Objective:To analyze the factors affecting delayed chemotherapy in children with Burkitt lymphoma (BL) and their influence on prognosis.Methods:Retrospective cohort study. Clinical data of 591 children aged ≤18 years with BL from May 2017 to December 2022 in China Net Childhood Lymphoma (CNCL) was collected. The patients were treated according to the protocol CNCL-BL-2017. According to the clinical characteristics, therapeutic regimen was divided into group A, group B and group C .Based on whether the total chemotherapy time was delayed, patients were divided into two groups: the delayed chemotherapy group and the non-delayed chemotherapy group. Based on the total delayed time of chemotherapy, patients in group C were divided into non-delayed chemotherapy group, 1-7 days delayed group and more than 7 days delayed group. Relationships between delayed chemotherapy and gender, age, tumor lysis syndrome before chemotherapy, bone marrow involvement, disease group (B/C group), serum lactate dehydrogenase (LDH) > 4 times than normal, grade Ⅲ-Ⅳ myelosuppression after chemotherapy, minimal residual disease in the interim assessment, and severe infection (including severe pneumonia, sepsis, meningitis, chickenpox, etc.) were analyzed. Logistic analysis was used to identify the relevant factors. Kaplan-Meier method was used to analyze the patients' survival information. Log-Rank was used for comparison between groups.Results:Among 591 patients, 504 were males and 87 were females, the follow-up time was 34.8 (18.6,50.1) months. The 3-year overall survival (OS) rate was (92.5±1.1)%,and the 3-year event-free survival (EFS) rate was (90.5±1.2)%. Seventy-three (12.4%) patients were in delayed chemotherapy group and 518 (87.6%) patients were in non-delayed chemotherapy group. The reasons for chemotherapy delay included 72 cases (98.6%) of severe infection, 65 cases (89.0%) of bone marrow suppression, 35 cases (47.9%) of organ dysfunction, 22 cases (30.1%) of tumor lysis syndrome,etc. There were 7 cases of chemotherapy delay in group B, which were seen in COPADM (vincristine+cyclophosphamide+prednisone+daunorubicin+methotrexate+intrathecal injection,4 cases) and CYM (methotrexate+cytarabine+intrathecal injection,3 cases) stages. There were 66 cases of chemotherapy delay in group C, which were common in COPADM (28 cases) and CYVE 1 (low dose cytarabine+high dose cytarabine+etoposide+methotrexate, 12 cases) stages. Multinomial Logistic regression analysis showed that the age over 10 years old ( OR=0.54,95% CI 0.30-0.93), tumor lysis syndrome before chemotherapy ( OR=0.48,95% CI 0.27-0.84) and grade Ⅲ-Ⅳ myelosuppression after chemotherapy ( OR=0.55,95% CI 0.33-0.91)were independent risk factors for chemotherapy delay.The 3-year OS rate and the 3-year EFS rate of children with Burkitt lymphoma in the delayed chemotherapy group were lower than those in the non-delayed chemotherapy group ((79.4±4.9)% vs. (94.2±1.1)%, (80.2±4.8)% vs. (92.0±1.2)%,both P<0.05). The 3-year OS rate of the group C with chemotherapy delay >7 days (42 cases) was lower than that of the group with chemotherapy delay of 1-7 days (22 cases) and the non-delay group (399 cases) ((76.7±6.9)% vs. (81.8±8.2)% vs. (92.7±1.3)%, P=0.002).The 3-year OS rate of the chemotherapy delay group (9 cases) in the COP (vincristine+cyclophosphamide+prednisone) phase was lower than that of the non-chemotherapy delay group (454 cases) ((66.7±15.7)% vs. (91.3±1.4)%, P=0.005). Similarly, the 3-year OS rate of the chemotherapy delay group (11 cases) in the COPADM1 phase was lower than that of the non-chemotherapy delay group (452 cases) ((63.6±14.5)% vs. (91.5±1.3)%, P=0.001). Conclusions:The delayed chemotherapy was related to the age over 10 years old, tumor lysis syndrome before chemotherapy and grade Ⅲ-Ⅳ myelosuppression after chemotherapy in pediatric BL. There is a significant relationship between delayed chemotherapy and prognosis of BL in children.

