Objective To construct an index system for assessment of schistosomiasis transmission risk following natural disasters such as rainstorms, floods, earthquakes, mudslides, and landslides, so as to provide insights into rapid identification of schistosomiasis transmission risk post-disasters and formulation of targeted schistosomiasis control strategies. Methods An initial framework for the index system for assessment of schistosomiasis transmission risk following natural disasters was drafted through literature review, brainstorming, and focus group discussions. Two rounds of expert correspondence consultations were conducted using the Delphi method to refine and finalize the system, and the degrees of expert activeness, authority and endorse ment, and consensus were evaluated. In addition, the weights of each index were calculated using the analytic hierarchy process. Results A total of 18 experts participated in the consultation. The expert positive coefficients were 100.00% and 94.44% for two rounds of consultations, with authority coefficients of 0.92 and 0.94, respectively. The coefficients of coordination on the index importance, rationality and operability were 0.209, 0.185, 0.222 and 0.407, 0.214, 0.257 for two rounds of consultations, respectively, and all consistency tests were statistically significant (χ² = 246.771 to 505.278, all P values < 0.001). Following two rounds of expert consultations, an index system consisting of 6 first-level indicators, 15 second-level indicators, and 49 third-level indicators was ultimately constructed. In terms of first-level indicators, “disaster situation”, “previous epidemics”, “healthcare guarantee”, “response capacity” and “emergency recovery” had the highest weights, each at 18.18%. Regarding second-level indicators, “Schistosoma japonicum infections in animals”, “S. japonicum infections in snails” and “medical treatment” had the highest weights, each at 7.35%. In terms of third-level indicators, ten items had the highest weights, including “identification of schistosomiasis cases”, “detection of S. japonicum infections in wild feces”, “detection of S. japonicum infections in snails”, “reserves of schistosomiasis diagnostic/testing reagents and consumables”, “reserves of chemotherapy agents for human and animal schistosomiasis”, “reserves of cercariacides”, “periodical surveillance on schistosomiasis”, “identification of schistosomiasis transmission risk and timely response”, “normal provision of diagnosis and treatment services” and “post-disaster schistosomiasis surveillance”, each at 2.40%. Conclusion A scientific, systematic, and practical index system has been constructed for assessment of schistosomiasis transmission risk following natural disasters, which may provide insights into rapid post-disaster identification of schistosomiasis transmission risk, formulation of targeted schistosomiasis control strategies and optimization of resource allocation.

Objective:This study investigated the underlying causes of discordance between multiplex fluorescence polymerase chain reaction (PCR)-capillary electrophoresis in determining MSI and immunohistochemistry (IHC) for mismatch repair (MMR) protein evaluation in gastrointestinal adenocarcinomas, aiming to improve interpretation accuracy and guide clinical precision treatment strategies.Methods:A retrospective analysis was conducted on 511 surgically resected or biopsied specimens (161 gastric adenocarcinomas and 350 colorectal adenocarcinomas) diagnosed at the Department of Pathology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January to June 2024. MMR protein expression of tumors was evaluated by IHC, while MSI status was assessed using the 2B3D National Cancer Institute (NCI) Panel through multiplex fluorescence PCR-capillary electrophoresis on tumor DNA and matched normal DNA. The concordance between the two methods was analyzed, and factors contributing to the discordance were investigated. Cases with unstable dinucleotide loci only in the 2B3D NCI Panel, focal MMR protein loss, or unexplained discrepancies underwent validation using the non-NCI Panel through multiplex fluorescence PCR-capillary electrophoresis markers or next-generation sequencing (NGS).Results:In the 511 gastrointestinal adenocarcinomas, the results of the two methods were discordant in 15 cases (2.9%), with a significantly higher discordantrate in gastric cancers (7.5%, 12/161) compared to colorectal cancers (0.9%, 3/350; P＜0.001). Key contributors to the discordance included: sampling limitations (6 cases), 2B3D NCI Panel design constraints (3 cases),tumor heterogeneity (3 cases),isolated MSH6 deficiency (1 case),and unexplained discrepancies (2 cases).Validation studies demonstrated that cases with dinucleotide-only instability showed concordance with IHC after using the non-NCI Panel through multiplex fluorescence PCR-capillary electrophoresis and NGS verifications. Specimens with focal MMR protein loss and unexplained discrepancies aligned with initial PCR results upon NGS validation. Unexplained cases harbored Kirsten rat sarcoma class Ⅰ variants and multiple class Ⅱ genetic alterations. Conclusions:Colorectal adenocarcinoma demonstrated higher concordance between PCR-capillary electrophoresis and IHC than gastric adenocarcinoma.Discordant results require systematic evaluation including technical review, specimen quality control, and supplemental NGS analysis to resolve discrepancies.

