Fluid Overload-Associated Large B-Cell Lymphoma with Light Chain Restriction Type Plasma Cell Infiltration: A Case Report.

BACKGROUND Fluid overload-associated large B-cell lymphoma (FO-LBCL) is a recently described malignant lymphoma that presents with serous effusions in the pleura, peritoneum, and/or pericardium but without an identifiable lymphoma mass. This report describes the case of an 80-year-old man who presented with a pleural effusion and describes the approach to diagnosis and management of FO-LBCL. CASE REPORT We present a case of an 80-year-old man who presented with right pleural effusion and shortness of breath at work. Initial radiological assessment suggested a pleural effusion on the right side, without an identifiable mass, given the patient's symptoms and imaging characteristics. Subsequently, he underwent a pleural fluid puncture and biopsy. Based on the initial pathological assessment, malignant lymphoma, a non-epithelial tumor, was considered likely, but differentiation from reactive proliferative cells was difficult, given the patient's symptoms and cytologic characteristics. Postoperatively, histopathological examination and immunohistochemistry confirmed a diagnosis of FO-LBCL. After 1 year of follow-up, the condition had progressed and the patient died due to recurrence. CONCLUSIONS This report has presented a case of FO-LBCL in an elderly man with pleural effusion and described how this rare and recently described lymphoma was diagnosed and managed.

Vitreoretinal large B- cell lymphoma (VR- LBCL): Clinical and pathological features and treatment outcomes.

CONTEXT: Vitreoretinal large B- cell lymphoma (VR- LBCL) is a type of non- Hodgkin lymphoma confined to the eye and central nervous system (CNS). The clinical manifestations of intraocular lymphoma can precede, occur simultaneously with, or follow disease at CNS sites. It differs from other forms of extra-nodal lymphoma; in that it does not involve systemic sites other than CNS. OBJECTIVES: To analyse the clinical and pathological features, and treatment outcomes of a cohort of patients diagnosed with vitreoretinal lymphoma (VRL) in Royal Victoria Eye and Ear Hospital, Ireland between 2010 and 2024. METHOD: Retrospective review of medical records and pathology specimens of patients with ocular involvement in VR- LBCL over 14-year period and a review of the literature. RESULTS: Eight patients were included. All of them underwent pars plana vitrectomy and were confirmed to have VR- LBCL. The median age at diagnosis was 71 years. Three were men and five were women. Six had bilateral disease and two unilateral. Four of four patients had MYD88 L265P mutation present. Four patients showed a high interleukin-10 (IL-10) to interleukins-6 (IL-6) ratio in keeping with the diagnosis of VRL. Three patients had primary CNS lymphoma with subsequent eye involvement, despite systemic chemotherapy treatment. Of the five patients who presented with ocular lymphoma, two patients had CNS involvement after primary vitreoretinal lymphoma was diagnosed. Of those, one was initially treated with local intravitreal chemotherapy. Three patients had no CNS recurrence. At the time of this study, seven patients of eight are alive, four are disease free and two are on a first- line local chemotherapy treatment. One underwent treatment for CNS relapse. One patient died of the disease before commencing targeted therapy. CONCLUSION: This case series demonstrated excellent treatment outcomes for seven patients, alive at the time of the study. Both local radiotherapy and intravitreal chemotherapy achieved good ocular control with acceptable side effects and no significant difference in visual outcome. VRL is a difficult diagnosis and vitreous cytology should be prioritised in cases of vitritis unresponsive to treatment. Analysis of MYD88 L265P mutation and IL- 10: IL- 6 ratio >1 are useful adjuncts in the diagnosis of VR- LBCL, particularly in cases where limited vitreous material makes cytological evaluation challenging.

Identify truly high-risk TP53-mutated diffuse large B cell lymphoma patients and explore the underlying biological mechanisms.

TP53 mutation (TP53-mut) correlates with inferior survival in many cancers, whereas its prognostic role in diffuse large B-cell lymphoma (DLBCL) is still in controversy. Therefore, more precise risk stratification needs to be further explored for TP53-mut DLBCL patients. A set of 2637 DLBCL cases from multiple cohorts, was enrolled in our analysis. Among the 2637 DLBCL patients, 14.0% patients (370/2637) had TP53-mut. Since missense mutations account for the vast majority of TP53-mut DLBCL patients, and most non-missense mutations affect the function of the P53 protein, leading to worse survival rates, we distinguished patients with missense mutations. A TP53 missense mutation risk model was constructed based on a 150-combination machine learning computational framework, demonstrating excellent performance in predicting prognosis. Further analysis revealed that patients with high-risk missense mutations are significantly associated with early progression and exhibit dysregulation of multiple immune and metabolic pathways at the transcriptional level. Additionally, the high-risk group showed an absolutely suppressed immune microenvironment. To stratify the entire cohort of TP53-mut DLBCL, we combined clinical characteristics and ultimately constructed the TP53 Prognostic Index (TP53PI) model. In summary, we identified the truly high-risk TP53-mut DLBCL patients and explained this difference at the mutation and transcriptional levels.