To investigate the clinical and pathological characteristics of duodenal-type follicular lymphoma (D-FL), and to deepen the understanding of Duodenal-type follicular lymphoma. The clinical symptoms, endoscopic features, pathologic features, immunophenotype, molecular pathological features and treatment follow-up of 18 D-FL patients diagnosed in Department of Pathology, Beijing Tiantan Hospital affiliated to Capital Medical University between January 2020 and July 2023 were summarized. A total of 18 patients with D-FL were included, including 10 males and 8 females. The median age was 49 (32-69) years respectively. Most of the patients were found during gastroenteroscopy or presented with the common gastrointestinal symptoms of stomach pain, acid reflux, vomiting and diarrhea. Most endoscopic findings were multiple small gray and white polyposis. In the pathological morphology, the mucous layer and submucous layer showed lymphoid follicular structures with full and strained follicles. The immunophenotype showed that the tumor cells strongly expressed CD20 and BCL2 and had low proliferation activity. Immunoglobulin clonal analysis of 1 case showed IgK monoclonal rearrangement (1/1). FISH showed 1 case of BCL2 gene rearrangement (1/3). All patients did not receive targeted chemotherapy and adopted a wait-and-see strategy. Median follow-up was 12 (2-34) months. This study shows that D-FL is an indolent lymphoma, which tends to occur in the duodenum and has a good prognosis.

Objective:To investigate the clinicopathological and molecular genetic characteristics and prognosis of patients with diffuse large B-cell lymphoma (DLBCL).Methods:The clinicopathological data of 152 DLBCL patients receiving consultation and routine physical examination in Peking University Third Hospital and Peking University School of Basic Medicine from January 2008 to December 2015 were retrospectively analyzed. Immunohistochemistry was used to detect the expressions of CD10, bcl-6, MUM1, GCET1, FOXP1. EB virus encoded small RNA (EBV-EBER) was detected by using in situ hybridization. The aberrations of bcl-2, bcl-6 and c-myc genes were detected by using fluorescence in situ hybridization (FISH) to screen double-hit lymphoma (DHL). Kaplan-Meier method was used to make survival analysis.Results:Among 152 cases of DLBCL, the ratio of male to female was 1.49:1, the median age of onset was 59 years (7-90 years), and 79 cases (52.0%) were primary lymph nodes. The median overall survival (OS) time of all cases was 16 months (1-101 months). The 1-year, 3-year and 5-year OS rates were 70.2%, 44.7%, 30.3%, respectively. The OS of R-CHOP treatment group was better than that of CHOP treatment group and untreated group ( P = 0.001). Among all 137 patients receiving double-hit histochemistry score (DHS), there were 56 cases with 0 score, 57 cases with 1 score, 24 cases with 2 scores; and the difference in the OS of different DHS score groups ( P = 0.311). FISH detection showed that among 29 cases achieving results of c-myc gene detection, there were 2 cases of splitting gene and 3 cases of gene amplification; among 26 cases achieving results of bcl-2 gene detection, 2 cases had bcl-2 gene amplification; among 26 cases achieving results of bcl-6 gene detection, 2 cases had bcl-6 gene amplification and 3 cases had splitting gene. It was found that myc and bcl-2 genes were amplified simultaneously in 1 case, accompanied with bcl-6 gene splitting, which was called triple-hit lymphoma. In DHS 0-score group, 1 case of double gene abnormality was found, and 1 case of single gene abnormality was found in group 1-score; in group 2-score, 5 cases were single gene abnormality and 1 case was three gene abnormality, so the gene abnormality was inconsistent with the protein expression. Conclusions:The incidence of DHL in DLBCL patients in China is low. The major gene abnormalities are c-myc or bcl-2, bcl-6 single gene abnormalities.

Molecular typing of leukemia is the basis of risk assessment and treatment options. NUTM1 gene (15q14) rearrangement is a novel molecular type of acute B lymphoblastic leukemia (B-ALL), which is mainly found in children (≥1 year old) and infants (< 1 year old). The number of patients is slightly more in children than infants. However, in infantile ALL, NUTM1 rearrangement is the second most common molecular abnormality. These children respond well to conventional chemotherapy regimens and with a good prognosis. The number of leukemia patients with NUTM1 gene rearrangement is still small, and there is no relevant study or case report in China. NUT protein encoded by NUTM1 gene is a chromatin regulator, which is related to histone acetylation regulation and chromatin remodeling. This article aims to introduce the clinicopathological features, detection methods, possible tumorigenic mechanisms and therapeutic prospects of leukemia with NUTM1 gene rearrangement, to increase the understanding of this type of leukemia and provide reference for the precise molecular subtyping and treatment.

