Purpose To investigate the clinicopathological features and molecular genetic alteration of Epstein-Barr virus-positive diffuse large B-cell lymphoma(EBV+DLBCL)in pediatric patients.Methods Clinical data were collected for 3 pediatric patients diagnosed with EBV+DLBCL.Immunohistochemistry(EnVision two-step method)was used to evaluate expression of CD20,CD79α,CD3,CD5,CD30,EBNA2,Fascin,and GATA3.In situ hybridization detected EBER1/2 expression.B-cell receptor(BCR)and T-cell receptor(TCR)gene rearrangements were performed to evaluate the clonal rearrangement of tumor lymphocytes.Results Among the 3 pediatric patients(ages 13-18),there were 2 males and 1 female.All patients presented with painless lymphadenopathy without bone marrow involve-ment.One female patient exhibited B symptoms(fever,night sweats,and weight loss),whereas both male patients were asymptomatic.According to the Lugano classification,2 cases were stage Ⅲand one was stage Ⅳ.Histopathologi-cally,2 cases exhibited a polymorphic morphology resembling T-cell/histiocyte-rich large B-cell lymphoma,and one case demonstrated monomorphic morphology typical of conventional DLBCL.Immunophenotypically,all cases strongly expressed various B-cell transcription factors;CD30 expression varied in intensity;EBNA2,Fascin and GATA3 were uniformly negative.In situ hybridization indicated EBER1/2 positive expression in large tumor cells and scattered back-ground small lymphocytes.Clonal Ig gene rearrangement peaks were detected in all 3 cases.Each patient received standard DLBCL chemotherapy,and follow-up PET-CT scans indicated complete remission in all.Conclusion Pediat-ric EBV+DLBCL is rare,and diagnosing the polymorphic subtype poses particular challenges.In China,many patholo-gists consider detection of clonal Ig gene rearrangement as the diagnostic"gold standard".Even when clinical course and imaging data strongly support EBV+DLBCL,final diagnosis can remain controversial.Further accumulation of ca-ses and long-term follow-up are needed to elucidate optimal diagnostic criteria,treatment responses,and prognostic fac-tors.

Purpose To investigate the clinicopathological features and molecular genetic alteration of Epstein-Barr virus-positive diffuse large B-cell lymphoma(EBV+DLBCL)in pediatric patients.Methods Clinical data were collected for 3 pediatric patients diagnosed with EBV+DLBCL.Immunohistochemistry(EnVision two-step method)was used to evaluate expression of CD20,CD79α,CD3,CD5,CD30,EBNA2,Fascin,and GATA3.In situ hybridization detected EBER1/2 expression.B-cell receptor(BCR)and T-cell receptor(TCR)gene rearrangements were performed to evaluate the clonal rearrangement of tumor lymphocytes.Results Among the 3 pediatric patients(ages 13-18),there were 2 males and 1 female.All patients presented with painless lymphadenopathy without bone marrow involve-ment.One female patient exhibited B symptoms(fever,night sweats,and weight loss),whereas both male patients were asymptomatic.According to the Lugano classification,2 cases were stage Ⅲand one was stage Ⅳ.Histopathologi-cally,2 cases exhibited a polymorphic morphology resembling T-cell/histiocyte-rich large B-cell lymphoma,and one case demonstrated monomorphic morphology typical of conventional DLBCL.Immunophenotypically,all cases strongly expressed various B-cell transcription factors;CD30 expression varied in intensity;EBNA2,Fascin and GATA3 were uniformly negative.In situ hybridization indicated EBER1/2 positive expression in large tumor cells and scattered back-ground small lymphocytes.Clonal Ig gene rearrangement peaks were detected in all 3 cases.Each patient received standard DLBCL chemotherapy,and follow-up PET-CT scans indicated complete remission in all.Conclusion Pediat-ric EBV+DLBCL is rare,and diagnosing the polymorphic subtype poses particular challenges.In China,many patholo-gists consider detection of clonal Ig gene rearrangement as the diagnostic"gold standard".Even when clinical course and imaging data strongly support EBV+DLBCL,final diagnosis can remain controversial.Further accumulation of ca-ses and long-term follow-up are needed to elucidate optimal diagnostic criteria,treatment responses,and prognostic fac-tors.

Objective To explore the clinicopathological and immunohistochemical features of wolffian adnexal tumour ( WAT) . Meth-ods The clinical and pathological features analysis and immunohistochemistry methods were utilized to study the histopathology features of a case Wolffian adnexal tumor. Results One case of unilateral WAT which located in broad ligament display a solid-cystic mass with pedicled and enveloped,its histology showed large and small tubulars,screen structure and solid zone. Its immunohistochemistry staining was positive for pan-cytokeratin,vimentin,CK18 and CD99,positive staining for α-inhibin in a little tumor cell,and negative for calretinin,CD10,EMA, ER,PR,Syn,CA15-3,CA19-9,Ki-67 index is less than 5%. PAS positive staining for the basement membrane around Gland like structure. Conclusion Wolffian adnexal tumour is diagnosised by its histopathological,immunohistochemical and it’ s distinctive location where Wolffi-an duct remnants are found.