Diffuse Large B-cell Lymphoma Research Articles

Plant Virus Intratumoral Immunotherapy with CPMV and PVX Elicits Durable Antitumor Immunity in a Mouse Model of Diffuse Large B-Cell Lymphoma.

Plant viruses are naturally occurring nanoparticles and adjuvants that interact with the mammalian immune system. This property can be harnessed in vaccines and immunotherapy. We have previously demonstrated that intratumoral immunotherapy with cowpea mosaic virus (CPMV) stimulates systemic and durable antitumor immunity in mouse tumor models and canine cancer patients. Here we compared the antitumor efficacy of CPMV with potato virus X (PVX) using a mouse model B-cell lymphoma (A20 and BALB/c mice). Despite their diverse morphologies and physiochemical properties, both plant viruses elicited systemic and long-lasting antitumor immune memory, preventing the recurrence of A20 lymphoma in rechallenge experiments. Data indicate differences in the underlying mechanism: CPMV persists longer in the tumor microenvironment (TME) compared to PVX; CPMV is a potent and multivalent toll-like receptor (TLR) agonist (activating TLRs 2, 4 and 7) while PVX may only weakly engage with TLR7. While CPMV and PVX recruit myeloid cells (neutrophils)─CPMV also recruits macrophages. Data further indicate that antiviral T cells may play a role in antitumor efficacy in the case of CPMV immunotherapy, however this may not be the case for PVX. Regardless of the mechanism of action, both CPMV and PVX elicited a durable antitumor response against a B-cell lymphoma tumor model and thus are intratumoral immunotherapy candidates for clinical development.

Bendamustine–rituximab elicits dual tumoricidal and immunomodulatory responses via cGAS–STING activation in diffuse large B-cell lymphoma

BackgroundBendamustine–rituximab (BR) therapy stands out as a promising alternative for elderly patients with diffuse large B-cell lymphoma (DLBCL), demonstrating notable efficacy when conventional regimens pose challenges. Despite its clinical success,...

International Metabolic Prognostic Index Is Superior to Other Metabolic Tumor Volume-Based Prognostication Methods in a Real-Life Cohort of Diffuse Large B-Cell Lymphoma.

Baseline metabolic tumor volume (MTV) is a promising prognostic marker in diffuse large B-cell lymphoma (DLBCL). We assessed the prognostic value of 4 novel metabolic risk scores in a real-life DLBCL cohort and compared them with the revised international prognostic index (IPI). Methods: We included a consecutive series of untreated DLBCL, not otherwise specified cases that were diagnosed in our hospital from 2008 to 2021 with available baseline [18F]FDG PET/CT. Clinical data were collected retrospectively, including the individual components of the revised IPI. MTV and other radiomic features, including lesion dissemination and tumor volume surface ratio, were calculated. Four novel metabolic risk scores including the international metabolic prognostic index (IMPI), the MTV/World Health Organization performance status, the MTV/standardized maximum distance, and clinical PET models were used to calculate the risk of progression using predefined cutoffs. Survival outcomes considered were 3-y progression free survival (PFS), 3-y time to progression (TTP), and 3-y overall survival (OS). The Harrell C-index was used to assess the discriminative performance of the risk scores. A multivariable model was built. Results: We included 355 DLBCL, not otherwise specified cases with a median MTV of 219 cm3 (range, 0-5,656 cm3). The IMPI had the highest C-index for 3-y PFS, 3-y TTP, and 3-y OS among the 4 metabolic risk scores (0.674, 0.696, and 0.677, respectively). For the 3-y TTP, the IMPI outperformed the strongest clinical risk score, the IPI, although the difference in the Harrell C-indices was small (0.696 vs. 0.693). Regarding the 3-y PFS and 3-y OS, the IPI has the highest C-index of all risk scores (0.696 and 0.693). The IMPI, the MTV/World Health Organization performance status, and the IPI score can recognize a poor risk group with a 3-y OS below 50% (43%, 32%, and 39%, respectively). In multivariable analysis, the IMPI remains an independent prognostic factor (P = 0.0089; hazard ratio, 1.207; 95% CI, 1.048-1.389). MTV and standardized maximum distance have the strongest prognostic values when used as a continuous variable. The tumor volume surface ratio has no significant prognostic value in our analysis. Conclusion: The IMPI has the strongest prognostic performance compared with the other 3 novel metabolic risk scores. However, in our real-world dataset, the IMPI could not replace the IPI, and further prospective trials are needed to compare their performance.

