Very old or frail patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) frequently cannot tolerate full-dose R-CHOP, and long-term control with R-miniCHOP is suboptimal. We assessed a sequential, chemotherapy-limiting regimen using zanubrutinib, lenalidomide, and rituximab (ZR2) induction followed by response-adapted ZR2-miniCHOP. This single-center, open-label, investigator-initiated phase 2 trial enrolled untreated patients aged ≥ 80 years, or 60–79 years with ECOG performance status ≥ 2. All patients received two 21-day cycles of chemotherapy-free ZR2 (zanubrutinib 160 mg twice daily continuously; lenalidomide 25 mg once daily on days 1–10; rituximab 375 mg/m2 on day 0), then four cycles of ZR2 plus reduced-dose miniCHOP. PET/CT after cycle 6 determined consolidation: two cycles of ZR2 maintenance for complete responders or two additional cycles of ZR2-miniCHOP for partial responders. Primary endpoints were overall response rate (ORR) and complete remission (CR) rate after six cycles; secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. Forty-eight patients were treated (median age 78 years; 45.8

BACKGROUND:Soft tissue sarcomas (STS) are a heterogeneous group of tumors with diverse clinical and molecular characteristics, characterized by limited treatment options and poor prognosis. Immune checkpoint inhibitors (ICIs) have emerged as promising therapies for STS, yet comprehensive evaluations of their efficacy, especially in combination with other treatments, are scarce. METHODS:We conducted a systematic review and meta-analysis of clinical trials on ICIs in STS treatment, sourced from PubMed, Embase, and the Cochrane Central Register of Controlled Trials up to May 31, 2024. The studies included both monotherapy and combination therapies with ICIs. We assessed the methodological quality using the Cochrane Risk of Bias 2 tool and the Methodological Index for Non-Randomized Studies. Data synthesis involved random-effects meta-analysis to determine pooled proportions and 95% confidence intervals (CIs) for objective response rates (ORR), disease control rates (DCR), and high-grade treatment-related adverse events (TRAEs). RESULTS:The analysis included 38 studies with 1349 patients covering 24 STS subtypes. The overall ORR was 16% (95% CI 0.12-0.21), DCR was 64% (95% CI 0.57-0.70), and the rate of Grade 3-5 TRAEs was 19% (95% CI 0.13-0.27). Treatments combining ICIs with tyrosine kinase inhibitors (TKIs) showed the highest efficacy (ORR 28%, 95% CI 0.18-0.40), albeit with increased adverse events. ORRs in first-line treatments were substantially higher (28%) compared to second-line treatments or beyond (11%). Subtypes like alveolar soft part sarcoma (ASPS), angiosarcoma (AS), and epithelioid sarcoma (ES) exhibited favorable responses exceeding 30%. CONCLUSIONS:This systematic review and meta-analysis indicate that ICIs, particularly when combined with TKIs, provide substantial therapeutic benefits in treating STS, significantly enhancing response rates in specific subtypes such as ASPS and AS. The results underscore the transformative potential of ICIs in STS treatment strategies. However, the variability across subtypes and treatment lines emphasizes the need for further randomized controlled trials to refine and personalize therapeutic approaches, ensuring optimal outcomes for patients with these diverse malignancies.

