Purpose This study aims to investigate the clinicopathological features of diffuse pulmonary menin-gotheliomatosis(DPM).Methods The clinical data of 10 patients with DPM undergoing video-assisted thoracic sur-gery(VATS)were collected,and their clinical and pathological characteristics were analyzed using immunohistochem-istry.Results The detection rate of DPM was 1.19‰,with 90％of the patients being female.DPM predominantly occurred in the age range of 40-60 years,with an average age at diagnosis of 50.7 years.Most patients had no smok-ing history.Pathological diagnosis combined with imaging findings was the main method for diagnosing DPM.80％of the patients were prone to concurrent early-stage invasive pulmonary adenocarcinoma.Laboratory indicators,including pulmonary function,were generally normal.Chest CT showed diffuse multiple ground-glass opacity or cystic nodules in both lungs,with the number of nodules in both lungs ranging from dozens to hundreds,and the maximum diameter of the nodules was 2-6 mm.The median volume and CT value of the pulmonary nodules were 35.32 mm3 and-566 HU,respectively.Pathological features mainly included multiple meningothelial-like nodules observed under the micro-scope.Immunophenotypically,CD56,EMA,PR,and vimentin were often positive.Conclusion DPM is a rare lung disease with no obvious clinical symptoms,and is more common in middle-aged and elderly women.Diffuse multiple nodules in both lungs are its main imaging features.Most DPM patients are complicated with lung adenocarcinoma,and regular follow-up is recommended.

Purpose To explore the clinical and pathological characteristics,diagnostic features,differential diag-nosis,and prognosis of polymorphous low-grade neuroepithelial tumor of the young(PLNTY).Methods Clinical and imaging data from 7 patients with PLNTY were collected.Morphological evaluation was performed using HE staining.Immunohistochemistry with the EnVision method was used to detect the expression of including CD34,BRAF,IDH1,GFAP,Ki67,and other proteins.BRAF gene mutations were detected by real-time PCR,CDKN2A/B and 1p/19q co-deletion were assessed by FISH,and next-generation sequencing(NGS)was performed on selected cases.Results Among the seven patients,six were male and one was female,aged 8-29 years(median age:22 years).Tumors were located in the temporal lobe(5 cases),left insula and anterior temporal lobe(1 case),and frontotemporal lobe(1 case).Six patients had a history of epilepsy.Histologically,all tumors displayed oligodendroglioma-like areas.Two cases exhibited perivascular pseudorosette-like arrangements,and two showed focal cellular pleomorphism.Calcifica-tion and capillary networks were observed in all cases.Immunohistochemically,all tumors were positive for GFAP and Olig-2 and negative for IDH1(R132H).CD34 showed diffuse positivity in all cases.BRAF was positive in five cases.The Ki67 proliferation index ranged from 1％to 5％.Molecularly,all cases were IDH-wild type,with no 1p/19q co-deletion or CDKN2A/B deletion.BRAF V600E mutants were identified in five cases,and FGFR alterations in two.During follow-up(5-48 months),all patients survived;five remained recurrence-free,while two experienced recur-rence.Conclusion As a rare low-grade neuroepithelial tumor,clinicians and pathologists should master the diagnostic key points and differential diagnosis of PLNTY to avoid misdiagnosis and missed diagnosis.

Purpose To explore the clinical manifestations,imaging features,and histopathological characteristics of intravascular large B-cell lymphoma(IVL-BCL)involving the central nervous system(CNS).Methods Clinical and imaging data from 5 cases of IVL-BCL were collected.Immunohistochemical staining and FISH were performed to analyze their clinicopathological characteristics,with a comprehensive review of relevant literatures.Results All 5 pa-tients were elderly,with a male-to-female ratio of 4∶1,and an age of onset ranging from 53 to 67 years.The disease course varied from 4 months to 2 years.All patients had varying degrees of neurological damage symptoms.In this study,4 patients experienced varying degrees of weakness in the lower limbs.MRI findings were nonspecific,but all 5 patients showed evidence of cerebrovascular lesions.Histologically,the lesions were characterized by aggregates of lymphoid tumor cells within the lumens of small cerebral vessels,which could obstruct the lumens and cause ischemic and hypoxic changes.Tumor cells did not involve the extravascular brain parenchyma.Immunohistochemically,tumor cells widely expressed mature B-cell markers(CD19,CD20,CD79a,PAX5)with a high Ki67 proliferation index.All 5 patients received systemic chemotherapy after diagnosis,1 patient died,2 patients achieved clinical and physical symptom relief and were still under follow-up.2 patients were undergoing systemic examination before chemotherapy.Conclusion Intravascular large B-cell lymphoma involving the central nervous system is rare,and both clinical mani-festations and imaging examinations lack specific indicators.Preoperative diagnosis is very difficult and can only rely on diagnostic brain biopsy or pathological diagnosis after craniotomy.