Clinical characteristics and outcome of early-stage diffuse large B cell lymphoma of female genital track: A retrospective study of the Hellenic cooperative lymphoma group.

Involvement of female genital track (FGT) by diffuse large B cell lymphoma (DLBCL) represents an extremely rare diagnosis. Especially data regarding early-stage disease (i.e., IE, IIE) is very limited. Importantly, previous studies showed controversial results about the risk of central nervous system (CNS) relapse in this entity. Herein, we describe one of the largest reported real-world series of patients with early-stage FGT DLBCL aiming to investigate the clinicopathological characteristics, response to therapy and survival outcomes in the era of immunochemotherapy. We analyzed 21 consecutive patients with biopsy proven DLBCL from uterus or ovary classified as stage IE or IIE out of 1905 newly diagnosed DLBCL patients (1.1%). Uterine and ovarian localization was observed in 14 and seven patients, respectively. Median age was 66 years (range 33-96); 9/21 (43%) were <55 years. Regarding Cell of Origin DLBCL subtype, Germinal Center B-cell subtype was found in seven patients, non-GCB in 10 and non-classified in 4 patients. Median follow-up was 57 months and 5-year overall survival, lymphoma specific survival and Freedom from Progression were 78%, 89% and 90%, respectively. There was no correlation of patients' characteristics with survival parameters. Interestingly, none of the patients experienced CNS relapse. Our results indicate that localized FGT DLBCL exhibits a good prognosis and may not increase the risk for secondary CNS involvement.

Polatuzumab vedotin combined with bendamustine and rituximab for relapsed/refractory diffuse large B-cell lymphoma: A systematic review protocol.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin lymphoma subtype with a significant relapse rate and poor prognosis in relapsed/refractory (R/R) patients. Polatuzumab vedotin in combination with bendamustine and rituximab (Pola-BR) has demonstrated promising efficacy and safety as salvage therapy for R/R DLBCL. This systematic review protocol aims to comprehensively evaluate the efficacy of Pola-BR for the treatment of R/R DLBCL by synthesizing data from relevant randomized controlled trials. METHODS: This protocol details the eligibility criteria, search strategy, study selection, data extraction, and analysis methods for the systematic review. Randomized controlled trials comparing Pola-BR with other interventions for R/R DLBCL will be included. The primary endpoint is overall survival, with secondary endpoints being progression-free survival and incidence of adverse events. A comprehensive search will be conducted across databases such as Medline/PubMed, Cochrane Library, Web of Science, Scopus, EMBASE, ProQuest, EU Clinical Trials Register, WHO International Clinical Trials Registry Platform (ICTRP), and ClinicalTrials.gov from the January 2000 to April 2024. To assess the potential risk of bias, the Cochrane Risk of Bias 1 tool will be used. Data synthesis will utilize fixed-effect or random-effects models, and subgroup and meta-regression analyses will examine heterogeneity. Additionally, publication bias and sensitivity analyses will be performed, and the GRADE approach will be applied to assess the certainty of the evidence. CONCLUSION: This systematic review and meta-analysis protocol provides a rigorous framework for evaluating the efficacy of Pola-BR in the treatment of R/R DLBCL. The results will inform clinical decision-making and guideline development, addressing the unmet need for effective and tolerable treatments for this challenging patient population. Potential limitations and biases will be acknowledged, and future research directions will be discussed.

DNA mismatch repair defect and intratumor heterogeneous deficiency differently impact immune responses in diffuse large B-cell lymphoma.