Epstein-Barr virus (EBV)-positive nodal T-cell and NK-cell lymphoma is a rare neoplasm of cytotoxic T-cell or NK-cell lineage. Here, we report 26 cases affecting 14 men and 12 women with a median age of 52 years. All patients presented with disease involving multiple lymph nodes, and 20 of 22 (91%) fully staged patients had advanced Ann Arbor stage disease. Spleen, liver, and bone marrow were involved in 70%, 50%, and 52% of cases, respectively. These patients had a dismal prognosis with a median survival of 30 days. Histologically, lymph nodes were replaced by lymphoma in a diffuse pattern. Lymphoma cells were variable in size and large cell morphology was seen in 62% of cases. The neoplastic cells were CD4-/CD8- in 14 (54%) cases and CD4-/CD8+ in 12 (46%) cases. CD56 was positive in 14 (54%) cases. CD30 was positive in 20 (77%) cases; a strong and diffuse pattern was observed in 14 (54%) cases, mimicking, in part, anaplastic large cell lymphoma (ALCL). CD30 expression was associated with younger age and large cell morphology. In summary, EBV+ nodal T-cell and NK-cell lymphoma is an aggressive disease with a poor prognosis. These neoplasms are heterogeneous at the morphologic and immunophenotypic levels. Diffuse and strong expression of CD30 could potentially lead to a misdiagnosis of ALCL if EBV evaluation is not performed. Distinguishing between EBV+ nodal T-cell and NK-cell lymphoma from ALCL is important because treatment strategy and prognosis differ. CD30 expression offers a potential therapeutic target for patients with this aggressive disease.

Introduction: Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare and highly aggressive disease that most reported in Asia. However, the specific mechanisms and factors within the tumor microenvironment (TME) that drive this malignant disease remain largely unknown. In this study, we performed a comprehensive analysis of TME in patients with MEITL by single-cell RNA sequencing and spatial transcriptomic, which might help further elucidate the tumor biology and gain an insight to treatments beyond chemotherapy and transplantation. Methods: A retrospective analysis of the clinical features and pathological data of 20 patients with MEITL treated at the First Affiliated Hospital of Zhejiang University School of Medicine from January 2019 to October 2023 was conducted. Four samples from 4 representative patients were subjected to single-cell RNA sequencing and spatial transcriptomic analysis. Results: Among the 20 patients with MEITL, there were 13 males and 7 females, with a median age of 55.2 (16-75) years. Nineteen cases (19/20) had lesions located in the jejunum or ileum. Abdominal pain, diarrhea, and fatigue were the main clinical symptoms, with intestinal perforation as the main complication. Immunohistochemistry results showed that most monomorphic epitheliotropic intestinal T-cell lymphoma tumor cells were positive for CD3 (20/20), CD8 (17/20), and CD56 (19/20) expression, while negative for CD5 (19/20) and EBER (18/20) expression. 17 patients died during follow-up due to disesae progression or infection secondary to interstital disease. The estimated one-year OS were 10%. Analysis of single-cell and spatial transcriptomic data revealed that various cells, including MEITL tumor cells, intestinal epithelial cells, and macrophages, were distributed in the intestinal pathological tissue. NK cells were absent among TEM of MEITL. The tumor cells maintain the phenotypes of both T and NK cells. There was a high degree of spatial correlation between tumor cells and macrophages. Further differential gene enrichment analysis of macrophages revealed a positive spatial correlation between tumor cells and M1 macrophages, while the numbers of M1 macrophages under high power field were also related to patients' survival. Conclusions: Monomorphic epitheliotropic intestinal T-cell lymphoma has an insidious onset, often presenting with acute abdomen, and has a very poor prognosis. According to single-cell sequencing and spatial transcriptomic results, the TME of MEITL is complex with various cells while in absence of NK cells. The high spatial correlation between tumor cells and macrophages suggests the underlying interactions of these two cells during the pathogenesis of MEITL.

