Clinical and biological significance of de novo CD5+ diffuse large B-cell lymphoma in Western countries

Treatments and Outcomes of Newly Diagnosed CD5-Positive Diffuse Large B-Cell Lymphoma: A Multi-Institutional Observational Study

CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) is characterized by a poor prognosis and frequent central nervous system (CNS) relapse. Sandwich therapy comprising dose-adjusted (DA)-EPOCH-R (etoposide, prednisolone, vincristine, cyclophosphamide, doxorubicin, and rituximab) and high-dose methotrexate (HD-MTX) (DA-EPOCH-R/HD-MTX) showed excellent efficacy and manageable safety in a phase II study of patients diagnosed with stage II-IV CD5+ DLBCL. To validate the results of that study and elucidate the current state of treatment for CD5+ DLBCL, we retrospectively analyzed the outcomes of patients with CD5+ DLBCL diagnosed between 2016 and 2021 who received anthracycline-containing chemotherapy with rituximab. Among the 346 patients evaluated, 62 (18%) received DA-EPOCH-R/HD-MTX. The median follow-up time was 43 months. In 55 patients with stage II-IV disease treated with DA-EPOCH-R/HD-MTX, the 2-year overall survival (OS), progression-free survival, and cumulative incidence of CNS relapse were 87% (95% CI, 73%-94%), 76% (95% CI, 61%-86%), and 7.3% (95% CI, 2.4%-16%), respectively. There were no treatment-related deaths. Febrile neutropenia occurred in 18 (33%) patients. Multivariate analysis of the 346 patients identified elevated serum lactate dehydrogenase levels, multiple extranodal involvement, no intrathecal MTX (IT-MTX), and no DA-EPOCH-R/HD-MTX as independent risk factors for OS. Only one CNS relapse event was observed in 28 patients who received both HD-MTX and IT-MTX. Our study provides real-world data on the treatments and outcomes of a large number of patients. The favorable survival and manageable toxicity of DA-EPOCH-R/HD-MTX have been validated in clinical settings. The use of HD-MTX and IT-MTX might be effective for preventing CNS relapse in patients with CD5+ DLBCL.

Improving access to chimeric antigen receptor T-cells for refractory or relapsing diffuse large B cell lymphoma therapy in Asia

Chimeric antigen receptor T-cell (CAR-T)-mediated therapies have shown promising clinical benefit in patients with refractory or relapsing (R/R) diffuse large B-cell lymphoma (DLBCL). However, CAR-T treatment presents challenges such as lack of drug accessibility, financial barriers, variable physician preference or experience, and risk assessment based on patient-specific characteristics. This article thus aims to provide an overview of the CAR-T landscape for R/R DLBCL in Asia, with a focus on identifying barriers to access, from the perspective of Asian and international lymphoma experts. Presently, existing clinical data indicate that CAR-T therapy is a potentially curative strategy for R/R DLBCL in addition to stem cell transplantation, provided the patient's disease profile and treatment history have been thoroughly considered. However, longer-term follow-up data from large-scale studies are needed to confirm curative potential and define optimal sequencing of CAR-T in the context of novel emerging treatments, such as bi-specific antibodies, in the management of R/R DLBCL. Consequently, further research into CAR-T would benefit from collaboration between institutions. Furthermore, there is a wide disparity in CAR-T accessibility across regions due to complicated logistics and cost, which represent a significant barrier to patients in Asia. Hence, there is a need to increase representation and engagement across different stakeholders such as policymakers, payers, and the industry to arrive at a consensus on patient selection, establish clear guidelines, and develop strategies to lower CAR-T costs. Ultimately, data can support a multi-stakeholder approach when devising strategies to make CAR-T feasible and sustainable for patients.

Long-term remission after upfront autologous hematopoietic stem cell transplant for CD5+ diffuse large-B cell lymphoma

CD5+ diffuse large B-cell lymphoma (DLBCL) is a rare subtype characterized by an inferior outcome. While dose-dense therapy shows promising activity, the optimal management remains to be determined. To evaluate the benefit of consolidative autologous hematopoietic stem cell transplantation (ASCT), we retrospectively reviewed the medical records of 47 consecutive patients with newly diagnosed de novo CD5+ DLBCL. Of 19 patients ≤ 70 of age with age-adjusted International Prognostic Index 2-3, eight underwent upfront ASCT, and nine did not, despite preserved organ function and response after induction therapy. The remaining two, ineligible for ASCT due to early progression or comorbidities, had a dismal clinical course. Among younger 17 high-risk patients eligible for ASCT, ASCT was associated with better overall (p = 0.0327) and progression-free survival (p = 0.0184). Younger patients without ASCT demonstrated similar outcomes to older patients with similar risk profiles. ASCT could be considered for high-risk CD5+ DLBCL with a response after induction therapy.

Recent Advances in Understanding the Clinical Responses of Brentuximab Vedotin in Lymphoma and the Correlation with CD30 Expression

Brentuximab vedotin (BV) is an antibody-drug conjugate that combines the CD30 monoclonal antibody with the microtubule-disrupting agent, monomethyl auristatin E, which induces apoptosis in the tumor cell upon its release from the conjugate. The safety and efficacy of BV have been assessed in several studies in patients with T- and B-cell lymphomas. This article reviews the currently available data on the distribution of CD30 expression in T- and B-cell lymphomas, as well as the various levels of CD30 positivity cutoff used in the literature. It also analyzes the relationship between CD30 expression levels and the clinical response to BV in clinical trials for both T- and B-cell lymphomas and investigates BV efficacy in patients with low or undetectable levels of CD30 and examines potential mechanisms by which BV exerts its effect on these patients. This review contributes to the growing evidence suggesting that CD30 expression levels do not predict the clinical benefit of BV as the drug demonstrated substantial efficacy in patients across a wide range of CD30 expression levels while suggesting that the antitumor activity was not associated with CD30 expression levels. Furthermore, the potential of BV as a targeted approach along with its mechanism of action is also summarized to explain its key role in the future treatments of lymphomas, especially for CD30-expressing lymphomas.

The association between NADPH oxidase (NOX) polymorphisms with immunohistochemistry and survival in diffuse large B cell lymphoma patients

The purpose of this study was to comprehensively analyze the prediction role of NADPH oxidase (NOX)-related polymorphisms (NCF4: rs1883112, CYBA: rs4673, RAC2: rs13058338) and immunohistochemical indices on survival in diffuse large B-cell lymphoma (DLBCL).The impact of NOX polymorphisms were evaluated in 335 DLBCL patients treated with R (rituximab)-CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) from Harbin Medical University Cancer Hospital. We also collected information on their immunohistochemical expression and clinical outcomes.Among the patients treated with R-CHOP therapy, the patients with CyclinD1 (+) had significantly shorter progression-free survival (PFS) (p = 0.001) and event-free survival (EFS) (p < 0.001) than CyclinD1 (-) patients. Among patients received CHOP therapy, PFS was significantly longer in CD20 (+) patients (p = 0.011) than in CD20(-) patients. Among the patients treated with R-CHOP therapy, the PFS (p = 0.020) and EFS (p < 0.001) of patients with NCF4 rs1883112 AA/AG genotype were significantly longer than the patients with GG genotype. Patients treated with R-CHOP therapy and with RAC2 rs13058338 AA/AT genotype were more likely to have grade III or higher myelosuppression compared to patients with TT genotype (p = 0.027). Patients treated with CHOP therapy and with RAC2 rs13058338 AA/AT genotype were more likely to have grade III or higher systemic adverse events (p = 0.029). Cox regression analysis showed that NCF4 rs1883112 GG genotype and CyclinD1 (+) were the factors contributing to the poor outcomes in DLBCL patients treated with R-CHOP therapy.In conclusion, the results suggested that the NCF4 rs1883112 G allele may be a poor prognostic biomarker, especially for the DLBCL patients with CD3(-), CD5 (-), CD10 (-), Bcl-2 (+), Bcl-6 (+) or Ki-67(%) < 80%.