Deficient (d) DNA mismatch repair (MMR) is a biomarker predictive of better response to PD-1 blockade immunotherapy in solid tumors. dMMR can be caused by mutations in MMR genes or by protein inactivation, which can be detected by sequencing and immunohistochemistry, respectively. To investigate the role of dMMR in diffuse large B-cell lymphoma (DLBCL), MMR gene mutations and expression of MSH6, MSH2, MLH1, and PMS2 proteins were evaluated by targeted next-generation sequencing and immunohistochemistry in a large cohort of DLBCL patients treated with standard chemoimmunotherapy, and correlated with the tumor immune microenvironment characteristics quantified by fluorescent multiplex immunohistochemistry and gene-expression profiling. The results showed that genetic dMMR was infrequent in DLBCL and was significantly associated with increased cancer gene mutations and favorable immune microenvironment, but not prognostic impact. Phenotypic dMMR was also infrequent, and MMR proteins were commonly expressed in DLBCL. However, intratumor heterogeneity existed, and increased DLBCL cells with phenotypic dMMR correlated with significantly increased T cells and PD-1+ T cells, higher average nearest neighbor distance between T cells and PAX5+ cells, upregulated immune gene signatures, LE4 and LE7 ecotypes and their underlying Ecotyper-defined cell states, suggesting the possibility that increased T cells targeted only tumor cell subsets with dMMR. Only in patients with MYC¯ DLBCL, high MSH6/PMS2 expression showed significant adverse prognostic effects. This study shows the immunologic and prognostic effects of genetic/phenotypic dMMR in DLBCL, and raises a question on whether DLBCL-infiltrating PD-1+ T cells target only tumor subclones, relevant for the efficacy of PD-1 blockade immunotherapy in DLBCL.

Transcriptomic classification of diffuse large B-cell lymphoma identifies a high-risk activated B-cell-like subpopulation with targetable MYC dysregulation.

Immunochemotherapy has been the mainstay of treatment for newly diagnosed diffuse large B-cell lymphoma (ndDLBCL) yet is inadequate for many patients. In this work, we perform unsupervised clustering on transcriptomic features from a large cohort of ndDLBCL patients and identify seven clusters, one called A7 with poor prognosis, and develop a classifier to identify these clusters in independent ndDLBCL cohorts. This high-risk cluster is enriched for activated B-cell cell-of-origin, low immune infiltration, high MYC expression, and copy number aberrations. We compare and contrast our methodology with recent DLBCL classifiers to contextualize our clusters and show improved prognostic utility. Finally, using pre-clinical models, we demonstrate a mechanistic rationale for IKZF1/3 degraders such as lenalidomide to overcome the low immune infiltration phenotype of A7 by inducing T-cell trafficking into tumors and upregulating MHC I and II on tumor cells, and demonstrate that TCF4 is an important regulator of MYC-related biology in A7.

KMT2D mutations promoted tumor progression in diffuse large B-cell lymphoma through altering tumor-induced regulatory T cell trafficking via FBXW7-NOTCH-MYC/TGF-ß1 axis.

Histone methyltransferase KMT2D is one of the most frequently mutated genes in diffuse large B-cell lymphoma (DLBCL) and has been identified as an important pathogenic factor and prognostic marker. However, the biological relevance of KMT2D mutations on tumor microenvironment remains to be determined. KMT2D mutations were assessed by whole-genome/exome sequencing (WGS/WES) in 334 patients and by targeted sequencing in 427 patients with newly diagnosed DLBCL. Among all 761 DLBCL patients, somatic mutations in KMT2D were observed in 143 (18.79%) patients and significantly associated with advanced Ann Arbor stage and MYC expression ≥ 40%, as well as inferior progression-free survival and overall survival. In B-lymphoma cells, the mutation or knockdown of KMT2D inhibited methylation of lysine 4 on histone H3 (H3K4), downregulated FBXW7 expression, activated NOTCH signaling pathway and downstream MYC/TGF-ß1, resulting in alterations of tumor-induced regulatory T cell trafficking. In B-lymphoma murine models established with subcutaneous injection of SU-DHL-4 cells, xenografted tumors bearing KMT2D mutation presented lower H3K4 methylation, higher regulatory T cell recruitment, thereby provoking rapid tumor growth compared with wild-type KMT2D via FBXW7-NOTCH-MYC/TGF-ß1 axis.

A Rare Case of Atrial Septal Mass Secondary to Lymphoma: Case Report and Review of Literature.

