, chimeric antigen receptor T-cells, bispecific antibodies) are being tested in MZL patients with encouraging preliminary results.

A roadmap for clinical trial design in marginal zone lymphoma

Marginal zone lymphoma (MZL) is commonly underrepresented in clinical trials collectively studying mostly nodal indolent lymphomas.In this manuscript we propose new inclusion and response criteria defined by MZL subtype and disease location for those with extranodal MZL. Progression of disease within 24 months is associated with poor outcomes in MZL and future studies should assess the efficacy of novel agents in this population.

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.

[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.

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

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

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.

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.

How to Diagnose and Treat CD5-Positive Lymphomas Involving the Spleen

Patients with CD5-expressing lymphomas presenting with splenomegaly are frequently diagnosed with chronic lymphocytic leukemia. The most important differential diagnosis is mantle cell lymphoma, both in its classical and leukemic, non-nodal forms, given its prognostic and therapeutic implications. Other small B-cell neoplasms that frequently involve the spleen and occasionally express CD5 include the splenic marginal zone lymphoma, hairy cell leukemia and, rarely, lymphoplasmacytic lymphoma. The frequency of CD5 positivity depends in part on the sensitivity of the detection methods employed. Usually, a combination of morphological, immunophenotypic and molecular findings allows for a precise sub-classification of CD5-positive, low-grade B-cell lymphomas of the spleen. Some of these tumors may display a mixture of small and larger B cells, raising the possibility of more aggressive lymphomas, such as diffuse large B-cell lymphomas (DLBCL). Approximately 5-10% of DLBCL are CD5-positive and some may manifest as primary splenic lesions. When available, the morphology of DLBCL in the splenic tissue is distinctive and a leukemic picture is very rare. In conclusion, the appropriate morphological and clinical context assisted by flow cytometry panels and/or immunohistochemistry allows the differential diagnosis of CD5-positive, non-Hodgkin, B-cell lymphomas involving the spleen.

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.

New Insights into the Biology and Diagnosis of Splenic Marginal Zone Lymphomas

Splenic marginal zone lymphoma (SMZL) is a small B-cell lymphoma, which has been recognized as a distinct pathological entity since the WHO 2008 classification. It classically presents an indolent evolution, but a third of patients progress rapidly and require aggressive treatments, such as immuno-chemotherapy or splenectomy, with all associated side effects. In recent years, advances in the comprehension of SMZL physiopathology have multiplied, thanks to the arrival of new devices in the panel of available molecular biology techniques, allowing the discovery of new molecular findings. In the era of targeted therapies, an update of current knowledge is needed to guide future researches, such as those on epigenetic modifications or the microenvironment of these lymphomas.

CD5 expression in marginal zone lymphoma predicts differential response to rituximab or bendamustine/rituximab

We examined outcomes of 244 patients with marginal zone lymphoma (MZL) diagnosed in 2010-2020, of which 25 (10%) expressed CD5. CD5 expression was present in 22% of splenic, 8% of nodal, and 5% of extranodal MZL, and showed frequent blood/bone marrow involvement, elevated lactate dehydrogenase, and TP53 deletions. CD5 expression was not associated with progression-free or overall survival, but it conferred a significantly higher risk of histologic transformation (22% versus 4% at 5 years, p = 0.002). Among patients receiving first-line rituximab monotherapy, CD5 expression was associated with lower response rate (30% versus 77%, p = 0.006), PFS (25% versus 45% at 3 years, p = 0.003) and OS (44% versus 77%, p = 0.010), whereas CD5 status did not significantly affect outcomes of patients receiving bendamustine with rituximab (P for interaction = 0.012 for progression-free survival). CD5-positive MZL may have a propensity to leukemic dissemination, histologic transformation, and may derive benefit from first-line bendamustine/rituximab rather than rituximab alone.

Reappraisal of surgical decision-making in patients with splenic sclerosing angiomatoid nodular transformation: Case series and literature review

BACKGROUND

Many clinicians and surgeons are unfamiliar with the sclerosing angiomatoid nodular transformation (SANT), which is gaining recognition as a benign splenic tumor. We challenge that SANT is rare and whether surgical intervention could be avoided through critical imaging review.