Epstein-Barr virus (EBV)-positive nodal T-cell and NK-cell lymphoma is a rare neoplasm of cytotoxic T-cell or NK-cell lineage. Here, we report 26 cases affecting 14 men and 12 women with a median age of 52 years. All patients presented with disease involving multiple lymph nodes, and 20 of 22 (91%) fully staged patients had advanced Ann Arbor stage disease. Spleen, liver, and bone marrow were involved in 70%, 50%, and 52% of cases, respectively. These patients had a dismal prognosis with a median survival of 30 days. Histologically, lymph nodes were replaced by lymphoma in a diffuse pattern. Lymphoma cells were variable in size and large cell morphology was seen in 62% of cases. The neoplastic cells were CD4-/CD8- in 14 (54%) cases and CD4-/CD8+ in 12 (46%) cases. CD56 was positive in 14 (54%) cases. CD30 was positive in 20 (77%) cases; a strong and diffuse pattern was observed in 14 (54%) cases, mimicking, in part, anaplastic large cell lymphoma (ALCL). CD30 expression was associated with younger age and large cell morphology. In summary, EBV+ nodal T-cell and NK-cell lymphoma is an aggressive disease with a poor prognosis. These neoplasms are heterogeneous at the morphologic and immunophenotypic levels. Diffuse and strong expression of CD30 could potentially lead to a misdiagnosis of ALCL if EBV evaluation is not performed. Distinguishing between EBV+ nodal T-cell and NK-cell lymphoma from ALCL is important because treatment strategy and prognosis differ. CD30 expression offers a potential therapeutic target for patients with this aggressive disease.

Eosinophilia may result from three main causes: secondary (reactive), primary (clonal), and/or idiopathic. The diagnosis of idiopathic eosinophilia must be made based on excluding all reactive or clonal causes. However, some causes may be very rare so as to be misdiagnosed as idiopathic. We present the case of eosinophilia caused by aggressive systemic mastocytosis, originally recognized as idiopathic. Lymphadenopathy, dysmyelopoiesis, and hepatosplenomegaly gradually appeared and deteriorated with increasing eosinophils. This case carried KIT D816V mutation. The BCR::ABL fusion gene and the mutations in JAK2 V617F, PDGFRα, and PDGFRβ in bone marrow were all negative. PHF6, PPM1D, and TET2 mutations were demonstrable. The patient was prescribed to avapritinib. The condition was effectively controlled. However, the patient discontinued medication for economic reasons 5 months later. Disease progression happened and died 10 months after diagnosis. Our study indicates that gene mutation detection at diagnosis is helpful for patient accurate diagnosis and targeted therapy of such patients.

Eosinophilia may result from three main causes: secondary (reactive), primary (clonal), and/or idiopathic. The diagnosis of idiopathic eosinophilia must be made based on excluding all reactive or clonal causes. However, some causes may be very rare so as to be misdiagnosed as idiopathic. We present the case of eosinophilia caused by aggressive systemic mastocytosis, originally recognized as idiopathic. Lymphadenopathy, dysmyelopoiesis, and hepatosplenomegaly gradually appeared and deteriorated with increasing eosinophils. This case carried KIT D816V mutation. The BCR::ABL fusion gene and the mutations in JAK2 V617F, PDGFRα , and PDGFRβ in bone marrow were all negative. PHF6, PPM1D , and TET2 mutations were demonstrable. The patient was prescribed to avapritinib. The condition was effectively controlled. However, the patient discontinued medication for economic reasons 5 months later. Disease progression happened and died 10 months after diagnosis. Our study indicates that gene mutation detection at diagnosis is helpful for patient accurate diagnosis and targeted therapy of such patients. Keywords Aggressive systemic mastocytosis , D816V mutation , avapritinib , eosinophilia , case report

As a rare lymphoproliferative disorder, many patients with HHV-8/HIV-negative Castleman disease (CD) have hypoalbuminemia. However, data is limited on whether hypoalbuminemia is an independent predictor of CD. We retrospectively collected data from 230 patients diagnosed at 12 medical centers in China and the U.S. Different classifications included 147 patients with unicentric CD (UCD) and 83 with idiopathic multicentric CD (iMCD). Adjusted smooth curve fitting showed that the relationship between albumin and all-cause death of patients with CD and iMCD was linear. Cox proportional hazards regression modeling showed a negative association between the risk of death and albumin level (hazard ratio [HR]: 0.84; 95% CI, 0.76, 0.93). Using the Kaplan-Meier method, we determined that hypoproteinemia was a risk factor for poorer prognosis in patients with CD, UCD, and iMCD. Albumin was independently and negatively associated with the risk of death in CD patients, especially those with iMCD.