The antemortem diagnosis of secondary cardiac involvement by lymphoma remains suboptimal. Prognosis is worse with delayed diagnosis as the tumor burden increases with the multicompartment participation. Chemotherapy may improve survival, but there is a risk of mortality due to treatment-related complications, such as myocardial rupture and fatal arrhythmias. Modified chemotherapy regimens may prevent such complications, but the data are limited. We report the case of a 72-year-old woman diagnosed with diffuse large B-cell lymphoma with cardiac involvement, where early diagnosis prevented cardiac complications from the disease and its treatment as well. The aim of this case report is to highlight the fact that cardiac involvement in lymphoma is frequent and can be easily missed, leading to complications. Treatment requires an individualized approach.

TCP1 expression alters the ferroptosis sensitivity of diffuse large B-cell lymphoma subtypes by stabilising ACSL4 and influences patient prognosis.

Diffuse large B-cell lymphoma (DLBCL), an invasive lymphoma with substantial heterogeneity, can be mainly categorised into germinal centre B-cell-like (GCB) and non-GCB subtypes. DLBCL cells are highly susceptible to ferroptosis, which offers an effective avenue for treating recurrent and refractory DLBCL. Moreover, various heat shock proteins are involved in regulating the sensitivity of tumour cells to ferroptosis. Among these proteins, tailless complex polypeptide 1 (TCP1), a subunit of chaperonin-containing T-complex protein-1 (CCT), plays a role in tumour proliferation and survival. Therefore, we explored the role of TCP1 in different DLBCL subtypes, the sensitivity of GCB and non-GCB subtypes to the ferroptosis inducer RAS-selective lethal small molecule 3 (RSL3), and the underlying molecular mechanism. In GCB cells, TCP1 promoted RSL3-induced ferroptosis. Notably, TCP1 could bind with acyl-CoA synthetase long-chain family member 4 (ACSL4), a key enzyme regulating lipid composition and facilitating ferroptosis, to reduce its ubiquitination and degradation. This interaction activated the ACSL4/LPCAT3 signalling pathway and promoted ferroptosis in the GCB subtype. However, in the non-GCB subtype, TCP1 did not act as a positive regulator but served as a predictor of an unfavourable prognosis in patients with non-GCB. In conclusion, our results suggest that in DLBCL, high TCP1 expression enhances the sensitivity of GCB tumour cells to ferroptosis and serves as a marker of poor prognosis in patients with non-GCB DLBCL.

Inhibition of bromodomain and extra-terminal proteins targets constitutively active NFκB and STAT signaling in lymphoma and influences the expression of the antiapoptotic proteins BCL2A1 and c-MYC.

The antiapoptotic protein BCL2A1 is highly, but very heterogeneously expressed in Diffuse Large B-cell Lymphoma (DLBCL). Particularly in the context of resistance to current therapies, BCL2A1 appears to play an important role in protecting cancer cells from the induction of cell death. Reducing BCL2A1 levels may have therapeutic potential, however, no specific inhibitor is currently available. In this study, we hypothesized that the signaling network regulated by epigenetic readers may regulate the transcription of BCL2A1 and hence that inhibition of Bromodomain and Extra-Terminal (BET) proteins may reduce BCL2A1 expression thus leading to cell death in DLBCL cell lines. We found that the mechanisms of action of acetyl-lysine competitive BET inhibitors are different from those of proteolysis targeting chimeras (PROTACs) that induce the degradation of BET proteins. Both classes of BETi reduced the expression of BCL2A1 which coincided with a marked downregulation of c-MYC. Mechanistically, BET inhibition attenuated the constitutively active canonical nuclear factor kappa-light-chain-enhancer of activated B-cells (NFκB) signaling pathway and inhibited p65 activation. Furthermore, signal transducer of activated transcription (STAT) signaling was reduced by inhibiting BET proteins, targeting another pathway that is often constitutively active in DLBCL. Both pathways were also inhibited by the IκB kinase inhibitor TPCA-1, resulting in decreased BCL2A1 and c-MYC expression. Taken together, our study highlights a novel complex regulatory network that links BET proteins to both NFκB and STAT survival signaling pathways controlling both BCL2A1 and c-MYC expression in DLBCL.

Prediction of PD-L1 and Ki-67 status in primary central nervous system diffuse large B-cell lymphoma by diffusion and perfusion MRI: a preliminary study.