AIM

To evaluate the incidence of SANT among splenic tumors and the decision-making process of SANT management.

METHODS

Twenty hospitalized patients who underwent splenectomy in 2018 and 2019 in a tertiary university hospital were retrospectively reviewed, and their data on imaging, diagnosis, surgical indications, and courses were recorded. All pathology results were confirmed by pathologist. Discriminative features differentiating SANT from other non-SANT splenic tumors were descriptively analyzed in this case series.

RESULTS

Fourteen out of 20 patients who underwent splenectomy had splenic tumors, including 3 SANTs (21% splenic tumors), 6 non-SANT benign lesions (43%), 2 metastatic tumors, and 3 lymphomas. Hypointensity on T2-weighted magnetic resonance imaging (MRI), spoke wheel enhancing pattern in contrasted computed tomography or MRI, and cold spot (low fluorodeoxyglucose uptake) in positron emission tomography (PET) scan helped establish the diagnosis of SANT. Lymphoma, presenting with a hot spot on the PET scan were differentiated from SANT. Surgical indications were reformatted for splenic tumors. Splenectomy need not be performed in patients with typical imaging features of SANT.

CONCLUSION

SANT is not a rare disease entity in clinical practice. Splenectomy should not be routinely indicated as the only management option for SANT with typical imaging features.

Chronic kidney disease linked to SARS-CoV-2 infection: a case report

Background

The recent COVID-19 pandemic has raised concerns about patient diagnosis and follow-up of chronically ill patients. Patients suffering from chronic illnesses, concomitantly infected by SARS-CoV-2, globally tend to have a worse prognosis and poor outcomes. Renal tropism and acute kidney injury following SARS-CoV-2 infection has recently been described in the literature, with elevated mortality rates. Furthermore, patients with pre-existing chronic kidney disease, infected by SARS-CoV-2, should be monitored carefully. Here, we report the case of a 69-year-old patient with splenic marginal zone lymphoma, suffering from longstanding chronic kidney disease following SARS-CoV-2 infection.

Case presentation

A 69-year-old male patient previously diagnosed with pulmonary embolism and splenic marginal zone lymphoma (Splenomegaly, Matutes 2/5, CD5 negative and CD23 positive), was admitted to the hospital with shortness of breath, fever and asthenia. A nasopharyngeal swab test was performed in addition to a CT-scan, which confirmed SARS-CoV-2 infection. Blood creatinine increased following SARS-CoV-2 infection at 130 μmol/l, with usual values at 95 μmol/l. The patient was discharged at home with rest and symptomatic medical treatment (paracetamol and hydration), then readmitted to the hospital in August 2020. A kidney biopsy was therefore conducted as blood creatinine levels were abnormally elevated. Immunodetection performed in a renal biopsy specimen confirmed co-localization of SARS-CoV2 nucleocapsid and protease 3C proteins with ACE2, Lewis x and sialyl-Lewis x antigens in proximal convoluted tubules and podocytes. Co-localization of structural and non-structural viral proteins clearly demonstrated viral replication in proximal convoluted tubules in this chronically ill patient. Additionally, we observed the co-localization of sialyl-Lewis x and ACE2 receptors in the same proximal convoluted tubules. Reverse Transcriptase-Polymerase Chain Reaction test performed on the kidney biopsy was negative, with very low Ct levels (above 40). The patient was finally readmitted to the haematology department for initiation of chemotherapy, including CHOP protocol and Rituximab.

Conclusions

Our case emphasizes on the importance of monitoring kidney function in immunosuppressed patients and patients suffering from cancer following SARS-CoV-2 infection, through histological screening. Further studies will be required to decipher the mechanisms underlying chronic kidney disease and the putative role of sialyl-Lewis x and HBGA during SARS-CoV-2 infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02490-z.