Objective: To study the relationship between the onco-immunological and morphologic characteristics of lymphoepithelioma-like carcinoma (LELC) and peripheral blood lymphocyte subtypes and its clinical significance. Methods: The pathologic and clinical data of 117 LELC patients who were admitted to the Tumor Hospital of the University of Chinese Academy of Sciences from 2006 to 2018 were collected. The histological classification was based on previously reported morphological classification method. The onco-immunological and morphologic characteristics of the tumors such as lymphoid follicle formation and interstitial fibrous hyperplasia, patient's peripheral blood lymphocyte subtypes and prognosis data were collected. The relationship between various factors and their impact on prognosis were analyzed. Results: There were 117 patients, including 61 females and 56 males. The male to female ratio was 0.9∶1.0. The age of onset was 24-89 years (median 52 years). Primary sites included head and neck (68 cases), lungs (26 cases), stomach (15 cases), and others (eight cases). Morphologically, 54 cases were type Ⅰ, 62 cases were type Ⅱ, and one case could not be classified. The onco-immunological and morphologic features of the LELC tumors showed a continuous spectrum. Interstitial TILs were noted from focally to diffuse, and the interstitial fibrous tissues were from hardly visible to obvious sclerotic. Formation of lymphoid follicles was seen in 42 patients; obvious fibrosis was seen in 31 cases. Data of peripheral blood lymphocyte subtyping by flow cytometry were available in 73 cases. These data included CD3+total T cells, CD3+CD4+helper T cells, CD3+CD8+cytotoxic T cells, CD3-CD56+natural killer (NK) cells, CD3-CD19+B cells, CD4+CD45RA-T helper induction subgroup, CD4+CD45RA+ T suppression induction subgroup, CD4+CD45RO+memory T cell subgroup, CD45RA+CD45RO+activated T cell subgroup, CD8+CD38+activated cytotoxic T cell, and CD25+lymphocytes and CD44+lymphocyte. The proportion of lymphocytes of each subtype was normal in most patients, but the proportion of CD44+lymphocytes in 61 cases (83.6%) was increased; the proportion of T cell suppression induced subgroups was decreased in 53 cases (72.6%). Correlation analysis found a significant correlation between clinical stage and NK cells (P=0.023); tumor histologic type and cytotoxic T cells were significantly positively correlated (P=0.012); while tumor cell morphologic differentiation was significantly related to total T cells (P=0.003) and NK cells (P=0.026); Formation of interstitial lymphoid follicles was positively correlated with memory T cell subsets (P=0.025); Tumor interstitial fibrosis was significantly positively correlated with T suppression-induced subpopulations (P=0.004), and was significantly negatively correlated with total T cells (P=0.023) and with the expression of CD44 adhesion molecules (P=0.003). Survival analysis found that lymphoid follicle formation was a favorable prognostic factor for LELC (P=0.001). Conclusions: The onco-immunological and morphologic features in LELC show a continuous spectrum; the tumor clinicopathological characteristics and onco-immunological morphology are closely related to peripheral blood T lymphocyte subtypes, and the formation of interstitial lymphoid follicles is a favorable prognostic factor for LELC.