Understanding how CD19 expression levels impact the response to loncastuximab tesirine: a plain language summary.

In this article, we summarize results from a clinical study called LOTIS-2, in which researchers looked at patients with a type of blood cancer called diffuse large B-cell lymphoma, or DLBCL for short. Patients received the drug loncastuximab tesirine, or Lonca for short, which targets a marker on the surface of tumor cells called CD19.Patient information from the LOTIS-2 study, other studies of Lonca, and information from scientific publications was used to develop a quantitative systems pharmacology (QSP) model, which can predict how Lonca works in the body. The goal was to use the QSP model to see if CD19 levels can predict tumor size changes after Lonca treatment and if Lonca can still work to treat DLBCL when CD19 levels are very low. The prior LOTIS-1 and LOTIS-2 trials demonstrated an acceptable safety profile for Lonca, and therefore the current study did not evaluate safety data. Researchers used immunohistochemistry, a common technique to evaluate CD19 expression. They found that there was no association between patients who responded to Lonca treatment and levels of CD19 on their tumor cells. Some patients with low or even undetectable levels of CD19 on their tumor cells had observable decreases in tumor size after Lonca treatment. While Lonca uses the CD19 target to find and destroy cancer cells, Lonca does not require a large amount of CD19 to kill tumor cells. These results mean that Lonca may be an effective treatment for patients with DLBCL, even if CD19 expression in tumors is undetectable by immunohistochemistry.

The metabolic role of lactate dehydrogenase in the growth of diffuse large B cell lymphoma.

Lactate dehydrogenase (LDHA) activation induces tumorigenesis by activating tumor proliferation, growth, invasion, and metastasis. Whether LDHA mediates tumor metabolism that upon diffuse large B-cell lymphoma (DLBCL) occur remains unknown. Here, we investigated how LDHA adopt tumor metabolism after activation to regulate DLBCL-inducible. We investigated LDHA is highly expressed in peripheral blood mononuclear cells (PBMCs) of DLBCL patients. Knockdown of LDHA results in an increase in the apoptosis of cells, suppression of cell growth and migration in OCI-Ly1 and OCI-Ly10 cells. We show that LDHA gains a canonical enzyme activity to produce lactate and triggers NAD + in DLBCL cells. Furthermore, p-STAT5 was identified as a downstream target of LDHA, and the p-STAT5 protein level was significantly reduced related to decreased LDHA protein expression. Collectively, our findings identify the oncogenic role of LDHA in DLBCL and suggest that LDHA can be considered as a pivotal prognostic biomarker and a potential therapeutic target.

Identification of miR-451 target genes as prognostic markers in diffuse large B-cell lymphoma

ABSTRACT Background B-cell lymphoma, a diverse malignancy, is intricately regulated by multiple factors. MicroRNAs (miRNAs) have been demonstrated to be important regulators of the initiation and progression of human B-cell lymphoma, but their functions need to be further explored. Research design and methods Two B-cell lymphoma cell lines, Romas and HBL-1, were engineered to overexpress miR-451, with cell proliferation assessed via cell counting assays. Flow cytometry was used to study the effects of miR-451 on cell cycle and apoptosis. Bioinformatics analyses were performed using GEO datasets (GSE181063, GSE32918, GSE56315) to identify DEGs, and potential miR-451 target genes were predicted using tools like ENCORI, TargetScan, and R packages. A risk model for DLBCL prognosis was developed using Cox and LASSO regression. qRT-PCR validated the expression of these target genes. Results This study revealed that miR-451 inhibited cell proliferation, arrested the cell cycle, and induced apoptosis in human DLBCL cell lines. Bioinformatics analysis identified 9 target genes (MMP9, AQP9, RIN2, EOMES, LCP2, SELPLG, MAL, SOCS5, S1PR3) significantly associated with DLBCL prognosis, suggesting a potential mechanism by which miR-451 suppresses DLBCL development. Conclusions Our study indicates that a specific set of miR-451 target genes may significantly influence DLBCL patient outcomes.