Primary large B-cell lymphoma of the central nervous system: A reappraisal of CD5-positive cases based on clinical, pathological, and molecular evaluation

CD5 expression is seen in 5%-10% of de novo diffuse large B-cell lymphomas (DLBCLs). Primary large B-cell lymphoma of the central nervous system (PCNS-LBCL) also exhibits CD5 expression in a minority of cases, however, clinicopathological and molecular features remain largely unclarified. Here we present the clinical, molecular, and pathological features of 11 CD5-positive (+) PCNS-LBCL cases, occupying 6.7% of all 165 PCNS-LBCLs diagnosed in our institutions. While CD5+ systemic DLBCL has been recognized as a distinctive subgroup showing an aggressive clinical course, no obvious differences were found between CD5+ and CD5-negative subgroups among the present CNS patients clinically. MYD88 p.L265P and CD79B p.Y196 mutations were detected in eight (73%) and seven (64%) cases, respectively, supporting previous reports. Notably, the microenvironmental immune cells were universally PD-L1/CD274-positive, and the higher levels tended to present favorable overall survival, as already evidenced in the PCNS-LBCL series. In contrast, neoplastic PD-L1/CD274 expression was undetectable in all cases. Indeed, no structural variations or copy number alterations involving PD-1 ligands were detected by targeted-capture sequencing and fluorescence in situ hybridization. While further studies are warranted, we may have confirmed similarity between PCNS-LBCLs and intravascular large B-cell lymphomas from a molecular standpoint.

Long-term remission in a patient with NK/T cell intravascular lymphoma with autologous hematopoietic cell transplantation

Intravascular lymphoma (IVL) is a rare subtype of lymphoma, mostly of B-cell origin. A few cases of IVL have been reported as having NK/T cell origins (IVNKTL). These cases are known to be fatal, especially when systemic symptoms are present. We report the case of a patient of IVNKTL who was refractory to initial treatment and received autologous hematopoietic stem cell transplantation (auto-HSCT). She has maintained complete remission (CR) for over eight years. Our case might support the evidence of auto-HSCT for the treatment of IVNKTL with chemosensitivity.

PDLIM1, a novel miR-3940-5p target, regulates the malignant progression of diffuse large B-cell lymphoma

BACKGROUND

PDZ And LIM domain protein 1 (PDLIM1), a protein-coding gene, has been widely reported to exhibit differential expression patterns across various human cancers, including hematological malignancies. This study aimed to investigate PDLIM1 expression pattern and its functional role in diffuse large B-cell lymphoma (DLBCL) both in vitro and in vivo.

METHODS

PDLIM1 expression patterns were reanalyzed using data from the Gene Expression Omnibus, and the results were subsequently validated in patient tissue samples and a panel of four DLBCL cell lines. MicroRNA-3940-5p (miR-3940-5p) was identified as an upstream regulator of PDLIM1. The interaction between PDLIM1 and miR-3940-5p and its effects on DLBCL cellular activities and cancer development were further explored using a DLBCL mouse model.

RESULTS

Elevated PDLIM1 expression was observed in DLBCL cells and tissues. Reduced cell proliferation and increased DLBCL cell apoptosis were observed following the knockdown of this gene. Furthermore, short hairpin RNA (shRNA)-mediated PDLIM1 knockdown diminished tumorigenesis of DLBCL cells in nude mice. miR-3940-5p was identified as an upstream regulator of PDLIM1. PDLIM1 expression and function were negatively modulated by the upregulation of miR-3940-5p, consequently affecting the malignant phenotype of DLBCL cells.

CONCLUSION

These findings suggest that the miR-3940-5p/PDLIM1 axis may play a crucial role in DLBCL pathogenesis and could potentially be exploited for therapeutic interventions.

Recent advances in CD5+ diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin's lymphoma (NHL), is substantially heterogeneous. Approximately 5-10% of DLBCLs express CD5, which makes CD5+ DLBCL a rare subgroup. Different studies have shown that CD5+ DLBCL patients are often older and female and have higher lactate dehydrogenase levels, an Eastern Cooperative Oncology Group (ECOG) performance status > 1, and higher International Prognostic Index (IPI) scores. Moreover, patients often have advanced stage disease with a high incidence of central nervous system (CNS) relapse and bone marrow involvement. CD5+ DLBCL cells are more likely to express MYC, BCL-2, and MUM-1, less likely to express CD10, and most belong to the activated B-cell-like (ABC) subtype. The potential mechanisms underlying the poor prognosis of CD5+ DLBCL patients may be related to CD5-mediated B-cell receptor (BCR)-dependent and -independent pathways. The efficacy of the traditional rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen is unsatisfactory in CD5+ DLBCL patients. Despite supporting evidence from retrospective studies, it is currently unclear whether dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin plus rituximab (DA-EPOCH-R) can improve outcomes in this population. Several new drugs, such as Bruton tyrosine kinase inhibitors (BTKi), BCL-2 inhibitors, and CXCR4 antagonists, as well as immunotherapy, may help to improve the prognosis of CD5+ DLBCL patients, but additional clinical explorations are needed to determine the optimal therapeutic strategy for this disease.

Plasma circulating tumour DNA is a better source for diagnosis and mutational analysis of IVLBCL than tissue DNA

Diagnosis of intravascular large B-cell lymphoma (IVLBCL) is a challenge due to its heterogeneous clinical presentation and lack of specific markers. This retrospective study investigated the utility of circulating tumour DNA (ctDNA) sequencing for diagnosing IVLBCL and analysing its mutation landscape. A cohort of 34 IVLBCL patients enrolled and underwent plasma ctDNA targeted sequencing. The median plasma ctDNA concentration was 135.0 ng/mL, significantly higher than that in diffuse large B-cell lymphoma (DLBCL) controls. Correlations were found between ctDNA concentration and disease severity indicators, LDH and SF. Mutation analysis revealed frequent mutations in B-cell receptor and NF-κB signalling pathways, including MYD88 (56%), CD79B (44%), TNFAIP3 (38%) and IRF4 (29%). CNS involvement was significantly related with BCL6 and CD58 mutation. Patients with complicated hemophagocytic lymphohistiocytosis had significantly higher mutation rates in B2M. Comparison with DLBCL subtypes showed distinctive mutation profiles in IVLBCL. Moreover, plasma ctDNA detected more mutations with higher variant allele fraction than tissue DNA, suggesting its superiority in sensitivity and accessibility. Dynamic monitoring of ctDNA during treatment correlated with therapeutic responses. This study revealed the role of ctDNA in IVLBCL diagnosis, mutation analysis, and treatment monitoring, offering a promising avenue for improving patient diagnosis in this rare lymphoma subtype.