BACKGROUND:Burkitt-like lymphoma with 11q aberration (BLL-11q) is a rare provisional lymphoma, and the majority of cases are usually diagnosed by excisional lymph node biopsy. Here we report a case of BLL-11q diagnosed by needle biopsy of the liver in order to improve further understanding of the disease, reduce misdiagnosis, and identify treatment regimens.CASE SUMMARY:The patient was a 67-year-old male. He complained of increased frequency of stools for more than one year, periumbilical pain and discomfort exceeding 3 mo. A computed tomography scan suggested an appendiceal malignant tumor with multiple metastases of the peritoneum, omentum, and liver. Needle biopsy of liver nodules showed that the tumor cells were of median size, the shape was consistent, a small number of tumor cells were large, the "starry sky" pattern was evident, and some tissue cells showed multiple apoptotic debris with coarse particles. Immunohistochemistry was positive for CD20, CD10, BCL6, and MYC. The Ki-67 proliferation index was more than 95%. Molecular biological detection indicated a lack of MYC, BCL2 and BCL6 gene rearrangement with 11q aberration. Therefore, the diagnosis was BLL-11q of the liver. After eight courses of chemotherapy, the abdominal and pelvic peritoneal masses and liver nodules had almost disappeared. The patient recovered well after a follow-up period of more than 13 mo.CONCLUSION:BLL-11q is rare, but patients treated with standard chemotherapy for Burkitt lymphoma can have a good prognosis. Reducing the dose of chemotherapy or developing specific therapies to prevent overtreatment may be considered, but more case studies are needed.

Castleman disease (CD) has been reported as a group of poorly understood lymphoproliferative disorders, including unicentric CD (UCD) and idiopathic multicentric CD (iMCD) which are human immunodeficiency virus (HIV) negative and human herpes virus 8 (HHV-8) negative. The clinical and independent prognostic factors of CD remain poorly elucidated. We retrospectively collected the clinical information of 428 patients with HIV and HHV-8 negative CD from 12 large medical centers with 15-year follow-up. We analyzed the clinicopathologic features of 428 patients (248 with UCD and 180 with iMCD) with a median age of 41 years. The histology subtypes were hyaline-vascular (HV) histopathology for 215 patients (56.58%) and plasmacytic (PC) histopathology for 165 patients (43.42%). Most patients with UCD underwent surgical excision, whereas the treatment strategies of patients with iMCD were heterogeneous. The outcome for patients with UCD was better than that for patients with iMCD, 5-year overall survival (OS) rates were 95% and 74%, respectively. In further analysis, a multivariate analysis using a Cox regression model revealed that PC subtype, hepatomegaly and/or splenomegaly, hemoglobin ≤ 80 g/L, and albumin ≤ 30 g/L were independent prognostic factors of CD for OS. The model of iMCD revealed that age > 60 years, hepatomegaly and/or splenomegaly, and hemoglobin ≤ 80 g/L were independent risk factors. In UCD, single-factor analysis identified two significant risk factors: hemoglobin ≤ 100 g/L and albumin ≤ 30 g/L. Our study emphasizes the distinction of clinical characteristics between UCD and iMCD. The importance of poor risk factors of different clinical classifications may direct more precise and appropriate treatment strategies.

Exuberant large T-cell proliferations in Kikuchi disease can potentially be misdiagnosed as lymphoma. In this study, we explore their clinicopathological features and summarize key points that can be used to distinguish them from T-cell lymphoma. The cohort consisted of 25 cases of Kikuchi disease with an exuberant large T-cell proliferation, which, in part, mimicked lymphoma. The median age was 25 years with a female:male ratio of 4:1. By B-scan ultrasonography, patients presented with either isolated lymphadenopathy (68%) involving the cervical and axillary regions or generalized lymphadenopathy (32%). Histologically, lymph nodes showed paracortical and interfollicular expansion by sheets of large cells associated with karyorrhectic debris. Histiocytes and plasmacytoid dendritic cells were present in the background. No case showed complete effacement of lymph node architecture. The large cells were CD8-positive cytotoxic T-cells with a high proliferation rate. These T-cells showed decreased BCL-2 in 17 (68%) cases. CD5 expression was decreased in 10 (40%) cases. Histiocytes in the background were positive for myeloperoxidase. Clonal TRG and/or TRB rearrangements were detected in 2 of 10 (20%) cases. In conclusion, large T-cell proliferations in Kikuchi disease can be alarming at the morphologic and immunophenotypic levels and need to be distinguished from T-cell lymphoma. Clinical features helpful in the differential diagnosis include young patients and lymphadenopathy involving the cervical and axillary regions. Major pathologic features helpful in this differential diagnosis include partial involvement of the lymph node and the presence of karyorrhectic debris, crescent-shaped histiocytes, and/or loose aggregates of plasmacytoid dendritic cells.