Undetectable minimal residual disease is an independent prognostic factor in splenic marginal zone lymphoma

The role of minimal residual disease (MRD) in splenic marginal zone lymphoma (SMZL) has not been well studied. We prospectively designed a study to evaluate undetectable MRD (uMRD) by multiparameter flow cytometry as a prognostic factor. Residual disease level of <0·01% was defined as uMRD. A total of 71 newly diagnosed patients with bone marrow involvement were enrolled and all received rituximab-based therapy. The overall response rate (ORR) was 98·5% (70/71), with a complete remission (CR) rate of 54·9% (39/71). There were a total of 295 MRD detections in bone marrow and 77·4% patients (55/71) had uMRD. The 5-year progression-free survival (PFS) [(74·8 ± 6·5)% vs. (31·4 ± 12·6)%, P < 0·001] and 5-year overall survival (OS) [(87·2 ± 5·6)% vs. (68·9 ± 13·4)%, P = 0·035] were significantly higher in uMRD patients than in MRD-positive patients. The 5-year PFS in partial remission (PR) patients with positive MRD was significantly poorer than that of PR patients with uMRD [(21·1 ± 12·9)% vs. (83·3 ± 8·8)%, P = 0·005]. Multivariate prognostic analysis revealed that uMRD was an independent good prognostic factor for PFS (hazard ratio 0·162, 95% confidence interval 0·041-0·635; P = 0·009). All these results highlight uMRD as an independent prognostic factor in patients with SMZL, especially for patients who only achieve PR.

A phase II study of the PI3K inhibitor copanlisib in combination with the anti-CD20 monoclonal antibody rituximab for patients with marginal zone lymphoma: treatment rationale and protocol design of the COUP-1 trial

Background

Advanced stage marginal zone lymphoma (MZL) is an incurable indolent B-cell lymphoma, for which a wide variety of treatments ranging from single agent rituximab to more dose intense immunochemotherapy exists. One of the major goals in this palliative setting is to develop chemotherapy-free treatments, which approach the efficacy of immunochemotherapies, but avoid chemotherapy associated toxicity in this often elderly patient population. The PI3K inhibitor copanlisib has recently shown remarkable clinical activity in refractory or relapsed indolent B–cell lymphomas, among them MZL. Based on these data, copanlisib monotherapy was granted breakthrough designation by the FDA for the treatment of adult patients with relapsed marginal zone lymphoma who have received at least two prior therapies. However, data are still limited in particular for MZL. Based on this, the COUP-1 trial aims at testing the toxicity and efficacy of copanlisib in combination with rituximab in treatment naive and relapsed MZL.

Methods

COUP-1 is a prospective, multicenter, single-arm, open-label, non-randomized phase II trial of 6 cycles (28 days cycle) of copanlisib (60 mg intravenous day 1, 8, 15) and rituximab (375 mg/m² intravenous day 1) in the induction phase followed by a maintenance phase of copanlisib (d1, d15 every 4 weeks for a maximum of 12 cycles) and rituximab (d1 every 8 weeks for a maximum of 12 cycles) in patients aged ≥18 years with previously untreated or relapsed MZL in need of treatment. A total of 56 patients are to be enrolled. Primary endpoint is the complete response (CR) rate determined 12 months after start of induction therapy. Secondary endpoints include the overall response (OR) rate, progression free survival (PFS), overall survival (OS), safety and patient related outcome with quality of life.

The study includes a translational bio-sampling program with the prospect to measure minimal residual disease. The study was initiated in November 2019.

Discussion

The COUP-1 trial evaluates the efficacy and toxicity of the treatment of copanlisib in combination with rituximab in patients with MZL and additionally offers the chance for translational research in this heterogenous type of lymphoma.

Trial registration

ClinicalTrials.gov: NCT03474744. Registration date: 03/23/2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08464-6.

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.

Evaluating ibrutinib for the treatment of relapsed/refractory marginal zone lymphoma

Introduction: Marginal zone lymphoma (MZL) is a heterogeneous disease with a wide range of possible frontline therapies depending on the subtype; there are no shared guidelines for the treatment of relapsed/refractory MZLs. The growing evidence of the importance of the BCR pathway in the pathogenesis of B lymphoproliferative forms has led researchers to consider BTK as a potential therapeutic target in MZL.Area covered: The authors provide the reader with an evaluation of ibrutinib as a treatment option for refractory marginal zone lymphoma. The review includes an overview of the drug's pharmacokinetics and pharmacodynamics, efficacy, and safety. The authors also provide the reader with their expert perspectives on the drug and its place in the treatment of MZL.Expert opinion: The availability of new non-chemotherapeutic agents represents an important opportunity to spare excessive exposure to cytotoxic compounds. Immunomodulators and targeted agents, alone or often in combination with immunotherapy, have been shown to be effective and safe therapies in patients with relapsed/refractory (R/R) MZL. In addition, numerous studies involving new generation targeted agents, alone or in combination, are currently active in both R/R and untreated patient populations, some with encouraging preliminary results.