Aligning outcomes: DLBCL prognosis at a 4th Level University Hospital in Bogotá is comparable to high-income nations, identification of additional prognostic markers for overall survival and relapse

Introduction

Diffuse large B-cell lymphoma (DLBCL), a prevalent non-Hodgkin lymphoma subtype, displays diverse clinical outcomes with persistently high mortality and relapse rates, despite treatment advancements. Notably, the Hispanic demographic lacks consideration in existing prognostic indices for DLBCL.

Methods

A retrospective cohort study encompassing 112 DLBCL patients diagnosed between 2010 and 2020 was conducted at our institution. Patient data, including overall survival (OS), treatment response, and relapse, were analysed.

Results

With a median age of 65 years and a predominant male population (60.7%), both the International Prognostic Index (IPI) and revised IPI correlated with OS. In multivariate analysis, patients with ki-67 ≥ 60% exhibited higher mortality risk (Hazard Ratio: 2.35, 95% confidence intervals (CI) 1.05-5.27, p = 0.039), even when controlled by IPI category and B2-microglobulin levels. The absence of B symptoms served as a protective factor for relapse (p < 0.01, OR: 0.147, 95% CI 0.058-0.376) when controlling for ki-67, CD5, and IPI.

Conclusion

Our cohort demonstrated a 5-year OS rate comparable to high-income countries, highlighting the need for tailored prognostic models for Hispanic DLBCL patients. This study identifies easily accessible parameters aligning with regional resource constraints, providing insights into additional prognostic factors for DLBCL in the Hispanic population.

Clinicopathological features of CD5-positive splenic marginal zone lymphoma

AIMS

To investigate the clinicopathological features, immunophenotypes and differential diagnosis of CD5-positive splenic marginal zone lymphoma (SMZL).

METHODS

We retrospectively analysed 16 CD5-positive cases of SMZL. Assess their clinicopathological features and survival outcomes to evaluate their similarities and differences with a control group of 25 CD5-negative cases of SMZL.

RESULTS

Compared with CD5-negative patients, CD5-positive SMZL tends to be more prone to B symptoms, peripheral lymphadenopathy and extranodal infiltration, high Ann Arbor stage, high International Prognostic Index scores, high serum lactic dehydrogenase and high rates of bone marrow involvement. The 5-year survival rate was significantly shorter than that of the CD5-negative group (52.1% and 81.8%, respectively).

CONCLUSIONS

There are many similarities between CD5-positive SMZL and classical CD5-negative SMZL in clinical presentations, morphology and immunohistochemistry, but the former may have a more aggressive clinical course with a poorer prognosis.

CD5 Gene Signature Identifies Diffuse Large B-Cell Lymphomas Sensitive to Bruton's Tyrosine Kinase Inhibition

PURPOSE

A genetic classifier termed LymphGen accurately identifies diffuse large B-cell lymphoma (DLBCL) subtypes vulnerable to Bruton's tyrosine kinase inhibitors (BTKis), but is challenging to implement in the clinic and fails to capture all DLBCLs that benefit from BTKi-based therapy. Here, we developed a novel CD5 gene expression signature as a biomarker of response to BTKi-based therapy in DLBCL.

METHODS

CD5 immunohistochemistry (IHC) was performed on 404 DLBCLs to identify CD5 IHC+ and CD5 IHC- cases, which were subsequently characterized at the molecular level through mutational and transcriptional analyses. A 60-gene CD5 gene expression signature (CD5sig) was constructed using genes differentially expressed between CD5 IHC+ and CD5 IHC- non-germinal center B-cell-like (non-GCB DLBCL) DLBCLs. This CD5sig was applied to external DLBCL data sets, including pretreatment biopsies from patients enrolled in the PHOENIX study (n = 584) to define the extent to which the CD5sig could identify non-GCB DLBCLs that benefited from the addition of ibrutinib to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP).

RESULTS

CD5 expression was observed in 12% of non-GCB DLBCLs. CD5+ DLBCLs displayed transcriptional features of B-cell receptor (BCR) activation and were enriched for BCR-activating mutations known to correlate with BTKi sensitivity. However, most CD5+ DLBCLs lacked canonical BCR-activating mutations or were LymphGen-unclassifiable (LymphGen-Other). The CD5sig recapitulated these findings in multiple independent data sets, indicating its utility in identifying DLBCLs with genetic and nongenetic bases for BCR dependence. Supporting this notion, CD5sig+ DLBCLs derived a selective survival advantage from the addition of ibrutinib to R-CHOP in the PHOENIX study, independent of LymphGen classification.

CONCLUSION

CD5sig is a useful biomarker to identify DLBCLs vulnerable to BTKi-based therapies and complements current biomarker approaches by identifying DLBCLs with genetic and nongenetic bases for BTKi sensitivity.

IRF4 rearrangement may predict favorable prognosis in children and young adults with primary head and neck large B-cell lymphoma

PURPOSE

Large B-cell lymphoma with IRF4 rearrangement (LBCL, IRF4+) has been recently recognized as a specific entity that is frequently associated with young age and favorable prognosis. However, whether the good outcome of the disease is due to IRF4+ or other factors remains obscure. We thus analyzed 100 young patients with primary head and neck LBCL to see the clinicopathologic correlates of IRF4+.

METHODS

The histopathology, immunophenotype, IRF4 status of the tumors, and clinical data were reviewed.

RESULTS

Twenty-one tumors were diagnosed as LBCL, IRF4+, which were more frequently associated with a follicular growth pattern, medium-sized blastoid cytology, germinal center B-cell-like, and CD5+ phenotype, compared with IRF4- ones. While most of the patients received chemotherapy with or without radiation, eight IRF4+ patients received mere surgical resection of the tumor and exhibited excellent outcome. IRF4+ cases featured a significantly higher complete remission rate, and better survivals compared with IRF4- ones. Multivariate analysis confirmed IRF4+ correlates with a better survival.

CONCLUSION

Our work confirmed the unique clinicopathologic features of LBCL, IRF4+, and disclosed for the first time the independent favorable prognostic impact of IRF4+. These findings may further unravel the heterogeneity of LBCL occurring in youth, and aid in risk stratification and tailoring the therapeutic strategy.