Objective:To investigate the clinicopathological and genetic characteristics of monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL).Methods:The forty-two MEITL cases diagnosed in the Department of Pathology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China from 2016 to 2022 was retrospectively analyzed. Clinical data were collected, and follow-up was performed. Morphological characteristics were observed. Immunohistochemistry, Epstein-Barr virus (EBV) in situ hybridization, clonal rearrangement analysis of T-cell receptor (TCR) genes, and targeted next-generation sequencing (NGS) were performed.Results:Among the 42 patients (male/female ratio of 2.8∶1.0), the age range was 32-77 years with a median age of 59.5 (52.0-65.0) years. Grossly, the tumors were presented as ulcerative or exophytic lesions, with a maximum diameter of 2-18 cm. There were 34 cases with a single lesion and 8 cases with more than 1 lesion. The tumor cells in all 42 cases were relatively monotonous in histology and small or medium in size. They had round or oval nuclei, moderately pale or clear cytoplasm, evenly distributed nuclear chromatin, inconspicuous nucleoli, and frequent mitotic figures. In one of the cases, there were moderately large cells, vacuolated nuclei, and clear nucleoli. Lymphoepithelial lesions were observed in 36 (85.7%) of the 42 cases, tumor necrosis in 4 (9.5%) cases, scattered eosinophils and/or plasma cell infiltration in the background in 9 (21.4%) cases, and a "starry sky" phenomenon in 1 (2.4%) case. The tumor cells in all cases exhibited high expression of CD3, CD2, CD7, CD8, CD56, TIA1, Granzyme B, and Perforin, while some also expressed CD4 (5/41, 12.2%), CD5 (3/41, 7.3%), CD20 (4/41, 11.9%), CD79α (2/37, 5.4%), and CD30 (1/34, 2.9%). The Ki-67 proliferation index ranged from 40% to 90%. EBER in situ hybridization tests were negative in all cases. TCR gene clonal rearrangement was detected in 96.4% (27/28) of the tested cases. Targeted NGS revealed commonly mutated genes including SETD2, STAT5B, JAK3, TP53, and CREBBP. The primary treatment was chemotherapy, with 2 cases undergoing autologous hematopoietic stem cell transplantation. Follow-up information was obtained for 29 cases, with a follow-up period of 1-73 months. The mortality was 93.1% (27/29).Conclusions:MEITL is a rare and highly aggressive peripheral T-cell lymphoma. Its clinical manifestations are diverse, and diagnosis primarily relies on a comprehensive assessment of pathological morphology, immunohistochemical profiles, and EBV infection status, supplemented by genetic testing if necessary. At present, there is no effective treatment, and its overall prognosis is poor.