Objective:To explore the feasibility of predicting TP53 mutation risk by immunohistochemical staining (IHC) pattern of P53 in Chinese diffuse large B-cell lymphoma (DLBCL) and its correlation with a prognostic difference.Methods:Between January 2021 and December 2021, 51 DLBCL cases at Beijing Boren Hospital were gathered. These cases had both IHC and next-generation sequencing (NGS) results. IHC classified the P53 protein expression pattern into a loss (<1% ) , diffuse (>80% ) , and heterogeneous (1% -80% ) . The sensitivity and specificity of the predicting TP53 mutation by IHC were assessed by comparing the results of the NGS, and the TP53 high mutation risk group included both loss and diffuse expression of P53. From June 2016 to September 2019, Peking University Cancer Hospital collected 131 DLBCL cases with thorough clinicopathological and follow-up data. From their tumor blocks, tissue microarray blocks were made for IHC evaluation of P53 expression pattern, and prognosis effect of P53 studies.Results:Among 51 cases with both IHC and NGS results, 23 cases were classified as TP53 high mutation risk (7 cases loss and 16 cases diffuse) , 22/23 cases were proved with mutated TP53 by NGS. Only 1 of the 28 cases classified as TP53 low mutation risk was proved with mutated TP53 by NGS. IHC had a sensitivity and specificity of 95.7% and 96.4% for predicting TP53 mutation. NGS identified a total of 26 TP53 mutations with a mutation frequency of 61.57% (13.41% -86.25% ) . In the diffuse group, 16 missense mutations and 2 splice mutations were detected; 6 truncating mutations and 1 splice mutation were detected in the loss group; 1 truncating mutation was detected in the heterogeneous group. Multivariate analysis demonstrated that TP53 cases with high mutation risk have impartial adverse significance for the 131 patients included in survival analysis ( HR=2.612, 95% CI 1.145-5.956, P=0.022) . Conclusion:IHC of P53 exhibiting loss (<1% ) or diffuse (>80% ) pattern indicated TP53 high mutation risk, IHC can predict TP53 mutation with high specificity and sensitivity. TP53 high mutation risk is an independent predictor for adverse survival.

Objective:To explore the clinical application of NanoString fluorescent barcode technology in the molecular subtyping of diffuse large B-cell lymphoma (DLBCL), and to analyze the correlation between the cell-of-origin subtype and prognosis of patients.Methods:The tumor tissue samples of 12 patients with DLBCL at the Third People's Hospital of Datong of Shanxi Province and 8 patients with DLBCL at Peking University, Health Science Center between January 2014 and December 2019 were collected. According to Hans algorithm, all patients were divided into 1 case of germinal center-derived B-cell (GCB) type and 19 cases of non-GCB type. NanoString platform was used to analyze the expression level differences of 15 genes-related to Lymph2Cx molecular subtyping of all samples at mRNA level. Hierarchical clustering was used to subgroup 20 DLBCL cases and to contrast the prognosis in different subgroups according to the subtyping.Results:NanoString fluorescent barcode technology was used to detect samples of 20 DLBCL cases and hierarchical clustering analysis was performed, and then subtyping results showed that 11 cases were GCB-like type and 9 cases were activated B cell (ABC)-like type. Based on Hans algorithm, 10 GCB-like cases were non-GCB type. According to the survival analysis, GCB-like group had a better overall survival compared with that in ABC-like group ( P=0.019). Conclusion:NanoString fluorescent barcode technology can be successfully applied to the cell-of-origin subtyping of DLBCL, and the molecular subtyping strategy can effectively predict the prognosis of patients.

Objective:To investigate the incidence of high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangement in Chinese diffuse large B-cell lymphoma (DLBCL) .Methods:From January 2013 to August 2020, 922 DLBCL cases were collected. C-MYC and BCL2 protein expression levels were analyzed by immunohistochemistry staining. Fluorescence in situ hybridization was used to detect the structural abnormalities of MYC, BCL2, and BCL6, including gene breaks and copy number changes.Results:MYC and BCL2 and/or BCL6 gene breaks were found in 29 out of 922 DLBCL cases (3.15%) , including 25 cases of double-hit lymphoma (DHL; 14 cases involving MYC and BCL2 rearrangements and 11 cases involving MYC and BCL6 rearrangements) and four cases involving MYC, BCL2, and BCL6 rearrangements, referring to triple-hit lymphoma. According to the threshold of C-MYC ≥40% and BCL2 ≥50%, 541 cases (58.68%) overexpressed C-MYC and BCL2 proteins, including 22 DHL cases. Moreover, according to the threshold of C-MYC ≥70% and BCL2 ≥50%, 52 cases (5.64%) overexpressed C-MYC and BCL2 proteins, including nine DHL cases. The P53 protein expression was detected by immunohistochemistry staining. The mutant P53 expression pattern was shown in 101 out of 709 cases (14.25%) , whereas 13 cases (1.83%) were negative, likely indicating P53 gene fragment deletion.Conclusion:The incidence of high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements was low in DLBCLs, and no significant correlation between gene abnormality and protein overexpression was shown. The correct diagnosis of DHL depends on molecular genetic detection.