Is histopathological analysis necessary in patients undergoing sigmoidectomy for diverticular disease? A retrospective study.

The purpose of this study was to assess the utility of routine histopathological examination in patients undergoing elective sigmoidectomy for diverticular disease after full colonoscopy 1 year prior to surgery. We retrospectively analysed medical records of all patients undergoing sigmoidectomy for diverticular disease with a documented colonoscopy within 1 year before surgery from January 2013 to December 2023. We collected preoperative, intraoperative and postoperative data of all patients. The primary endpoint was the percentage of patients with an unexpectedly abnormal histopathological report compared to colonoscopy. During the study period, 207 patients undergoing sigmoidectomy for diverticular disease were included. Mean age was 62.7 ± 13.0 years and 97 (46.9%) patients were men. In eight (3.9%) cases an unexpected finding was noted on the histopathological examination: five (2.4%) of them were hyperplastic polyps with no dysplasia and no clinical relevance, two (1.0%) were polyps with low-grade dysplasia and in one case (0.5%) a diffuse large B-cell lymphoma was present in a patient with history of lymphoma treated in the past 10 years. The Goodman and Kruskal's G index was 0.953 (95% lower limit of 0.913), which indicated high concordance between the colonoscopy and the definitive histopathological examination. In our series, the preoperative colonoscopy reliably predicted the result of the histopathological specimen findings in patients undergoing sigmoidectomy for diverticular disease. Only one (0.5%) high-risk patient had an unexpected clinically significant finding. Therefore, routine histopathological examination may not be justified for all patients.

Epidemiologic trends and survival outcomes in patients with primary digestive system lymphoma in the United States.

Primary digestive system lymphoma (PDSL) is an important entity of extranodal lymphoma, yet updated epidemiologic and survival data are lacking. Patients diagnosed with PDSL between 1975 and 2020 were identified from the Surveillance, Epidemiology, and End Results database. Kaplan-Meier analysis estimated survival outcomes. Multivariable Cox regression identified independent risk factors, and nomograms were developed to predict 1-, 3-, and 5-year overall survival (OS) and cancer-specific survival (CSS). A total of 30,568 patients with PDSL were identified, with 57.9% being male and 80.4% white. The most frequent tumor site was the stomach (48.7%) and diffuse large B-cell lymphoma (DLBCL) was the predominant histologic subtype (45.0%). The overall incidence from 2016 to 2020 was 11.11 per 1,000,000 persons, with a decrease observed in lymphoma rates for the stomach, small intestine, large intestine, and pancreas. Long-term trends showed an initial rise in PDSL incidence, followed by a decline since the 1990s. The median OS across all patients was 103months, with appendiceal lymphoma showing the highest median OS of 253months. Factors including diagnosis year, age, sex, race, primary tumor site, histologic subtype, stage, and treatment modalities were significantly associated with OS and CSS. Nomograms achieved C-indices of 0.720 for OS and 0.723 for CSS in the training cohort. The incidence of PDSL initially increased but has recently declined. Survival for all PDSL patients has improved over time. Nomograms to predict survival for patients with DLBCL exhibited good predictive and discriminating abilities.

An assessment model for the efficacy of autologous CD19 chimeric antigen receptor T-cell therapy and relapse or refractory diffuse large B-cell lymphoma risk.

An assessment model for the efficacy of autologous CD19 chimeric antigen receptor T-cell therapy and relapse or refractory diffuse large B-cell lymphoma risk.