Purpose To investigate the clinicopathological features and prognosis of adult large B-cell lymphoma with IRF4 rearrangement(LBCL-IRF4r).Methods Clinical data of 63 adult LBCL-IRF4r cases were collected.The EnVision two-step method was employed for immunohistochemical staining,and fluorescence in situ hybridization was used to detect rearrangements or deletions of the IRF4,BCL2,MYC,BCL6,and TP53 genes.The relationship be-tween clinicopathological features and prognosis was analyzed and compared with data from 132 adult non-specified dif-fuse large B-cell lymphoma(DLBCL)cases.Results Among the 63 adult LBCL-IRF4r patients,the male to female ratio was 1.1∶1,with a median age of 54.0 years(range 20-84 years),and 14 cases(22.2％)were＜40 years old,24 cases(38.1％)were between 40 and 60 years old,and 25 cases(39.7％)were＞60 years old.18 cases(28.6％)were involved in Waldeyer's ring,along with 8 cases(12.7％)in cervical lymph nodes,7 cases(11.1％)in other lymph nodes and lymphatic organs,13 cases(20.6％)in stomach,4 cases(6.4％)in intestine,and 13 cases(20.6％)in other extranodal sites.63 cases showed IRF4 rearrangements,with no BCL2 and MYC translocations(0/58),30.9％(17/55)had BCL6 translocations,and 16.3％(8/49)had TP53 deletions.59 pa-tients were followed up for a median of 28 months(range 1-65 months).48 patients(81.4％)achieved complete re-sponse,10 patients(16.9％)experienced disease progression or relapse,and 3 patients(5.1％)died.Univariate a-nalysis showed that lactate dehydrogenase level,Ann Arbor stage,international prognostic index(IPI)score,growth pattern,Hans classification,and double expression of BCL2 and C-MYC were significantly associated with progression-free survival.Age,Ann Arbor stage,and IPI score were significantly associated with overall survival.Multivariate Cox regression analysis showed that double expression of BCL2 and C-MYC was an independent prognostic factor for pro-gression-free survival.Adult LBCL-IRF4r had significantly higher complete response rate and progression-free survival than adult DLBCL.Conclusion LBCL-IRF4r occurs in adults of all age groups,commonly affecting Waldeyer's ring,cervical lymph nodes,and gastrointestinal tract,and has a favorable clinical prognosis.

The 2022 5th edition WHO Classification of Haematolymphoid Tumours introduces significant revisions to histiocytic and dendritic cell neoplasms,involving the reclassification and renaming of certain diseases alongside the addition of new distinct entities.This article systematically interprets these updates and summarizes the key points for the diagnosis and differential diagnosis of histiocytic neoplasms,aiming to enhance diagnostic accuracy and treatment outcomes for this disease group.

Purpose To investigate the clinical,imaging,and pathological features of Kikuchi-Fujimoto disease(KFD).Methods A retrospective analysis was conducted on 123 pathologically confirmed KFD cases.Clinical and imaging data were collected,and histopathological features were evaluated using HE staining,immunohistochemistry,in situ hybridization for EBER,and molecular analyses(TCR/Ig gene rearrangements by PCR with capillary electro-phoresis).Results Among the 123 patients,the male-to-female ratio was 1∶2,with a median age of 30 years.All patients presented with lymphadenopathy.Among 30 hospitalized patients,63.3％(19/30)had fever,and 23.3％(7/30)had concurrent autoimmune diseases.Of the 12 patients who underwent PET-CT,91.7％(11/12)were sus-pected of malignancy,prompting biopsy recommendations.Among 47 consultation cases,27.7％(13/47)were ini-tially misdiagnosed as lymphoma.Histopathological examination revealed proliferative,necrotic,and xanthomatous phases,which coexisted or occurred independently.The proliferative phase was characterized by atypical lymphocytes and histiocytes,the necrotic phase by abundant eosinophilic fibrin deposits and nuclear debris,and the xanthomatous phase by clusters of foam-like histiocytes.Immunohistochemically analyses revealed that atypical lymphocytes were neg-ative for CD20,CD4,and CD56 but positive for CD3,CD8,TIA1,Granzyme B,and Perforin.Histiocytes expressed CD68,CD163,and MPO,while CD123-positive plasmacytoid dendritic cells were predominantly located around the le-sions and blood vessels.EBER was positive in individual cells in 4 cases.TCR gene rearrangement was positive in 2 cases and suspected positive in 3 cases,while Ig rearrangement was positive and suspected positive in 1 case each.Conclusion KFD exhibits clinical,imaging,and pathological features that can mimic lymphoma,highlighting the im-portance of accurate diagnosis to avoid misdiagnosis and inappropriate treatment.