The International Consensus Classification of Mature Lymphoid Neoplasms: a report from the Clinical Advisory Committee

Since the publication of the Revised European-American Classification of Lymphoid Neoplasms in 1994, subsequent updates of the classification of lymphoid neoplasms have been generated through iterative international efforts to achieve broad consensus among hematopathologists, geneticists, molecular scientists, and clinicians. Significant progress has recently been made in the characterization of malignancies of the immune system, with many new insights provided by genomic studies. They have led to this proposal. We have followed the same process that was successfully used for the third and fourth editions of the World Health Organization Classification of Hematologic Neoplasms. The definition, recommended studies, and criteria for the diagnosis of many entities have been extensively refined. Some categories considered provisional have now been upgraded to definite entities. Terminology for some diseases has been revised to adapt nomenclature to the current knowledge of their biology, but these modifications have been restricted to well-justified situations. Major findings from recent genomic studies have impacted the conceptual framework and diagnostic criteria for many disease entities. These changes will have an impact on optimal clinical management. The conclusions of this work are summarized in this report as the proposed International Consensus Classification of mature lymphoid, histiocytic, and dendritic cell tumors.

CD5+ diffuse large B-cell lymphoma has heterogeneous clinical features and poor prognosis: a single-center retrospective study in China

Objective

De novo CD5-positive (CD5+) diffuse large B-cell lymphoma (DLBCL) has different clinical characteristics compared with CD5-negative (CD5−) DLBCL. However, few studies have been reported in Chinese cohorts. We investigated the clinical features and prognosis of patients with CD5+ DLBCL and summarized the related literature.

Methods

Data from 245 patients with newly diagnosed DLBCL were retrospectively assessed.

Results

Thirty-one and 214 patients were diagnosed with CD5+ DLBCL or CD5− DLBCL, respectively. In the CD5+ DLBCL group, there were significantly higher proportions of patients with older age (≥60 years), International Prognostic Index (IPI) ≥3, Eastern Cooperative Oncology Group (ECOG) scores ≥ 2, bone marrow involvement, positive B-cell lymphoma 2 expression, and positive MYC expression. Survival analysis showed that CD5+ DLBCL had a markedly poorer 2-year progression-free survival than CD5− DLBCL (18.2% vs. 56.2%). Univariate analysis indicated that age ≥60 years, ECOG score ≥ 2, IPI ≥ 3, B symptoms, and no rituximab-based treatment were poor predictive factors for overall survival (OS). Multivariate analysis revealed that B symptoms and no rituximab-based treatment, but not positive CD5 expression, were independent factors for OS.

Conclusions

Patients with CD5+ DLBCL had heterogeneous clinical characteristics and poor survival. The development of more targeted and effective therapies is needed.

Clinicopathologic Features and Genomic Signature of De Novo CD5+ Diffuse Large B-Cell Lymphoma: A Multicenter Collaborative Study

De novo CD5+ diffuse large B-cell lymphoma (DLBCL) has poor survival in the era of immunochemotherapy. Accurate gene-based typing and prognostic stratification can enhance the development of effective individualized treatments. Therefore, we conducted a multicenter retrospective study to evaluate the clinicopathologic characteristics, genomic profiles, and prognostic parameters of 61 patients with CD5+ DLBCL and 60 patients with CD5- DLBCL, with the goal of facilitating accurate prognostic stratification and potential individualized treatment strategies. Compared with patients with CD5- DLBCL, older age, advanced stage, higher incidence of central nervous system involvement, and MYC/BCL-2 and p53 overexpression were more prevalent in CD5+ DLBCL. Most patients with CD5+ DLBCL had lymph nodes with non-germinal center B-cell-like or activated B-cell-like subtype according to immunohistochemistry or Lymph2Cx assay. Next-generation sequencing showed that the proportion of MCD subtype (based on the co-occurrence of MYD88 and CD79B mutations) in the CD5+ DLBCL cohort was higher than that in the CD5- DLBCL cohort (54.2% vs. 13.0%, P=0.005). Compared with the CD5- cohort, CD5+ DLBCL patients showed poor 5-year overall survival (70.9% vs. 39.0%, P<0.001). Kaplan-Meier survival analysis indicated that cell of origin, MYC/BCL-2, p53, and BCL-6 expression did not have a prognostic impact on patients with CD5+ DLBCL. Multivariate analysis showed that age above 76 years, advanced stage, higher incidence of central nervous system involvement, and hypoalbuminemia were independent factors for poor prognosis in CD5+ DLBCL patients. In summary, CD5+ DLBCL displays poor prognosis, distinctive clinicopathologic characteristics and predominant genetic features of activated B-cell-like and MCD subtypes with worse survival outcome.

Molecular subtyping of CD5+ diffuse large B-cell lymphoma based on DNA-targeted sequencing and Lymph2Cx

Background

CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) showed poor prognosis in the rituximab era, with limited research on its genetic characteristics and cell of origin (COO). We aimed to demonstrate the molecular characteristics of CD5+ DLBCL and to discover potential prognostic factors.

Methods

We included 24 cases of CD5+ DLBCL and 23 CD5-negative (CD5-) counterparts and collected their clinicopathological features. Targeted DNA sequencing of 475 lymphoma-related genes was performed, and all cases were assigned to distinct genetic subtypes using the LymphGen tool. The COO was determined by the Lymph2Cx assay. The Kaplan–Meier method and Cox proportional hazards model were applied to identify the possible prognostic factors.

Results

Compared with their CD5- counterparts, patients with CD5+ DLBCL tended to have a worse prognosis and a higher incidence of MYD88L265P and CD79B double mutation (MCD) subtype (54.17%, P = 0.005) and activated B cell-like (ABC) subtype (62.5%, P = 00017), as determined by next-generation sequencing and Lymph2Cx, respectively. Moreover, PIM1, MYD88, and KMT2D mutations were detected more frequently in CD5+ DLBCL cases (P &lt; 0.05). According to multivariate analysis, MYC/BCL2 double expression and ABC subtype were correlated with unfavorable overall survival (OS). High mRNA expression of SERPINA9 and MME showed a significant correlation with a better OS, and high expression of MME showed a significant correlation with better progression-free survival in CD5+ DLBCL.

Conclusion

The genetic profile of CD5+ DLBCL is characterized by PIM1, MYD88, and KMT2D mutations, with a higher incidence of MCD and ABC subtypes. MYC/BCL2 double expression, ABC subtype, and mRNA expression of SERPINA9 and MME are independently predictive of the prognosis of CD5+ DLBCL.

Value of the prognostic nutritional index (PNI) in patients with newly diagnosed, CD5-positive diffuse large B-cell lymphoma: A multicenter retrospective study of the Huaihai Lymphoma Working Group

BACKGROUND

CD5-positive diffuse large B-cell lymphoma (DLBCL) is a clinically rare subtype of DLBCL with aggressive clinical manifestations and a poor prognosis. It has been demonstrated that the prognostic nutritional index (PNI), an indicator of nutritional status and systemic inflammation, is a significant prognostic factor for several types of lymphoma. The objective of this multicenter retrospective study was to explore the prognostic value of the PNI in patients with CD5-positive DLBCL.

METHODS

In total, 207 patients with CD5-positive DLBCL were recruited from 11 centers of the Huaihai Lymphoma Working Group. Maximally selected rank statistics analysis was used to identify optimal cutoff points for the PNI. A Cox proportional hazards model was used for univariable and multivariable analyses. Kaplan-Meier curves were used to calculate survival rates and draw survival curves, and the log-rank test was used to compare differences between groups.