Objective:To explore the key points of the pathological and differential diagnoses of extra-medullary masses of hematopoietic cell tumors of ambiguous lineage, and to discuss the possible solutions.Methods:Five hematopoietic cell tumors of ambiguous lineage cases were collected, including myeloid sarcoma, mixed phenotype acute leukemia, B/myeloid, T-lymphoblastic lymphoma combined with acute myeloid leukemia, acute undifferentiated leukemia with cutaneous MPDCP and early T-precursor cell acute lymphoblastic leukemia. The data including morphology, immunostaining, and flow cytometry analysis were collected, and we explored the problems and differential diagnosis in the diagnosis of hematopoietic cell tumors of ambiguous lineage.Results:The five cases showed that the accurate pathological diagnosis and classification of hematopoietic cell tumors of ambiguous lineage should be based on lineage-specific antigens. Moreover, tumor cells have the potential of multi-directional differentiation. In different sites or different periods, the differentiation of tumor cells may be different. Biopsy and detection of all related markers should be performed for the initial diagnosis, and the detection should be repeated when the condition of the patient changes. Combined application of multi-techniques, including morphology and flow cytometry analysis, is recommend for the diagnosis of hematopoietic cell tumors of ambiguous lineage, since the conventional morphology and immunophenotyping methods are limited.Conclusion:Hematopoietic cell tumors of ambiguous lineage are derived from hematopoietic stem cells with a potential of multi-differentiation. The differentiation of tumor cells is variable. We need to integrate cell morphology, flow cytometry, pathology, clinical data, and molecular genetics to make a comprehensive diagnosis.

Objective:To investigate the clinicopathological characteristics, diagnosis and differential diagnosis of liposarcoma of the extremities.Methods:Fourteen patients with atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL), dedifferentiated liposarcoma (DDL) and myxoid liposarcoma (ML) in Beijing Tiantan Hospital of Capital Medical University from March 2002 to December 2019 were collected. Fluorescence in situ hybridization (FISH) and immunohistochemical staining were used to detect the MDM2 gene amplification and expressions of S-100, CDK4 and MDM2 proteins in tumor tissues. The characteristics of different types of liposarcoma were comprehensively analyzed combined with clinical data and histopathological characteristics.Results:The age of 14 patients was (55.6±16.7) years old, with 10 males and 4 females. There were 2 cases of ALT/WDL, 6 cases of DDL, and 6 cases of ML. Immunohistochemistry showed that S-100 was positive in all patients and the patterns were scattered, partial and extensive. CDK4 and MDM2 were positive in both ALT/WDL and DDL, and weakly expressed in ML (4 cases). Vimentin was positive in all patients. MDM2 gene amplification was detected in 2 cases of ALT/WDL and 6 cases of DDL.Conclusion:Liposarcoma has a high incidence and obvious morphological diversity, accurate diagnosis is critical to the prognosis and treatment of the tumor.

Objective: To analyze the clinicopathological features of the posttransplant lymphoproliferative disorders (PTLD) and to improve the diagnostic levels. Methods: The clinical data of 11 patients diagnosed with PTLD between January 2008 and January 2018 from Henan Provincial People's Hospital, Peking University Science Center and the Affiliated Third Hospital of Peking University were collected. The clinicopathological features and the potential prognostic predictors were retrospectively analyzed by using immunohistochemical staining, EB virus in situ hybridization, fluorescence in situ hybridization and gene sequencing. Results: There were 9 males and 2 females in 11 PTLD patients, and the median age of the total patients was 18 years old (3-34 years old). The median time of 9 cases who underwent hematopoietic stem cell transplantation developing PTLD was 4 months (2-24 months) after the transplantation. The other 2 cases undergoing solid organ transplantation (SOT) occurred PTLD after 6 months and 13 months, respectively. The lymph node was the most common site to be involved (9 cases), 1 case occurred in liver and 1 case occurred in nasopharynx site. Among 11 patients, 3 cases were classified as polymorphic PTLD (P-PTLD) and the other 8 cases were monomorphic PTLD (M-PTLD). EB virus of all cases was positive, and 8 cases of M-PTLD were classified as diffuse large B-cell lymphoma (DLBCL). Fluorescence in situ hybridization was used to detect bcl-2, myc, IGH and A20 gene, and only one case had the gene break of IGH, while other cases didn't find any other abnormalities. Ig gene clone analysis was made in 5 patients with PTLD, including 4 cases of M-PTLD with gene rearrangement and 1 case of P-PTLD without gene rearrangement. Univariate analysis showed that age (≤18 years old) was associated with poor prognosis (P = 0.040). Conclusions The clinicopathologic features of PTLD are various and infected by EB virus. Gene rearrangement can help the diagnosis.