PET/computed tomography radiomics combined with clinical features in predicting sarcopenia and prognosis of diffuse large B-cell lymphoma.

The study aimed to assess the role of 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) radiomics combined with clinical features using machine learning (ML) in predicting sarcopenia and prognosis of patients with diffuse large B-cell lymphoma (DLBCL). A total of 178 DLBCL patients (118 and 60 applied for training and test sets, respectively) who underwent pretreatment 18F-FDG PET/CT were retrospectively enrolled. Clinical characteristics and PET/CT radiomics features were analyzed, and feature selection was performed using univariate logistic regression and correlation analysis. Sarcopenia prediction models were built by ML algorithms and evaluated. Besides, prognostic models were also developed, and their associations with progression-free survival (PFS) and overall survival (OS) were identified. Fourteen features were finally selected to build sarcopenia prediction and prognosis models, including two clinical (maximum standard uptake value of muscle and BMI), nine PET (seven gray-level and two first-order), and three CT (three gray-level) radiomics features. Among sarcopenia prediction models, combined clinical-PET/CT radiomics features models outperformed other models; especially the support vector machine algorithm achieved the highest area under curve of 0.862, with the sensitivity, specificity, and accuracy of 79.2, 83.3, and 78.3% in the test set. Furthermore, the consistency index based on the prognostic models was 0.753 and 0.807 for PFS and OS, respectively. The enrolled patients were subsequently divided into high-risk and low-risk groups with significant differences, regardless of PFS or OS (P < 0.05). ML models incorporating clinical and PET/CT radiomics features could effectively predict the presence of sarcopenia and assess the prognosis in patients with DLBCL.

Localized large B-cell lymphoma with MYC and BCL6 rearrangements as an unexpected finding in an appendectomy specimen.

Large B-cell lymphomas (LBLs) comprise a genetically heterogeneous group of clinically aggressive non-Hodgkin lymphomas, frequently exhibiting overlapping features with diffuse large B-cell lymphoma and Burkitt's lymphoma. We report a case of a 24-year-old, previously healthy male with a classical clinical presentation of acute appendicitis. The pathologic examination discovered a large B-cell lymphoma with MYC and BCL6 rearrangements in the excised appendix. The patient was assigned Stage IEA, IPI = 0 and received chemotherapy. This case depicts a very uncommon occurrence of fully localized LBL in a patient of an unusually young age and clinical presentation for this type of lymphoma.

A Rare Case of Diffuse Large B-cell Lymphoma in the Breast: Diagnostic Insights and Treatment Approaches

A Rare Case of Diffuse Large B-cell Lymphoma in the Breast: Diagnostic Insights and Treatment Approaches

Human herpesvirus 6 (HHV-6) encephalitis secondary to chimeric antigen receptor (CAR)-T cell therapy.

Human herpesvirus (HHV)-6 encephalitis secondary to chimeric antigen receptor (CAR)-T cell therapyis relatively rare in clinical practice and needs to be differentiated from immune effector cell-associatedneurotoxicity syndrome (ICANS). We retrospectively reported a case of HHV-6 encephalitis secondary to CAR-T cell therapy. A male patient from China with diffuse large B-cell lymphoma underwent chimeric CAR-T cell therapy anddeveloped a generalized rash on the 8th day, followed by cognitive changes, memory loss, and disorientation onthe 14th day after CAR-T cell therapy. Initially, ICANS was suspected. A lumbar puncture was performed on the 18th day. The cerebrospinal fluid (CSF) analysis revealed slightly elevated protein levels and a high presence of HHV-6B sequences by mNGS. Brain MRI showed bilateral hippocampal abnormalities. The patient was ultimatelydiagnosed with HHV-6 encephalitis and treated with ganciclovir and dexamethasone. After one week of treatment,follow-up CSF analysis showed a reduction in HHV-6B sequences. The patient was discharged with improvedmemory and orientation. HHV-6 encephalitis secondary to CAR-T cell therapy may be easily confused with ICANS. Timely andaggressive diagnostic procedures, such as mNGS of CSF and cranial imaging, along with prompt antiviral therapy,are crucial for improving patient outcomes.