RESULTS

The median age at diagnosis was 61 years, and the 5-year overall survival rate was 47.5%. According to the maximally selected rank statistics analysis, a score of 49.7 was the optimal cutoff point for the PNI. Subgroup analysis showed that the PNI could re-stratify patients in BCL-2-negative, MYC-negative, high-intermediate-risk and high-risk International Prognostic Index, BCL-6-positive and BCL-6-negative, high Ki-67 score (≥0.9), Ann Arbor stage III/IV, Eastern Cooperative Oncology Group performance status ≥2, and germinal center B subgroups. Multivariable analysis revealed that PNI, age, Eastern Cooperative Oncology Group performance status, albumin level, and red blood cell count were independent prognostic factors for CD5-positive DLBCL.

CONCLUSIONS

The PNI was a significant prognostic indicator for CD5-positive DLBCL and was able to re-stratify the prognosis for clinicopathologic subgroups of patients with CD5-positive DLBCL.

An integrated prognostic model for diffuse large B-cell lymphoma treated with immunochemotherapy

Diffuse large B-cell lymphoma (DLBCL), the most frequent non-Hodgkin's lymphoma subtype, is characterized by strong biological, morphological, and clinical heterogeneity, but patients are treated with immunochemotherapy in a relatively homogeneous way. Here, we have used a customized NanoString platform to analyze a series of 197 homogeneously treated DLBCL cases. The platform includes the most relevant genes or signatures known to be useful for predicting response to R-CHOP (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone) in DLBCL cases. We generated a risk score that combines the International Prognostic Index with cell of origin and double expression of MYC/BCL2, and stratified the series into three groups, yielding hazard ratios from 0.15 to 5.49 for overall survival, and from 0.17 to 5.04 for progression-free survival. Group differences were highly significant (p < 0.0001), and the scoring system was applicable to younger patients (<60 years of age) and patients with advanced or localized stages of the disease. Results were validated in an independent dataset from 166 DLBCL patients treated in two distinct clinical trials. This risk score combines clinical and biological data in a model that can be used to integrate biological variables into the prognostic models for DLBCL cases.

Surface Plasmon Resonance Immunosensor with Antibody-Functionalized Magnetoplasmonic Nanoparticles for Ultrasensitive Quantification of the CD5 Biomarker

A surface plasmon resonance (SPR) immunosensor signal amplification strategy based on antibody-functionalized gold-coated magnetic nanoparticles (mAuNPs) was developed for ultrasensitive and quantitative detection of the CD5 biomarker using an indirect sandwich immunoassay format. The gold surface of the SPR sensor disk and mAuNPs was modified with a self-assembled monolayer of 11-mercaptoundecanoic acid (11-MUA), and the coupling method using N-(3-(dimethylamino)propyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide was used to immobilize capture antibodies against human CD5 (anti-CD5_2A) and detection antibodies against human CD5 (anti-CD5_2B), respectively. The mAuNPs and anti-CD5_2B conjugates (mAuNPs-anti-CD5_2B) were separated by an external magnetic field and used to amplify the SPR signal after the formation of the anti-CD5_2A/CD5 immune complex on the SPR sensor disk. Compared to the direct CD5 detection with a limit of detection (LOD) of 1.04 nM and a limit of quantification (LOQ) of 3.47 nM, the proposed sandwich immunoassay utilizing mAuNPs-anti-CD5_2B significantly improved the LOD up to 8.31 fM and the LOQ up to 27.70 fM. In addition, it showed satisfactory performance in human blood serum (recovery of 1.04 pM CD5 was 109.62%). These results suggest that the proposed signal amplification strategy has superior properties and offers the potential to significantly increase the sensitivity of the analysis.

Identifying aggressive subsets within diffuse large B-cell lymphoma: implications for treatment approach

INTRODUCTION

While the majority of patients diagnosed with diffuse large B-cell lymphoma (DLBCL) can be cured with front-line chemoimmunotherapy, a subset of patients with high-risk disease remain challenging to treat. Identification of high-risk DLBCL is important as future therapy options are explored.

AREAS COVERED

We discuss the clinical, pathologic and molecular risk stratification in DLBCL and how these factors are incorporated into the decision making for the front-line therapy.

EXPERT OPINION

Clinical and pathological risk stratification has long been the standard for identifying likelihood of future disease progression and overall survival; however, these prediction models lack the granularity of individual patient pathology and response to therapy. Molecular subtypes defined through whole exome sequencing have independent prognostic significance. While identifying molecular drivers of aggressive disease has provided the opportunity to analyze novel therapy combinations with front-line chemoimmunotherapy, only modest benefit has been observed when targeting DLBCL subtypes. Combining clinical, pathologic, and molecular data will likely result in significant improvement in our ability to identify the most aggressive DLBCL subsets. Novel therapies and trial designs will continue to play an important role as we target these at-risk populations in the future.

Genetic subtype classification using a simplified algorithm and mutational characteristics of diffuse large B-cell lymphoma in a Japanese cohort

Recent large-scale genetic studies have proposed a new genetic classification of diffuse large B-cell lymphoma (DLBCL), which is clinically and biologically heterogeneous. However, the classification methods were complicated to be introduced into clinical practice. Here we retrospectively evaluated the mutational status and copy number changes of 144 genes in 177 Japanese patients with DLBCL, using targeted DNA sequencing. We developed a simplified algorithm for classifying four genetic subtypes-MYD88, NOTCH2, BCL2, and SGK1-by assessing alterations in 18 representative genes and BCL2 and BCL6 rearrangement status, integrating the significant genes from previous studies. In our cohort and another validation cohort from published data, the classification results in our algorithm showed close agreement with the other established algorithm. A differential prognosis among the four groups was observed. The NOTCH2 group showed a particularly poorer outcome than similar groups in previous reports. Furthermore, our study revealed unreported genetic features in the DLBCL subtypes that are mainly reported in Japanese patients, such as CD5-positive DLBCL and methotrexate-associated lymphoproliferative disorders. These results indicate the utility of our simplified method for DLBCL genetic subtype classification, which can facilitate the optimisation of treatment strategies. In addition, our study highlights the genetic features of Japanese patients with DLBCL.

c-MYC and p53 expression highlight starry-sky pattern as a favourable prognostic feature in R-CHOP-treated diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a clinically heterogeneous entity, in which the first-line treatment currently consists of an immuno-chemotherapy regimen (R-CHOP). However, around 30% of patients will not respond or will relapse. Overexpression of c-MYC or p53 is frequently found in DLBCL, but an association with prognosis remains controversial, as for other biomarkers previously linked with DLBCL aggressivity (CD5, CD23, or BCL2). The aim of this study was to explore the expression of these biomarkers and their correlation with outcome, clinical, or pathological features in a DLBCL cohort. Immunohistochemical (c-MYC, p53, BCL2, CD5, and CD23), morphological ('starry-sky' pattern [SSP]), targeted gene panel sequencing by next-generation sequencing (NGS), and fluorescence in situ hybridisation analyses were performed on tissue microarray blocks for a retrospective cohort of 94 R-CHOP-treated de novo DLBCL. In univariate analyses, p53 overexpression (p53^high ) was associated with unfavourable outcome (p = 0.04) and with c-MYC overexpression (p = 0.01), whereas c-MYC overexpression was linked with an SSP (p = 0.004), but only tended towards an inferior prognosis (p = 0.06). Presence of a starry-sky morphology was found to be correlated with better survival in p53^high DLBCL (p = 0.03) and/or c-MYC-positive DLBCL (p = 0.002). Furthermore, NGS data revealed that these three variables were associated with somatic mutations (PIM1, TNFRSF14, FOXO1, and B2M) involved in B-cell proliferation, survival, metabolism, and immune signalling. Taken together, these results show that the SSP pattern seems to be a protective factor in high-risk DLBCL subgroups and highlight cell death as a built-in failsafe mechanism to control tumour growth.