OBJECTIVE: To assess whether diffusion and perfusion MRI derived parameters could non-invasively predict PD-L1 and Ki-67 status in primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL). METHODS: We retrospectively analyzed DWI, DSC-PWI, and morphological MRI (mMRI) in 88 patients with PCNS-DLBCL. The mMRI features were compared using chi-square tests or Fisher exact test. Minimum ADC (ADCmin), mean ADC(ADCmean), relative minimum ADC (rADCmin), relative mean ADC (rADCmean), and relative maximum CBV (rCBVmax) values were compared in PCNS-DLBCL with different molecular status by using the Mann-Whitney U test. The diagnostic performances were evaluated by receiver operating characteristic curves. RESULTS: PCNS-DLBCL with high PD-L1 expression demonstrated a significantly higher ADCmin value than those with low PD-L1. The ADCmean and rADCmean values were significantly lower in PCNS-DLBCL with high Ki-67 status compared with those in low Ki-67 status. Other ADC, CBV parameters, and mMRI features did not show any association with these molecular statuses The diagnostic efficacy of ADC values in assessing PD-L1 and Ki-67 status was relatively low, with area under the curves (AUCs) values less than 0.7. CONCLUSIONS: DWI-derived ADC values can provide some relevant information about PD-L1 and Ki-67 status in PCNS-DLBCL, but may not be sufficient to predict their expression due to the rather low diagnostic performance.

TNFAIP3 Overexpression Inhibits Diffuse Large B-Cell Lymphoma Progression by Promoting Autophagy through TLR4/MyD88/NF-κB Signaling Pathway.

BACKGROUND: Tumor necrosis factor alpha induced protein 3 (TNFAIP3) is reportedly to have significant implications for autophagy regulation in various cancers. The current study aimed to decipher the role and mechanism of TNFAIP3 in diffuse large B-cell lymphoma (DLBCL) by modulating autophagy. METHODS: Information pertaining to the differential expression and prognostic role of TNFAIP3 in DLBCL was gleaned from the Gene Expression Omnibus (GEO) database. The TNFAIP3 expression levels in human DLBCL cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Cell counting kit-8 (CCK-8) and colony formation assays were employed to determine cell proliferation. Transwell assay and flow cytometry were applied to detect cell migration and apoptosis, respectively. Immunofluorescence and transmission electron microscope were used for the assessment of cell autophagy. The levels of apoptotic markers (caspase-3, cleaved-caspase-3, Bcl-2 Associated X (Bax), and B cell lymphoma-2 (Bcl-2)), autophagy indicators (the ratio of microtubule-associated proteins 1A/1B light chain 3 II and I (LC3II/LC3I), Sequestosome (p62)), and pathway proteins (toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), Transcription Factor NF-Kappa-B P65 Subunit (p65), and phosphorylated-p65 (p-p65)) were assessed via Western blotting. Immunohistochemistry was employed to detect Ki67 expression in tumor tissues. RESULTS: TNFAIP3 expression in DLBCL samples was downregulated, correlating with poor prognosis. TNFAIP3 expression was also downregulated in DLBCL cells. It was found that TNFAIP3 impeded cell proliferation and migration, and enhanced apoptosis of OCI-LY3 cells. Intervention with autophagy inhibitor 3-methyladenine (3-MA) markedly reversed apoptosis of OCI-LY3 cells induced by TNFAIP3. Besides, TNFAIP3 induced autophagy via modulating the TLR4/MyD88/nuclear factor kappa B (NF-κB) signaling pathway. In vivo experiments showed that TNFAIP3 expression in DLBCL was downregulated, and upregulation of TNFAIP3 could inhibit tumor growth. CONCLUSION: TNFAIP3 inhibits DLBCL progression by inducing TLR4/MyD88/NF-κB pathway-mediated autophagy.

Rupatadine-inhibited OTUD3 promotes DLBCL progression and immune evasion through deubiquitinating MYL12A and PD-L1.

The obstacle to effectively treating Diffuse Large B-cell Lymphoma (DLBCL) lies in the resistance observed toward standard therapies. Identifying therapeutic targets that prove effective for relapsed or refractory patients poses a significant challenge. OTUD3, a deubiquitinase enzyme, is overexpressed in DLBCL tissues. However, its role in DLBCL has not been investigated. Our study has brought to light the multifaceted impact of OTUD3 in DLBCL. Not only does it enhance cell survival through the deubiquitination of MYL12A, but it also induces CD8+ T cell exhaustion within the local environment by deubiquitinating PD-L1. Our findings indicate that the OTUD3 inhibitor, Rupatadine, exerts its influence through competitive binding with OTUD3. This operation diminishes the deubiquitination of both MYL12A and PD-L1 by OTUD3. This research unveils the central and oncogenic role of OTUD3 in DLBCL and highlights the potential clinical application value of the OTUD3 inhibitor, Rupatadine. These findings contribute valuable insights into addressing the challenges of resistant DLBCL cases and offer a promising avenue for further clinical exploration.