Purpose To investigate the clinicopathological features and prognosis of adult large B-cell lymphoma with IRF4 rearrangement(LBCL-IRF4r).Methods Clinical data of 63 adult LBCL-IRF4r cases were collected.The EnVision two-step method was employed for immunohistochemical staining,and fluorescence in situ hybridization was used to detect rearrangements or deletions of the IRF4,BCL2,MYC,BCL6,and TP53 genes.The relationship be-tween clinicopathological features and prognosis was analyzed and compared with data from 132 adult non-specified dif-fuse large B-cell lymphoma(DLBCL)cases.Results Among the 63 adult LBCL-IRF4r patients,the male to female ratio was 1.1∶1,with a median age of 54.0 years(range 20-84 years),and 14 cases(22.2％)were＜40 years old,24 cases(38.1％)were between 40 and 60 years old,and 25 cases(39.7％)were＞60 years old.18 cases(28.6％)were involved in Waldeyer's ring,along with 8 cases(12.7％)in cervical lymph nodes,7 cases(11.1％)in other lymph nodes and lymphatic organs,13 cases(20.6％)in stomach,4 cases(6.4％)in intestine,and 13 cases(20.6％)in other extranodal sites.63 cases showed IRF4 rearrangements,with no BCL2 and MYC translocations(0/58),30.9％(17/55)had BCL6 translocations,and 16.3％(8/49)had TP53 deletions.59 pa-tients were followed up for a median of 28 months(range 1-65 months).48 patients(81.4％)achieved complete re-sponse,10 patients(16.9％)experienced disease progression or relapse,and 3 patients(5.1％)died.Univariate a-nalysis showed that lactate dehydrogenase level,Ann Arbor stage,international prognostic index(IPI)score,growth pattern,Hans classification,and double expression of BCL2 and C-MYC were significantly associated with progression-free survival.Age,Ann Arbor stage,and IPI score were significantly associated with overall survival.Multivariate Cox regression analysis showed that double expression of BCL2 and C-MYC was an independent prognostic factor for pro-gression-free survival.Adult LBCL-IRF4r had significantly higher complete response rate and progression-free survival than adult DLBCL.Conclusion LBCL-IRF4r occurs in adults of all age groups,commonly affecting Waldeyer's ring,cervical lymph nodes,and gastrointestinal tract,and has a favorable clinical prognosis.

Purpose To investigate the clinical,imaging,and pathological features of Kikuchi-Fujimoto disease(KFD).Methods A retrospective analysis was conducted on 123 pathologically confirmed KFD cases.Clinical and imaging data were collected,and histopathological features were evaluated using HE staining,immunohistochemistry,in situ hybridization for EBER,and molecular analyses(TCR/Ig gene rearrangements by PCR with capillary electro-phoresis).Results Among the 123 patients,the male-to-female ratio was 1∶2,with a median age of 30 years.All patients presented with lymphadenopathy.Among 30 hospitalized patients,63.3％(19/30)had fever,and 23.3％(7/30)had concurrent autoimmune diseases.Of the 12 patients who underwent PET-CT,91.7％(11/12)were sus-pected of malignancy,prompting biopsy recommendations.Among 47 consultation cases,27.7％(13/47)were ini-tially misdiagnosed as lymphoma.Histopathological examination revealed proliferative,necrotic,and xanthomatous phases,which coexisted or occurred independently.The proliferative phase was characterized by atypical lymphocytes and histiocytes,the necrotic phase by abundant eosinophilic fibrin deposits and nuclear debris,and the xanthomatous phase by clusters of foam-like histiocytes.Immunohistochemically analyses revealed that atypical lymphocytes were neg-ative for CD20,CD4,and CD56 but positive for CD3,CD8,TIA1,Granzyme B,and Perforin.Histiocytes expressed CD68,CD163,and MPO,while CD123-positive plasmacytoid dendritic cells were predominantly located around the le-sions and blood vessels.EBER was positive in individual cells in 4 cases.TCR gene rearrangement was positive in 2 cases and suspected positive in 3 cases,while Ig rearrangement was positive and suspected positive in 1 case each.Conclusion KFD exhibits clinical,imaging,and pathological features that can mimic lymphoma,highlighting the im-portance of accurate diagnosis to avoid misdiagnosis and inappropriate treatment.