Emergency Splenectomy in a Patient with Splenic Marginal Zone Lymphoma, Acute Portal Vein Thrombosis, and Chronic Viral Hepatitis B

Splenic marginal zone lymphoma (SMZL) is a type of non-Hodgkin’s lymphoma (NL) that occurs in 2 out of 100 cases and is more common in women aged >60 years. A sluggish, asymptomatic course of the disease does not exclude transformation into a malignant form that occurs in 25% of patients with SMZL. Another equally important sign of an NL is thrombosis that occurs in 3.6% to 17.1% of the cases. In this report, we present a case of emergency splenectomy in a patient owing to difficulties in the diagnosis of SMZL, rapid onset of acute portal vein thrombosis, and the fulminant enlargement of the spleen accompanied by an increased risk of its rupture. Chronic hepatitis B was likely the trigger for transformation of the disease to an aggressive course. Portal vein thrombosis and the aggressive course of SMZL with rapid enlargement of the spleen and threat of its rupture in the background of viral hepatitis B required emergency splenectomy followed by anticoagulant, antiviral, and antitumor therapy.

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.

Durable ibrutinib responses in relapsed/refractory marginal zone lymphoma: long-term follow-up and biomarker analysis

Advanced marginal zone lymphoma (MZL) is an incurable B-cell malignancy dependent on B-cell receptor signaling. The phase 2 PCYC-1121 study demonstrated the safety and efficacy of single-agent ibrutinib 560 mg/d in 63 patients with relapsed/refractory MZL treated with prior rituximab (RTX) or rituximab-based chemoimmunotherapy (RTX-CIT). We report the final analysis of PCYC-1121 with median follow-up of 33.1 months (range: 1.4-44.6). Overall response rate (ORR) was 58%; median duration of response (DOR) was 27.6 months (95% confidence interval [CI]: 12.1 to not estimable [NE]); median progression-free survival (PFS) was 15.7 months (95% CI: 12.2-30.4); and median overall survival (OS) was not reached (95% CI: NE to NE). Patients with prior RTX treatment had better outcomes (ORR: 81%; median DOR: not reached [95% CI: 12.2 to NE]; median PFS: 30.4 months [95% CI: 22.1 to NE]; median OS: not reached [95% CI: 30.3 to NE]) vs those with prior RTX-CIT treatment (ORR: 51%; DOR: 12.4 months [95% CI: 2.8 to NE]; PFS: 13.8 months [95% CI: 8.3-22.5]; OS: not reached [95% CI: NE to NE]). ORRs were 63%, 47%, and 62% for extranodal, nodal, and splenic subtypes, respectively. With up to 45 months of ibrutinib treatment, the safety profile remained consistent with prior reports. The most common grade ≥3 event was anemia (16%). Exploratory biomarker analysis showed NF-κB pathway gene mutations correlated with outcomes. Final analysis of PCYC-1121 demonstrated long-term safety and efficacy of ibrutinib in patients with relapsed/refractory MZL, regardless of prior treatment or MZL subtype. This trial was registered at www.clinicaltrials.gov as #NCT01980628.

Long-term follow-up after rituximab plus bendamustine in a patient with relapsed or refractory hairy cell leukemia variant: A case report

INTRODUCTION

Hairy cell leukemia variant (HCL-v) is a rare lymphoproliferative disorder regarded as a splenic B-cell lymphoma/leukemia, unclassifiable tumor in the 2017 World Health Organization classification of lymphoid tumors. The prognosis of HCL-v is much worse than that of classical hairy cell leukemia and there is no consensus regarding the optimal treatment strategy for HCL-v. For patients with indolent lymphoma, rituximab plus bendamustine (RB) has proven effective in several clinical trials. Thus, RB is expected to be a treatment option for patients with HCL-v, but there have been few reports of its use in these patients.