Multi-omics integration reveals the oncogenic role of eccDNAs in diffuse large B-cell lymphoma through STING signalling.

BACKGROUND: Extrachromosomal circular DNAs (eccDNAs), a type of double-stranded DNAs (dsDNAs) that facilitate the activation of the DNA sensing machinery, have been implicated in the progression and prognosis of various diseases. While the roles of eccDNAs remain contentious, their significance in diffuse large B-cell lymphoma (DLBCL) has not been reported. METHODS: Circular DNA sequencing (circle-seq) was used to demonstrate the expression profile of eccDNAs in DLBCL, and atomic force microscopy to validate the presence of eccDNAs. CCK-8 and scRNA-seq techniques were employed to uncover the activation of eccDNA in the STING pathway, leading to enhanced cell proliferation. Chemotherapeutic drugs were used to test the hypothesis that DNA damage induces the production of eccDNA, thereby activating the STING pathway independent of cGAS. GEO databases were used for verification of the prognosis of the eccDNA-related genes, and animal models were used to investigate the synergistic effects of DNA damage therapy in combination with STING inhibitors on anti-tumour responses. RESULTS: EccDNAs were widely expressed in DLBCL and associated with the prognosis of patients. Elevated abundance of eccDNAs promoted the progression of DLBCL. Chemotherapeutic drugs-induced DNA damage triggered the generation of eccDNAs, resulting in the activation of the STING signalling in a cGAS-independent manner. Moreover, inhibition of STING exerted a synergistic anti-tumour effect with cisplatin. CONCLUSIONS: EccDNAs induced by DNA damage exert an oncogenic role in DLBCL via activating the STING signalling independently of cGAS. This finding offers a rational therapeutic strategy combining chemotherapy with targeting STING. HIGHLIGHTS: EccDNAs induced by DNA damage exert an oncogenic role in DLBCL via activating the STING signalling independently of cGAS. The combined treatment of chemotherapeutic drugs with STING inhibitor significantly delayed the tumor progression, providing new insights into the therapeutic strategy for patients with DLBCL, particularly the relapsed and/or refractory (R/R) ones.

[Clinicopathological characteristics of angioimmunoblastic T-cell lymphoma with B-cell proliferation or neoplasms].

Objective: To investigate the clinical, pathological and immunophenotypic features, and differential diagnosis of angioimmunoblastic T-cell lymphoma (AITL) with B-cell proliferation or neoplasms. Methods: Eight qualified cases were collected from the Department of Pathology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China from January 2019 to July 2023. One case was diagnosed with AITL and diffuse large B-cell lymphoma (DLBCL) and the other seven cases were diagnosed with AITL and B-cell proliferation. Clinical characteristics and pathological morphology were summarized. Immunohistochemical analysis, fluorescence in situ hybridization and gene rearrangement detection were performed. Results: The patients' average age was 58 years. Five of them were male. Biopsies of the enlarged cervical lymph nodes showed structural destruction and exhibited various histologic patterns. Some cases revealed Burkitt-like morphology, a moderate tumor volume and slightly irregular nuclei. Some cases showed prominent nucleoli. High endothelial venules and expanded follicular dendritic cells were detected. Tumor cells derived from T-follicular helper (TFH) cells were positive for two or more TFH biomarkers. Nodular or diffuse patchy proliferation of B cells was noted around the tumor tissue, which was initially considered as B-cell lymphoma. All of the 8 cases showed monoclonal rearrangements of the T-cell receptor genes while 5 of them also showed clonal rearrangements of the Ig genes. Seven of the 8 cases were subject to the detection of C-MYC gene breakage and were all negative. EBV-positive cells were seen in 6 cases. Neoplastic B cells were positive for C-MYC (>40%), while proliferative B cells were negative for C-MYC (<40%). Conclusions: The histological morphology of AITL with B-cell proliferation or lymphoma may be different from AITL. An integrated analysis, incorporating clinical, morphologic, immunophenotypic, and molecular assessment, helps reach an accurate diagnosis. This group of cases demonstrated the clinical and pathological characteristics of AITL accompanied by B-cell proliferation and B-cell lymphoma. The findings suggest that C-MYC maybe a feasible indicator for distinguishing B-cell proliferation from B-cell lymphoma, and provide a simple and feasible immunohistochemical marker for the diagnosis and research of composite lymphoma.