The prognostic significance of MYC/BCL2 double expression in DLBCL in the genetic classification era.

Double expression (DE) is a World Health Organization-recognized adverse prognostic factor in diffuse large B-cell lymphoma (DLBCL). However, the prognostic value of DE in the genetic subtyping era and potential mechanisms remain to be explored. We enrolled 246 DLBCL patients diagnosed between December 2021 and September 2023 in a Jiangsu Province Hospital cohort and included 930 DLBCL patients from three published studies in an external cohort. Double-expression DLBCL (DEL) in the external cohort was mainly distributed in the OTHER subtype (42.0%), EZB subtype (28.3%), and MCD subtype (15.0%), whereas the MCD subtype exhibited the highest ratio of DEL. DEL was significantly related to unfavorable overall survival (OS) and progression-free survival (PFS) in DLBCL, but only in EZB and OTHER subtypes that DEL retained remarkably adverse impacts on survivals compared to non-DEL. We explored the prognostic value of clinical and genetic parameters in DEL patients and found only ST2 showed better OS than A53 in DEL patients, whereas the other subtypes showed no significant difference. DEL showed similarities with the MCD subtype in mutation profiles. Furthermore, RNA-sequencing analyses exhibited upregulation in tumor proliferation-related pathways in DEL patients, but downregulation in extracellular matrix organization, T-cell activation and proliferation, type II interferon production, and pathways associated with cell death might contribute to the poor outcomes of DEL patients.

Racial and ethnic disparities in outcomes of diffuse large B cell lymphoma in adolescent and young adults: a SEER database analysis.

Data regarding racial disparities in the incidence, treatment, and outcomes of diffuse large B-cell lymphoma (DLBCL) is limited in the adolescent and young adult (AYA) population. We utilized the surveillance, epidemiology, and end-result (SEER) registry research plus database to evaluate racial/ethnic disparities in 8605 AYA patients with DLBCL. Race/ethnicity was categorized into three main subsets: non-Hispanic Whites (NHW), non-Hispanic Blacks (NHB), and 'other races' that included Hispanics (H), American Indian/Alaskan Native (AI/AN), Asian or Pacific Islander (A/PI). NHB were more likely to present with advanced stage disease (p < 0.001) and B symptoms (p < 0.001) and were less likely to receive chemotherapy(p < 0.001) compared to non-Hispanic white (NHW) patients and other races respectively. NHB patients had inferior 5-year disease specific survival (DSS) (70% vs 85% vs 80%, p < 0.001) and 5-year overall survival (OS) (66% vs 82% vs 77%, p < 0.001) compared to NHW and other races respectively. Black race was independently associated with both inferior DSS (HR 1.55, 95% CI 1.17-2.05, p = 0.002) and OS (HR 1.41, 95% CI 1.10-1.83, p = 0.007) after adjusting for age, gender, stage, presence of B symptoms, receipt of chemotherapy and radiation. NHB-DLBCL patients also had a lower 1-year relative survival rate (RSR) compared to NHW and other races. The low RSR in NHB patients persisted up to 5 years from diagnosis unlike NHW and other races. Our study shows that despite significant therapeutic advances in DLBCL over the last two decades, NHB AYA patients with DLBCL continue to have inferior survival outcomes compared to other ethnic and racial groups with disparities arising as early as the first year of diagnosis.

A rare case of splenic marginal zone lymphoma with MYD88 mutation transformed into diffuse large B-cell lymphoma: case report and literature review.