PATIENT CONCERNS

A 64-year-old man presented with leukocytosis and abnormal lymphocytes in peripheral blood in a medical examination. Computed tomography revealed mild splenomegaly, but no lymph node enlargement.

DIAGNOSIS

The patient was initially diagnosed with low-grade B-cell lymphoma. After he experienced a second relapse, his clinical data were reviewed again; subsequently, he was diagnosed with HCL-v on the basis of clinical presentation, flow cytometry findings, and cytogenetic abnormalities.

INTERVENTIONS

The patient was first treated with the cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) regimen. After the regimen was ineffective, he received six cycles of RB. After relapse, the patients received an additional six cycles of RB.

OUTCOMES

The patients exhibited a slight reduction of the abnormal lymphocyte level but insufficient therapeutic efficacy during CHOP therapy. After the first cycle of RB, the patient exhibited an immediate response with the absence of minimal residual disease. He remained relapse-free for approximately 67 months. After a second relapse, complete response was again achieved with the absence of minimal residual disease following RB re-administration. He remained relapse-free for approximately 29 months after the second RB.

CONCLUSION

RB could be a treatment option for patients with relapsed or refractory HCL-v. Further research is needed to establish the optimal treatment regimen for patients of HCL-v.

Role of Notch Receptors in Hematologic Malignancies

Notch receptors are single-pass transmembrane proteins that play a critical role in cell fate decisions and have been implicated in the regulation of many developmental processes. The human Notch family comprises of four receptors (Notch 1 to 4) and five ligands. Their signaling can regulate extremely basic cellular processes such as differentiation, proliferation and death. Notch is also involved in hematopoiesis and angiogenesis, and increasing evidence suggests that these genes are involved and frequently deregulated in several human malignancies, contributing to cell autonomous activities that may be either oncogenic or tumor suppressive. It was recently proposed that Notch signaling could play an active role in promoting and sustaining a broad spectrum of lymphoid malignancies as well as mutations in Notch family members that are present in several disorders of T- and B-cells, which could be responsible for altering the related signaling. Therefore, different Notch pathway molecules could be considered as potential therapeutic targets for hematological cancers. In this review, we will summarize and discuss compelling evidence pointing to Notch receptors as pleiotropic regulators of hematologic malignancies biology, first describing the physiological role of their signaling in T- and B-cell development and homeostasis, in order to fully understand the pathological alterations reported.

Challenges and Opportunities in Marginal Zone Lymphoma: Implications of Biology on Treatment

Although sharing some common features in terms of etiology and even clinical presentation, marginal zone lymphoma is a heterogeneous group of diseases, with subtypes that can present in unexpected ways, especially with regard to autoimmune disease. There’s a proven role of antimicrobial therapy for both Helicobacter pylori and hepatitis C virus, and 10-year overall survival is high. Because this disease requires continuous treatment, therapy should be properly sequenced, with consideration given to patient comorbidities and age. Finally, B-cell receptor signaling inhibitors and immunomodulatory agents can provide responses and disease control.

Clinical and biological features of B-cell neoplasms with CDK6 translocations: an association with a subgroup of splenic marginal zone lymphomas displaying frequent CD5 expression, prolymphocytic cells, and TP53 abnormalities

A translocation involving the cyclin-dependent kinase 6 (CDK6) gene [t(CDK6)] is a rare but recurrent abnormality in B-cell neoplasms. To further characterise this aberration, we studied 57 cases; the largest series reported to date. Fluorescence in situ hybridisation analysis confirmed the involvement of CDK6 in all cases, including t(2;7)(p11;q21) immunoglobulin kappa locus (IGK)/CDK6 (n = 51), t(7;14)(q21;q32) CDK6/immunoglobulin heavy locus (IGH) (n = 2) and the previously undescribed t(7;14)(q21;q11) CDK6/T-cell receptor alpha locus (TRA)/T-cell receptor delta locus (TRD) (n = 4). In total, 10 patients were diagnosed with chronic lymphocytic leukaemia, monoclonal B-cell lymphocytosis or small lymphocytic lymphoma, and 47 had small B-cell lymphoma (SmBL) including 36 cases of marginal zone lymphoma (MZL; 34 splenic MZLs, one nodal MZL and one bronchus-associated lymphoid tissue lymphoma). In all, 18 of the 26 cytologically reviewed cases of MZL (69%) had an atypical aspect with prolymphocytic cells. Among the 47 patients with MZL/SmBL, CD5 expression was found in 26 (55%) and the tumour protein p53 (TP53) deletion in 22 (47%). The TP53 gene was mutated in 10/30 (33%); the 7q deletion was detected in only one case, and no Notch receptor 2 (NOTCH2) mutations were found. Immunoglobulin heavy-chain variable-region (IGHV) locus sequencing revealed that none harboured an IGHV1-02*04 gene. Overall survival was 82% at 10 years and not influenced by TP53 aberration. Our present findings suggest that most t(CDK6)+ neoplasms correspond to a particular subgroup of indolent marginal zone B-cell lymphomas with distinctive features.