Prognostic and therapeutic value of somatic mutations in diffuse large B-cell lymphoma: A systematic review

Diffuse large B-cell lymphoma (DLBCL), the most common type of Non-Hodgkin lymphoma (NHL), is a highly heterogeneous and aggressive disease. Regardless of this heterogeneity, all patients receive the same first-line therapy, which fails in 30-40 % of patients, who are either refractory or relapse after remission. With the aim of stratifying patients to improve treatment outcome, different clinical and genetic biomarkers have been studied. The present systematic review aimed to identify somatic mutations that could serve as prognosis biomarkers or as therapeutic target mutations in DLBCL. Regarding their role as prognostic markers, mutations in CD58 and TP53 seem the most promising predictors of poor outcome although the combination of different alterations and other prognostic factors could be a more powerful strategy. On the other hand, different approaches regarding targeted therapy have been proposed. Therefore, mutational analysis could help guide treatment choice in DLBCL yet further studies and clinical trials are needed.

CD5+ diffuse large B-cell lymphoma: a narrative review

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous entity, and cell surface cluster of differentiation (CD) 5 expression may represent a distinct subset. Here, we provide a narrative review of CD5+ DLBCL to understand its clinical implications. Between 5-10% of DLBCL express CD5, making it an uncommon subset. Studies have variably shown that CD5+ DLBCL may be associated with increased age, high lactate dehydrogenase, B symptoms, extra-nodal sites, higher International Prognostic Index score, and advanced stage. CD5+ DLBCLs are more likely to express Bcl-2, MYC, and MUM1; a large proportion exhibit an activated B-cell (ABC)-like phenotype. The balance of studies generally supports an independent prognostic value of CD5 in DLBCL While more aggressive first-line regimens have been advocated for CD5+ DLBCL, including dose-adjusted R-EPOCH and autologous stem cell transplant, evidence to support these approaches is lacking; further study is warranted to identify the optimal treatment strategy for this disease entity.

Molecular Update and Evolving Classification of Large B-Cell Lymphoma

Diffuse large B-cell lymphomas (DLBCLs) are aggressive B-cell neoplasms with considerable clinical, biologic, and pathologic diversity. The application of high throughput technologies to the study of lymphomas has yielded abundant molecular data leading to the identification of distinct molecular identities and novel pathogenetic pathways. In light of this new information, newly refined diagnostic criteria have been established in the fourth edition of the World Health Organization (WHO) consensus classification of lymphomas, which was revised in 2016. This article reviews the histopathological and molecular features of the various aggressive B-cell lymphoma subtypes included in the updated classification.

Prognostic molecular biomarkers in diffuse large B-cell lymphoma in the rituximab era and their therapeutic implications

Diffuse large B-cell lymphoma (DLBCL) represents a group of tumors characterized by substantial heterogeneity in terms of their pathological and biological features, a causal factor of their varied clinical outcome. This variation has persisted despite the implementation of rituximab in treatment regimens over the last 20 years. In this context, prognostic biomarkers are of great importance in order to identify high-risk patients that might benefit from treatment intensification or the introduction of novel therapeutic agents. Herein, we review current knowledge on specific immunohistochemical or genetic biomarkers that might be useful in clinical practice. Gene-expression profiling is a tool of special consideration in this effort, as it has enriched our understanding of DLBCL biology and has allowed for the classification of DLBCL by cell-of-origin as well as by more elaborate molecular signatures based on distinct gene-expression profiles. These subgroups might outperform individual biomarkers in terms of prognostication; however, their use in clinical practice is still limited. Moreover, the underappreciated role of the tumor microenvironment in DLBCL prognosis is discussed in terms of prognostic gene-expression signatures, as well as in terms of individual biomarkers of prognostic significance. Finally, the efficacy of novel therapeutic agents for the treatment of DLBCL patients are discussed and an evidence-based therapeutic approach by specific genetic subgroup is suggested.

Diffuse Large B-Cell Lymphoma: Recognition of Markers for Targeted Therapy

Diffuse large B-cell lymphomas (DLBCL)s, the most common type of Non-Hodgkin’s Lymphoma, constitute a heterogeneous group of disorders including different disease sites, strikingly diverse molecular features and a profound variability in the clinical behavior. Molecular studies and clinical trials have partially revealed the underlying causes for this variability and have made possible the recognition of some molecular variants susceptible of specific therapeutic approaches. The main histogenetic groups include the germinal center, activated B cells, thymic B cells and terminally differentiated B cells, a basic scheme where the large majority of DLBCL cases can be ascribed. The nodal/extranodal origin, specific mutational changes and microenvironment peculiarities provide additional layers of complexity. Here, we summarize the status of the knowledge and make some specific proposals for addressing the future development of targeted therapy for DLBC cases.

DA-EPOCH-R combined with high-dose methotrexate in patients with newly diagnosed stage II-IV CD5-positive diffuse large B-cell lymphoma: a single-arm, open-label, phase II study

CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) is characterized by poor prognosis and a high frequency of central nervous system relapse after standard immunochemotherapy. We conducted a phase II study to investigate the efficacy and safety of dose-adjusted (DA)- EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab) combined with high-dose methotrexate (HD-MTX) in newly diagnosed patients with CD5+ DLBCL. Previously untreated patients with stage II to IV CD5+ DLBCL according to the 2008 World Health Organization classification were eligible. Four cycles of DA-EPOCH-R followed by two cycles of HD-MTX and four additional cycles of DAEPOCH- R (DA-EPOCH-R/HD-MTX) were planned as the protocol treatment. The primary end point was 2-year progression-free survival (PFS). Between September 25, 2012, and November 11, 2015, we enrolled 47 evaluable patients. Forty-five (96%) patients completed the protocol treatment. There were no deviations or violations in the DA-EPOCH-R dose levels. The complete response rate was 91%, and the overall response rate was 94%. At a median follow up of 3.1 years (range, 2.0-4.9 years), the 2- year PFS was 79% [95% confidence interval (CI): 64-88]. The 2-year overall survival was 89% (95%CI: 76-95). Toxicity included grade 4 neutropenia in 46 (98%) patients, grade 4 thrombocytopenia 12 (26%) patients, and febrile neutropenia in 31 (66%) patients. No treatment-related death was noted during the study. DA-EPOCH-R/HD-MTX might be a first-line therapy option for stage II-IV CD5+ DLBCL and warrants further investigation. (Trial registered at: UMIN-CTR: UMIN000008507.).