In indolent lymphomas, histological transformation (HT) often results in a poor prognosis and presents a significant challenge in the management of these lymphomas. Previous studies have indicated that MYD88 mutations are associated with transformation in certain haematologic malignancies. We report a rare case of splenic marginal zone lymphoma (SMZL) harbouring an MYD88 mutation, which was transformed into diffuse large B-cell lymphoma (DLBCL) and accompanied by newly emerging genetic abnormalities. The role of the MYD88 gene in SMZL is currently unclear. Through this case, we reviewed relevant studies, which indicated that MYD88 mutations, along with other genetic anomalies, may play a significant role in this process. In the future, it is essential to collect more of these rare cases for further research.

Tumour assessment of ROR1 levels in various adult leukaemia and lymphoma types.

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a tumour target currently used for the development of novel therapeutic modalities, such as antibody-drug conjugates, chimeric antigen receptor T-cell therapies, and others. Success of these new drugs depends on the selection of relevant indications based on ROR1 tumour prevalence, staining heterogeneity, and subcellular localization, among other parameters. We investigated ROR1 immunophenotype using validated antibody clones for immunohistochemistry (IHC) and flow cytometry (FC), analyzing 292 tumour specimens from 7 haematological malignancies and triple negative breast cancer (TNBC) as a reference solid tumour indication. ROR1 prevalence varied significantly across distinct tumour types, showing 100% of ROR1 positivity in all chronic lymphocytic leukaemia (n = 48) and hairy cell leukaemia (n = 14) specimens analyzed via FC with ranges between 1.1-99.8% and 0.8-62.1%, respectively. Samples analysed via IHC showed ROR1 membrane/cytoplasmic positivity in 44% of mantle cell lymphoma tumour samples (n = 27; H-score range: 10-285 in positive cases); 30% in TNBC (n = 46; H-score range: 1-200); 15% in diffuse large B-cell lymphoma (n = 45; H-score: 40-250); and 11% in follicular lymphoma (n = 34; H-score: 2-300). Finally, all acute myeloid leukaemia (n = 52) and most T-cell non-Hodgkin lymphoma (n = 31/32) tested samples were negative for ROR1 via IHC. In conclusion, ROR1 shows a heterogeneous tumour cell expression profile across multiple leukaemias and lymphomas, making it a tumour target that would require different patient selection strategies to develop novel therapeutic modalities.

Inhibition of CDGSH iron‑sulfur domain 2 exhibits tumor-suppressing effects on diffuse large B-cell lymphoma (DLBCL) by inducing ferroptosis through the regulation of the NRF2/SLC7A11/GPX4 pathway

CDGSH iron‑sulfur domain 2 (CISD2) is recognized as a ferroptosis-related gene that has potential as a target for cancer treatment. However, it is still uncertain whether targeting CISD2 can modulate ferroptosis in diffuse large B-cell lymphoma (DLBCL) cells and exhibit cancer-suppressing effects. The present study thoroughly investigated the role of CISD2 in DLBCL. CISD2 was found to be overexpressed in DLBCL, and its inhibition resulted in substantial growth inhibition in DLBCL cells. The growth inhibition effect resulting from CISD2 silencing could be reversed by a ferroptosis inhibitor, whereas inhibitors of apoptosis and necrosis did not yield the same reversal. CISD2-silenced DLBCL cells exhibited increased sensitivity to growth inhibition induced by ferroptosis suppressors. The inhibition of CISD2 induced ferroptotic cell death in DLBCL cells, which was supported by the overproduction of lipid peroxides, depletion of glutathione, accumulation of iron, and increased presence of shrunken mitochondria. Further investigation revealed reduced levels of NRF2, GPX4, and SLC7A11 in CISD2-silenced DLBCL cells. The overexpression of NRF2 significantly reduced the occurrence of ferroptotic cell death in DLBCL cells in which CISD2 was silenced. Furthermore, CISD2 inhibition exhibited tumor-suppressing effects in vivo associated with the induction of ferroptotic cell death in xenografts. These findings suggest that CISD2inhibition has tumor-suppressing effects on DLBCL by promoting ferroptotic cell death via the NRF2/SLC7A11/GPX4 pathway. Therefore, CISD2 holds promise as a viable candidate target for treating DLBCL.