Background Large B-cell lymphoma (LBCL) with interferon regulatory factor 4 (IRF4) rearrangement (LBCL-IRF4) is a rare entity of LBCL with a specific clinical presentation. Notably, it is defined by the presence of an IRF4 rearrangement. Case presentation Here, we describe a case of a 2-years-old child presenting with a LBCL-IRF4 located in the left tonsil, with characteristic histologic appearance and the phenotype of neoplastic cells. The histologic analysis showed the monomorphic atypical lymphoid cells were medium size or large, positive for CD20, CD79a, MUM-1, GATA3, and Ki-67 was about 80%; Fluorescence in situ hybridization (FISH) analysis confirmed the presence of an IRF4 rearrangement. The patient was followed up for 18 months with no evidence of recurrence after being treated with 1 cycles of R-CHOP. Conclusion Morphologically, LBCL-IRF4 has predominantly diffuse or follicular pattern with a large number of necrosis, and a high proliferation rate, all of these suggest that the tumor is highly invasive. But actually LBCL-IRF4 usually performs a favorable outcome after therapy. Furthermore, LBCL-IRF4 with GATA3 positive have never been reported.

Abstract Angioimmunoblastic T cell lymphoma (AITL) is a unique subtype of peripheral T cell lymphoma (PTCL). Studies have shown that RHOA p. Gly17Val mutations contribute to the specific pathogenesis of AITL. Here we reported a case of AITL with a novel RHOA mutation encoding p. Ala161Glu. This case presented with persistent hypereosinophilia for more than 3 years prior to diagnosis. At the time of diagnosis, the patient manifested with B symptoms, multiple lymphadenopathies, liver and spleen involvement. A retrospective analysis of whole exome sequencing and digital PCR of previous pathological specimens at different periods showed that RHOA p. Ala161Glu mutation and TP53 mutation occurred simultaneously. RHOA p. Ala161Glu mutation was found to be less frequent or undetectable in early gastrointestinal tract and lymph nodes. In the intestine, lymph nodes and other involved tissues, it increased with the progression of the disease. Notably, it was significantly elevated at the time of diagnosis. We presumed that the RHOA p. Ala161Glu mutation might be related to AITL pathogenesis. However, it needs further study to identify the specificity of RHOA p. Ala161Glu mutation in AITL.

伴PDGFRA、PDGFRB或FGFR1重排或PCM1-JAK2及嗜酸性粒细胞增多的髓系/淋系肿瘤，是2016版WHO淋巴造血系统肿瘤分类中的独立疾病类型。在这一类别中，共同的特征是融合基因的形成导致异常酪氨酸激酶的表达。其中，伴有PDGFRA重排的髓系/淋系肿瘤是最常见的肿瘤类型。现报道1例罕见的以T淋巴母细胞性淋巴瘤为初始表现，并伴PDGFRA重排的髓系/淋系肿瘤。

Myelodysplastic syndrome with myelofibrosis (MDS-MF) has been associated with an inferior prognosis compared with MDS without MF. However, MDS-MF is not listed independently as a subtype of MDS, and its clinical and genetic characteristics remain poorly understood. We retrospectively compared 53 patients with MDS-MF (44 MF grade 1/MF 1 ; 9 MF grade 2–3/MF 2 − 3 ) and 31 with de novo MDS without MF (MDS). The leukemic transformation risks of both MDS-MF 2 − 3 and MDS-MF 1 were increased compared with the MDS group. To identify the potential mechanisms responsible for the leukemic transformation of MDS-MF, we performed single-cell sequencing for one MDS-MF 2 − 3 patient before and after leukemic transformation to explore the variations in gene expression levels. In addition to upgraded expression levels of acute myeloid leukemia-related genes during leukemic transformation, expression levels of some inflammation-related genes (such as S100s , RNASE3 , and CYBB ) were also increased, and inflammation-related pathways were up-regulated. These results suggest that inflammation-related genes and pathways may play an important role in the leukemic transformation of MDS-MF.