Yescarta: A New Era for Non-Hodgkin Lymphoma Patients

The use of conventional therapeutic approaches in patients with lymphoma demonstrates significant drug resistance leading to poor prognosis with reduced median survival period. T-cell immunotherapy has diverted huge attention of the researchers in recent times to engage in the stated research studies in the pool of chemotherapy-refractory lymphoma patients. B-cell antigen CD19-targeted chimeric antigen receptor (CAR) T-cell products are approved for the treatment of non-Hodgkin B-cell refracting or relapsing lymphoma. The aim of this article is to give an idea about the use of FDA-approved anti-cancer gene therapy, Axicabtagene ciloleucel, marketed under the name of Yescarta®. Axicabtagene ciloleucel is developed from the patients' mononuclear peripheral blood cells during which T cells are orchestrated to articulate a CAR that diverts them to identify CD19-expressing cells. It is used in patients with non-Hodgkin B-cell refracting or relapsing lymphoma who had no response to prior therapeutic regiment involving the use of chemotherapeutics. Here, we review the mode of action, safety, and efficacy of Yescarta.

Changes in splenic uptake pattern associated with X-ray irradiation

Purpose

To evaluate the splenic uptake function after irradiation with high-energy X-rays.

Materials and methods

Fourteen male Wistar rats were distributed into three groups. Group 1 (n = 6) – control, non-irradiated; Group 2 (n = 4) – animals that were irradiated and studied 24 h after irradiation; and Group 3 (n = 4) – animals that were irradiated and studied 48 h after irradiation. The animals were irradiated with 8 Gy X-rays in the abdominal region. According with the groups, after 24 or 48 h, 1 ml/kg of a 50% colloidal carbon solution was injected in the left internal jugular vein. After 40 min, the spleens were removed for histological studies. Macrophages containing carbon pigments in their cytoplasms were counted in 16 consecutive microscopic fields, and their means were considered as the uptake pattern of each animal.

Results

In the control groups, carbon pigments were captured by macrophages in the red and white pulps, while in the irradiated groups, the uptake in the marginal zone, around the white pulp, was enhanced. There was no disorder on the splenic parenchyma or necrosis in histological analyzes. Qualitatively rare apoptotic events were observed, with no difference between control and irradiated animals.

Conclusion

The high-energy X-ray, used in radiotherapy, modifies the splenic clearance, enhancing the amount of marginal zone macrophages containing colloid particles. This radiation was not associated with morphological changes, nor with necrosis or apoptosis of splenic tissue.

Splenic marginal zone lymphoma: a case report and literature review

BACKGROUND

Splenic marginal zone lymphoma (SMZL) is a rare non-Hodgkin lymphoma, and much little is known about its clinical characteristics and management strategies. Here we present a case of SMZL and review relevant literature to provide a better recognition of this disease entity.

CASE PRESENTATION

A 49-year-old Chinese female was admitted to our hospital with complaints of abdominal distension and acid reflux. Physical examinations and imaging investigations suggested the presence of splenomegaly. Laboratory workups revealed mildly reduced white blood cell count otherwise was not remarkable. The patient underwent splenectomy. Histological examination combined with immunohistochemical analysis of the resected spleen confirmed the diagnosis of SMZL. The patient recovered uneventfully during follow-ups.