BCL11A expression worsens the prognosis of DLBCL and its co-expression with C-MYC predicts poor survival

Non-Hodgkin's lymphoma (NHL) is a significant global malignancy, with diffuse large B cell lymphoma (DLBCL) being the most prevalent subtype, accounting for 25-50% of newly diagnosed cases in China. Despite a 60% survival rate achieved with R-CHOP regiment for DLBCL, approximately 40% of patients experience relapse or develop resistance to treatment. While the oncogenic transcription factor B-cell chronic lymphocytic leukaemia/lymphoma 11A (BCL11A) has been implicated in various tumors, its specific role in DLBCL remains unclear. In this study, we conducted retrospective histomorphological and immunophenotypic analyses on paraffin sample tissues and collected fresh tissue samples for protein and mRNA analyses to investigate the relationship between BCL11A and DLBCL. Additionally, we classified DLBCL into subtypes based on cells of origin (COO) and examined the expressions of BCL11A, C-MYC, P53 and other protein expressions to better understand the factors contributing to poor clinical outcomes in DLBCL. Our findings revealed elevated BCL11A expression in DLBCL, with increased expression associated with worse prognosis and higher C-MYC expression. Patients exhibiting co-expression of C-MYC and BCL11A had significantly lower survival rates compared to those with singular expression. Furthermore, BCL11A protein expression levels demonstrated significant associations with P53 and C-MYC protein expression levels in the Germinal Center B-cell-like (GCB) subtype. These findings suggest that BCL11A may serve as a potential prognostic marker and therapeutic target for DLBCL.

Clinical and cytological characteristics of serous effusions in 69 cases of lymphoma patients.

To explore the value of cell morphology, immunophenotype, and gene alterations of serosal effusion in the diagnosis of lymphoma. Serosal effusion of 69 cases of lymphoma patients were collected, including 36 cases with malignant effusion and 33 cases with nonmalignant effusion. Ordinary cytology, liquid-based cytology, cellblock, and immunocytochemical staining were performed in each case, some cases were detected by fluorescence in situ hybridization for C-MYC, BCL2, and BCL6 gene translocations. T/B cell ratio in malignant and nonmalignant serosal effusions was analyzed and compared by flow cytometry (FCM)and immunohistochemical (IHC), respectively. The prognostic value of serous effusion in diffuse large B-cell lymphoma (DLBCL) was investigated and another 20 DLBCL cases without effusion were successively selected as control. The number of naive lymphocytes, apoptotic bodies, and mitotic figures were more common in malignant effusions compared with nonmalignant effusions (p < .01). The top three lymphomas in malignant effusion were DLBCL (19/36, 52.8%), mantle cell lymphoma (MCL) (4/36, 11.1%, 3 blastoid variant) and high-grade B-cell lymphoma (HGBL) (4/36, 11.1%). T/B cell ratio by FCM analysis ranged from 0.00 to 0.55 (mean 0.084) in malignant effusion, and 2.58 to 984.00 (mean 249.9) in nonmalignant effusion. The difference was significant (p = .017). The T/B cell ratio by IHC analysis ranged from 0.02 to 3.00 (mean 0.200) in malignant effusion, and 2.00-100.00 (mean 34.10) in nonmalignant effusion. The difference was significant (p = .017). In the effusions involving DLBCL, most effusions were present at the time of diagnosis (57.9%); single pleural effusions were more common (36.8%). The median overall survival times of patients with malignant effusion, nonmalignant effusion and DLBCL without serous effusion were 11, 17, and 23 months respectively (p = .04). Three patients of HGBL died, and the overall survival times were 5, 8, and 9 months, respectively. The cytomorphological characteristics combined with immunophenotype, FCM, gene rearrangement, and other tests can diagnose and classify patients with effusion as the first symptom. The T/B cell ratio is less than 1 by FCM or IHC suggesting a malignant serosal effusion. The presence of malignant effusion in DLBCL patients is an important clue for poor prognosis.