Histiocytic/dendritic cell tumors are rare in clinical practice. It is postulated that they originate from bone marrow stem cells. Accumulating evidence has established the existence of immunoglobulin gene and T-cell receptor gene rearrangements in these tumors. Cases of transdifferentiation across lineages from follicular lymphoma to histiocytic/dendritic cell tumors have also been reported. Herein, we report 2 adult males with histiocytic neoplasms coexisting with B-cell lymphoma. Laser capture microdissection and capillary electrophoresis polymerase chain reaction analysis revealed comparable immunoglobulin gene rearrangement in both patients. In one case, chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), Langerhans cell sarcoma, and histiocytic sarcoma coexisted in the lymph nodes. 11q22 deletion often present in CLL/SLL and expression of the BRAF V600E gene was detected in all the 3 components. In the other case, there diffuse large B-cell lymphoma and histiocytic sarcoma coexisted in the spleen. Forty-seven mutated genes commonly found in B-cell lymphoma were detected by next-generation sequencing. In the same line, DTX1, IRF8, KMT2D, MAP2K1, and TET2 genes were found to have similar mutation sites. The results of this study will contribute in providing new ideas for targeted treatment of these diseases.

Background Large B-cell lymphoma (LBCL) with interferon regulatory factor 4 (IRF4) rearrangement (IRF4+LBCL) is a rare and newly discovered subtype of mature B cell neoplasms. Case presentation Here, we describe a patient of 32 years old who was diagnosed IRF4+LBCL. Histological examination showed the normal structure of the lymphoid tissues were destroyed, and slightly crowded follicular or nodal structures instead. There were obvious necrosis on the surface of tonsil and the central part of some follicles. The monomorphic atypical lymphoid cells proliferated and grew consistently, which were of medium size or large, and the nuclear chromatin was opening. Some tumor cells can be seen around the normal striated muscle tissues near the tonsils. Immunohistochemistry (IHC) could show that CD20, CD79a, MUM-1 and BCL6 were positive, Ki-67 was 80%; CD3, CD5, CD10, BCL2, CD30, CD56, CD99, CD38, and CD138 were negative. In situ hybridization (ISH) of EBER was negative. Fluorescence in situ hybridization (FISH) confirmed that IRF4 gene rearrangement was found in tumor cells. The patient was followed up for 18 months without tumor after chemotherapy. Conclusion Generally speaking, destructive growth patterns with a large number of necrosis, high proliferation index and so on all suggest that the tumor is highly invasive. And in terms of pathological morphology, IRF4+LBCL can be similar to both high-grade follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). But actually this disease is indolent and significantly different.

Background：Primary cardiac CD5 positive diffuse large B-cell lymphoma (CD5+ DLBCL) is a rare subtype of DLBCL with many diagnostic challenges. The case is reported, along with a review of several characteristics of the disease. Case presentation：We described a 64-year-old female who presented with a 12-month history of cough, and a mass in the right atrium observed on imaging studies that extended into the right ventricle. Conclusions：CD5+ DLBCL was confirmed finally by pathological examination of the cardiac biopsy. The patient responded well to the modified R-CHOP regime. The poor prognosis factors include CD5 positive, non-GCB immunophenotype, myc, bcl-2 and bcl-6 gene rearrangements etc. Early diagnosis and aggressive treatment play a key role on improving the prognosis of primary cardiac CD5+ DLBCL.