Aggressive B-cell lymphomas with a primary bone marrow presentation

Aggressive B-cell lymphomas present as a heterogeneous spectrum of disease. A primary diagnosis in the bone marrow (BM) may be challenging in terms of diagnostic classification and clinical handling, owing to limited architectural information. Aggressive B-cell lymphomas can be subdivided into entities that typically present primarily in the BM, and cases with BM involvement in which the bulk of disease is present in other organs. One main topic at the 2018 BM workshop of the European Association of Haematopathology/Society of Hematopathology was therefore aggressive B-cell lymphomas with a primary BM presentation. The spectrum of cases submitted to this topic gave a good overview of commonly encountered problems, as well as unusual manifestations, and highlighted areas of imprecise disease definitions and diagnostic grey zones. The categories submitted to the workshop included cases of Burkitt lymphoma (BL) with unusual features, high-grade B-cell lymphomas (HG-BCLs) with and without so-called double/triple-hit, and diffuse large B-cell lymphomas (DLBCLs) with a primary BM presentation. Areas of difficulties included the morphological boundaries of HG-BCL not otherwise specified, cases with MYC and bcl-2 or bcl-6 translocations and terminal deoxynucleotidyl transferase (TdT) expression, which were categorised as B-cell lymphoblastic leukaemia/lymphoma if most cells showed TdT positivity, and the clinicopathological overlap between intravascular large B-cell lymphoma, CD5-positive DLBCL, and DLBCL with primary presentations in the BM, spleen, and liver. This review summarises our understanding of the main aggressive B-cell lymphoma categories with a common primary BM presentation and potential problem areas, and makes suggestions for the immunophenotypic and genetic work-up, illustrated by the interesting and challenging cases submitted to the workshop.

Immunohistochemical analysis using cell block technique leads accurate diagnosis of ovarian malignant lymphoma: A case report

INTRODUCTION

Ovarian malignant lymphoma is a rare gynecologic disease and some patients show marked ascites, similar to that observed in advanced ovarian cancer. Although radical surgery improves prognosis of ovarian cancer, treatment of lymphoma is based on chemotherapy, therefore, differential diagnosis is crucial.

PRESENTATION OF CASE

A 65-year-old woman presented with a 1-month history of abdominal distention. Pelvic ultrasonography showed an 11-cm solid mass in the pelvis. Computed tomography and magnetic resonance imaging revealed bilateral (mainly left) ovarian masses in the pelvis and multiple metastases. Laboratory examination revealed that serum CA125 levels were elevated, suggesting the existence of advanced ovarian cancer. To confirm the diagnosis, the ascites was removed via abdominocentesis. Although no malignant epithelial cells were observed, atypical lymphoid cells dispersed in the ascites were detected in the cytological analyses. Thus, for accurate diagnosis, we performed re-abdominocentesis and immunohistochemical (IHC) analysis using cell block technique. Cell block analysis showed negative staining for CD3 and positive staining for CD20 in large atypical lymphoid cells, suggesting the existence of large B-cell lymphoma. Repeat blood examination showed that the serum sIL-2R level was elevated. We decided to perform biopsy to make the final treatment decision. Histologically, the tumor demonstrated diffuse proliferation of large atypical lymphoid cells. IHC analysis showed CD3(-), CD5(+), and CD20(+). In addition, IHC analysis also showed CD79a(+), CD10(-), bcl-2(+), and cyclin D1(-). The final diagnosis was diffuse large B-cell lymphoma.

DISCUSSION AND CONCLUSION

Here, we present the case of a patient with ovarian malignant lymphoma that was diagnosed using cell block analysis.

De Novo CD5+ Primary Gastrointestinal Diffuse Large B-Cell Lymphoma: Challenges With Treatment and Clinical Course

The gastrointestinal tract is a common extranodal site for lymphomas. However, primary gastrointestinal lymphomas are rare. Diffuse large B-cell lymphomas (DLBCL) are the most commonly encountered type in the gastrointestinal tract. Most of the DLBCL are CD5 negative. CD5+ DLBCL is very rare and a poor prognostic subtype of lymphoma. We report a rare case of primary small bowel CD5+ DLBCL that evolved from being a localized low International Prognostic Index–scored disease into an advanced and aggressive disease primarily dictated by the presence of CD5 antigen positivity.

De novo CD5+ diffuse large B-cell lymphoma, NOS: clinical characteristics and outcomes in rituximab era

CD5+ diffuse large B-cell lymphoma (DLBCL), NOS represents a distinct subset of DLBCL associated with poorer outcomes and extranodal disease. We analyzed characteristics and outcomes for 102 CD5+ DLBCL patients diagnosed between 2001-2016. The majority had poor-risk disease based on R-IPI scores; 80% had extranodal disease at diagnosis. CNS relapse occurred 23% of the time. Median PFS and OS was 18.9 months and 112 months, respectively. Four-year PFS rates were 100%, 53%, and 41% for patients with R-IPI scores of very good, good, and poor, respectively. CD5+ DLBCL represents a subset of patients with poor outcomes despite rituximab and anthracycline-based regimens. There is a need for novel therapies and clinical trials for this high-risk group of patients. Given high rates of CNS relapse, better CNS prophylaxis with frontline therapy requires more study.

CD5 expression correlates with inferior survival and enhances the negative effect of p53 overexpression in diffuse large B-cell lymphoma

De novo CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) is increasingly recognized as a distinct pathologic phenomenon with a specific clinical picture. However, CD5+ DLBCL has not been studied on a large scale in China. In this study, we show that CD5+ DLBCL occurs at a low frequency (9.2%). Comparison of clinical characteristics of CD5+ vs CD5- DLBCL showed that CD5+ DLBCL was more frequently elderly (>60 years) and had B symptoms, high-performance status, stage III-IV, an IPI score >2 and bone marrow involvement. Patients with CD5+ DLBCL had tumours with a higher prevalence of BCL-2 and p53 overexpression than CD5- DLBCL. Patients with CD5+ DLBCL had inferior progression-free survival (PFS) and overall survival (OS) than did patients with CD5- DLBCL. For CD5+ DLBCL, the patients who were treated with rituximab showed significantly better PFS and OS than those treated without rituximab. However, patients treated with RCHOP showed similar PFS and OS when compared with the group treated with intensive therapy. In addition, patients with p53 and CD5 co-expression had the worst PFS and OS. In conclusion, CD5+ DLBCL was associated with unfavorable clinicopathologic variables and with inferior survival. CD5+ DLBCL has a high frequency of p53 overexpression, and CD5 augments the negative effect of p53 overexpression in DLBCL.

A practical algorithmic approach to mature aggressive B cell lymphoma diagnosis in the double/triple hit era: selecting cases, matching clinical benefit : A position paper from the Italian Group of Haematopathology (G.I.E.)