The 2022 5th edition WHO Classification of Haematolymphoid Tumours introduces significant revisions to histiocytic and dendritic cell neoplasms,involving the reclassification and renaming of certain diseases alongside the addition of new distinct entities.This article systematically interprets these updates and summarizes the key points for the diagnosis and differential diagnosis of histiocytic neoplasms,aiming to enhance diagnostic accuracy and treatment outcomes for this disease group.

Objective:To investigate the clinicopathological and genetic characteristics of monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL).Methods:The forty-two MEITL cases diagnosed in the Department of Pathology, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China from 2016 to 2022 was retrospectively analyzed. Clinical data were collected, and follow-up was performed. Morphological characteristics were observed. Immunohistochemistry, Epstein-Barr virus (EBV) in situ hybridization, clonal rearrangement analysis of T-cell receptor (TCR) genes, and targeted next-generation sequencing (NGS) were performed.Results:Among the 42 patients (male/female ratio of 2.8∶1.0), the age range was 32-77 years with a median age of 59.5 (52.0-65.0) years. Grossly, the tumors were presented as ulcerative or exophytic lesions, with a maximum diameter of 2-18 cm. There were 34 cases with a single lesion and 8 cases with more than 1 lesion. The tumor cells in all 42 cases were relatively monotonous in histology and small or medium in size. They had round or oval nuclei, moderately pale or clear cytoplasm, evenly distributed nuclear chromatin, inconspicuous nucleoli, and frequent mitotic figures. In one of the cases, there were moderately large cells, vacuolated nuclei, and clear nucleoli. Lymphoepithelial lesions were observed in 36 (85.7%) of the 42 cases, tumor necrosis in 4 (9.5%) cases, scattered eosinophils and/or plasma cell infiltration in the background in 9 (21.4%) cases, and a "starry sky" phenomenon in 1 (2.4%) case. The tumor cells in all cases exhibited high expression of CD3, CD2, CD7, CD8, CD56, TIA1, Granzyme B, and Perforin, while some also expressed CD4 (5/41, 12.2%), CD5 (3/41, 7.3%), CD20 (4/41, 11.9%), CD79α (2/37, 5.4%), and CD30 (1/34, 2.9%). The Ki-67 proliferation index ranged from 40% to 90%. EBER in situ hybridization tests were negative in all cases. TCR gene clonal rearrangement was detected in 96.4% (27/28) of the tested cases. Targeted NGS revealed commonly mutated genes including SETD2, STAT5B, JAK3, TP53, and CREBBP. The primary treatment was chemotherapy, with 2 cases undergoing autologous hematopoietic stem cell transplantation. Follow-up information was obtained for 29 cases, with a follow-up period of 1-73 months. The mortality was 93.1% (27/29).Conclusions:MEITL is a rare and highly aggressive peripheral T-cell lymphoma. Its clinical manifestations are diverse, and diagnosis primarily relies on a comprehensive assessment of pathological morphology, immunohistochemical profiles, and EBV infection status, supplemented by genetic testing if necessary. At present, there is no effective treatment, and its overall prognosis is poor.