CONCLUSIONS

Due to the rarity and unspecific clinical features, SMZL is extremely challenging to be diagnosed preoperatively. Patients with SMZL are generally associated with favorable prognosis. Combining the staging characteristics of non-Hodgkin's lymphoma and splenic primary lymphoma may assist in clinical staging management of SMZL.

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.

Rituximab Monotherapy or in Combination with Bendamustine Is Not Inferior to Rituximab-CHOP Regimen in the Treatment of Patients with Splenic Marginal Zone Lymphoma in the Real Life

Splenic marginal zone lymphoma (SMZL) is a rare lymphoma belonging to the marginal zone lymphoproliferative disorders. Usually, SMZL occurs with indolent presentation and, when required, the standard of care is represented by rituximab-based regimens. No direct comparison of different rituximab-based combinations and polychemotherapy regimens has been conducted to date. In a monocentric cohort of 68 SMLZ patients, we showed that rituximab in monotherapy or in combination with bendamustine, compared with rituximab associated with the polychemotherapy cycle cyclophosphamide, hydroxydaunorubicin, vincristine and prednisolone (CHOP), resulted in a higher 5-year progression-free survival (91.3 ± 9% and 75 ± 15.7% vs. 30.8 ± 12.1%, p < 0.001). Platelets at diagnosis <100 ×109/L (p = 0.034, HR = 4.3) and transformation into diffuse large B-cell lymphoma (p = 0.031, HR = 4.3) were associated with a lower overall survival.

Active learning effectively identifies a minimal set of maximally informative and asymptotically performant cytotoxic structure-activity patterns in NCI-60 cell lines

The NCI-60 cancer cell line screening panel has provided insights for development of subtype-specific chemical therapies and repurposing. By extracting chemical structure and cytotoxicity patterns, virtual screening potentially complements the availability of high-throughput assay platforms and improves bioactive compound discovery rates by computational prefiltering of candidate compound libraries. Many groups report high prediction performances in computational models of NCI-60 data when using cross-validation or similar techniques, yet prospective therapy development in novel cancers may have little to no such data and further may not have the resources to perform hit identification using large compound libraries. In contrast to bulk screening and analysis, the active learning methodology has demonstrated how to identify compounds for screening in small batches and update computational models iteratively, leading to predictive models with a minimum number of compounds, and importantly clarifying data volumes at which limits in predictive ability are achieved. Here, in replicate per-cell line experiments using 50% of data (∼20 000 compounds) as the external prediction target, predictive limits are reproducibly demonstrated at the stage of systematic selection of 10-30% of the incorporable half. The pattern was consistent across all 60 cell lines. Limits of predictability are found to be correlated to the doubling times of cell lines and the number of cellular response discontinuities (activity cliffs) present per cell line. Organization into chemical scaffolds delineated degrees of predictive challenge. These results provide key insights for strategies in developing new inhibitors in existing cell lines or for future automated therapy selection in personalized oncotherapy.

Targeted next-generation sequencing reveals molecular heterogeneity in non-chronic lymphocytic leukemia clonal B-cell lymphocytosis

Non-chronic lymphocytic leukemia (non-CLL) clonal B-cell lymphocytosis (CBL) encompasses a heterogeneous group of hematologic disorders that are still poorly understood. To shed light on their biological aspects, we retrospectively analyzed a highly selected series of 28 patients, who had a clonal B-cell population in the peripheral blood and in the bone marrow, without evidence of lymphoma. Extended targeted next-generation sequencing revealed wide molecular heterogeneity with MYD88 (14%), PDE4DIP (14%), BIRC3 (11%), CCND3 (11%), NOTCH1 (11%), and TNFAIP3 (11%) as the most mutated genes. Mutations of MYD88 were "nonclassic" in most cases. Although some genetic lesions were overlapping with indolent lymphomas, mainly splenic B-cell lymphomas of marginal zone origin and splenic diffuse red pulp small B-cell lymphoma, the genetic profile of our non-CLL CBL series seemed to suggest that various pathways could be involved in the pathogenesis of these disorders, not mirroring any specific lymphoma entity. These data better enlighten the molecular characteristics of non-CLL CBL; however, more efforts are needed in order to improve the diagnostic process, prognostication, and clinical management.