An accurate diagnosis of clinically distinct subgroups of aggressive mature B cell lymphomas is crucial for the choice of proper treatment. Presently, precise recognition of these disorders relies on the combination of morphological, immunophenotypical, and cytogenetic/molecular features. The diagnostic workup in such situations implies the application of costly and time-consuming analyses, which are not always required, since an intensified treatment option is reasonably reserved to fit patients. The Italian Group of Haematopathology proposes herein a practical algorithm for the diagnosis of aggressive mature B cell lymphomas based on a stepwise approach, aimed to select cases deserving molecular analysis, in order to optimize time and resources still assuring the optimal management for any patient.

Prognostic significance of aberrant CD5 expression in B-cell leukemia

Aberrant expression of CD5 (as a T-cell marker) is seen in some leukemia and lymphoma of B lineage origin. Given that the signaling resulting from the expression of this marker plays an essential role in the development of leukemia and lymphoma, evaluating the expression of this marker is of paramount importance. Therefore, our goal in this study was to investigate the prognostic importance of CD5 expression in B-cell leukemia and lymphoma. We evaluate CD5 expression in normal and leukemic B-cells by identifying relevant literature through a PubMed search (1998-2018) of English language papers using the terms: ‘CD5,’ ‘B-cell,’ ‘Leukemia,’ and ‘Lymphoma.’ We are doing this thorough comparison of results from CD5 positive and negative cases to make a correct decision about prognostic importance of CD5 expression in these malignancies. In a number of B-cell malignancies, CD5 is expressed in varying degrees. Due to the different origins and characteristics of these malignancies, the results of CD5 expression evaluations are heterogeneous and impossible to generalize. However, CD5 expression is sometimes associated with clinicopathologic findings, more invasive clinical course, and even resistance to treatment (specifically in DLBCL) among CD5- positive patients, which appears to be a function of CD5 signaling and its downstream factors such as STAT3. Depending on the type of malignancy, CD5 expression is associated with good or bad prognosis, which can be used as an auxiliary prognostic factor to assess the clinical course of B-cell malignancies. Moreover, the difference in expression levels of CD5 in a variety of B-cell malignancies allows for differential diagnosis of these malignancies, which can be helpful when diagnosis is difficult.

Pure intravascular recurrence of CD5-positive diffuse large B-cell lymphoma primarily arising from the nasal cavities

Background

CD5-positive diffuse large B-cell lymphoma (DLBCL) and intravascular large B-cell lymphoma (IVL) are recognized as rare subsets of large B-cell lymphoma with poor prognosis. These two categories have similar clinicopathological features suggesting that they might overlap.

Case presentation

We present a case of a 72-year-old man with submental tumors. Positron emission tomography/computed tomography (PET/CT) showed tumors in the nasal and paranasal region and multiple submental and jugular swollen lymph nodes with abnormal uptake of ¹⁸F-fluorodeoxyglucose (FDG). Histology of biopsy from nasal tumors showed diffuse infiltration of large lymphoid cells, which showed positive expressions for CD20, CD79a, CD5 and negative for CD3 on immunohistochemistry. Thus, a CD5-positive DLBCL was diagnosed. After administration of 8 cycles of R-THPCOP (rituximab, pirarubicin, cyclophosphamide, vincristine and prednisolone), complete remission was achieved. Eight months after the first chemotherapy dose, local recurrence occurred. After salvage chemotherapy, nasal and paranasal tumors and lymph node swelling disappeared on PET/CT images, although the patient suffered from respiratory disturbance. A random skin biopsy revealed IVL, which was consistent with intravascular recurrence of CD5-positive DLBCL. Bone marrow smears showed hemophagocytosis.

Conclusion

We present a rare case of primary CD5-positive DLBCL that relapsed as pure IVL after chemotherapy. Our case suggests that CD5-positive DLBCL is closely related to IVL.

Lenalidomide combined with R-GDP in a patient with refractory CD5-positive diffuse large B-cell lymphoma: A promising response and review

CD5-positive (CD5+) diffuse large B-cell lymphoma (DLBCL) is associated with poor survival compared with CD5-negative DLBCL. The clinical characteristics of CD5+ DLBCL are different from both CD5-negative DLBCL and other CD5+ B cell lymphomas. There is currently no promising chemotherapy for CD5+ DLBCL. Herein, we report a 49-year-old Asian male with refractory CD5+ DLBCL. He complained of aggravated abdominal pain and weight loss. Computed tomography scan revealed abdominal masses, widespread lymphadenopathy, splenomegaly, and intussusception of the ileocecal junction with bowel wall thickening. Core needle aspiration biopsy of an abdominal mass was performed and immunohistochemistry revealed DLBCL of nongerminal center type. In this report, the dose-intensified R-Hyper CVAD (A) regimen as salvage therapy was introduced but failed to result in substantial improvement over the initially standard R-CHOP regimen. Next, the R-GDP regimen was administered as second-line treatment, but only resulted in a partial response. However, the addition of lenalidomide to R-GDP (R2-GDP) resulted in complete remission. The clinical features, pathogenesis, and possible mechanism of action of lenalidomide in CD5+ DLBCL have been described in the literature. The results of the present case report and literature searches indicate that CD5+ DLBCL may share a common pathway with activated B-cell like (ABC) DLBCL as determined by gene expression profiling. Lenalidomide is expected to induce favorable responses in patients with CD5+ DLBCL.

Extranodal Diffuse Large B Cell Lymphoma: Molecular Features, Prognosis, and Risk of Central Nervous System Recurrence

OPINION STATEMENT

Diffuse large B cell lymphoma (DLBCL) arises from extranodal organs in about 30% of cases. Its prognosis and risk of recurrence in the central nervous system (CNS) vary according to the primary site of origin. Recent studies begin to clarify these differences using molecular classification. Testicular, breast, and uterine DLBCL (as well as possibly primary cutaneous DLBCL, leg-type) share a high prevalence of the non-germinal center B cell (non-GCB) phenotype and the MYD88/CD79B-mutated (MCD) genotype. These biologic features, which resemble primary CNS lymphoma, may underlie their stage-independent propensity for CNS involvement. Management of these lymphomas should involve CNS prophylaxis, preferably using systemic high-dose methotrexate to prevent intraparenchymal recurrence. Involvement of the kidneys, adrenal glands, ovary, bone marrow, lung, or pleura usually indicates disseminated disease, conferring worse prognosis. Involvement of these sites is often associated with high CNS-International Prognostic Index (IPI), concurrent MYC and BCL2 or BCL6 rearrangements, or intravascular lymphoma-risk factors warranting CNS prophylaxis. In contrast, craniofacial, thyroid, localized bone, or gastric lymphomas have a variable prevalence of the non-GCB phenotype and lack MYD88 mutations. Their outcomes with standard immunochemotherapy are excellent, and the risk of CNS recurrence is low. We recommend individualized consideration of CNS prophylaxis based on the CNS-IPI score and anatomical proximity in cases of epidural, orbital, or skull involvement. Rituximab-containing immunochemotherapy is a standard approach for all extranodal DLBCLs. Surgery is no longer required for any primary site, but routine consolidative radiation therapy is recommended for testicular lymphoma. Radiation therapy also appears to be associated with better progression-free survival in primary bone DLBCL. Future studies should better distinguish primary from secondary sites of extranodal involvement, and investigate the association of newly identified genotypes with the risk of CNS or systemic recurrence.