Purpose To investigate the expression and clinical significance of the embryonic lethal abnormal vi-sion-like(ELAVL)family in glioma.Methods Pan-cancer and glioma-specific analyses of mRNA expression profiles of the ELAVL family were analyzed using the TCGA and GTEx databases.The association between ELAVL family ex-pression and survival of glioma patients was evaluated via the gene expression profiling interactive analysis 2(GEPIA2)database.The expression level of ELAVL2 protein in human glioma tissues and non-tumor control brain tissues was ver-ified by immunohistochemistry,and the relationship between its expression and prognosis was analyzed based on the fol-low-up data of patients.Western blot was performed to assess ELAVL2 protein levels in human immortalized astrocytes of UC2 and seven glioma cell lines.Overexpression of ELAVL2 in glioma cells was achieved to evaluate its impact on cell proliferation using in vitro assays.Results Compared to normal tissues,the ELAVL family exhibited distinct ex-pression patterns across various cancers.In glioma,ELAVL1 was significantly upregulated,while ELAVL2,ELAVL3 and ELAVL4 were markedly downregulated.Survival analysis revealed that low ELAVL2 expression was an independent prognostic factor for poor survival in glioma patients(P＜0.05).Immunohistochemistry confirmed that the expression of ELAVL2 decreased with the increase of glioma grade,and its low expression indicated a poor prognosis for patients(P＜0.001).Overexpression of ELAVL2 inhibited glioma cell proliferation in vitro(P＜0.001),suggesting its tumor-suppressive role.Conclusion The ELAVL family members play a critical role in glioma progression.ELAVL2 downregulation serves as a marker for adverse clinical outcomes and represents a potential therapeutic target for glioma therapy.

Tumor-associated neutrophils(TANs)play a pivotal role in the immunotherapy of colorectal cancer(CRC).Within the tumor microenvironment,TANs display intricate functions,embodying both tumor-facilitating and tumor-inhibiting characteristics.TANs can be categorized into N1 type(with tumor-suppressive capabilities)and N2 type(exhibiting tumor-promoting tendencies),both of which are intimately linked to tumor progression and patient prognosis.Indicators such as the neutrophil/lymphocyte ratio(NLR)and neutrophil extracellular traps(NETs)are correlated with the prognosis of CRC.Potential targets for TANs-related immunotherapy encompass modulating their po-larization state and impeding immunosuppressive functions.The combined utilization with other immunotherapeutic mo-dalities holds the promise of augmenting the therapeutic efficacy.Notwithstanding the numerous challenges,in-depth exploration of the mechanisms underlying TANs and optimization of the treatment strategies pave novel pathways for CRC treatment in the future.

Purpose To investigate the clinical pathological features and treatment strategies of adult pineoblasto-ma(PB).Methods The clinical data of 11 cases of adult PB were retrospectively analyzed.Their imaging,histologi-cal morphology,and immunohistochemical characteristics were evaluated,and the relevant literature was reviewed.Re-sults Among the 11 PB cases,5 cases were female and 6 were male,aged 18-63 years with a median age of 39 years.Microscopically,the tumors were composed of dense small to medium-sized cells,showing a diffuse and sheet-like distribution.Rosette-like structures could be seen in some cases.The tumor cell nuclei were round or irregular with a high nuclear-cytoplasmic ratio.The mitotic figures and apoptosis were extremely common to see,and necrosis was observed in some cases.The tumor cells were uniformly positive for CD56(11/11),Syn(11/11),and CgA(11/11),with retained expression of INI-1(11/11).Some cases were positive for CD99(3/11)and S-100(1/11),while negative for BCOR,CKpan,GFAP,PLAP,CD3,and CD20.The Ki67 proliferation index ranged from 20％to 80％.Five patients were followed up for 2 to 39 months:1 patient developed spinal metastasis 26 months after postop-erative chemotherapy;1 patient had spinal metastasis 4 months after postoperative radiotherapy and temozolomide treat-ment;and 3 patients died.Conclusion PB is a rare,highly malignant tumor in the pineal gland region,even rarer in adults.Its morphology is similar to that of childhood PB,and its prognosis is slightly better than that in children.

Purpose To investigate the clinicopathological features,diagnostic approaches,and differential diag-nosis of chordoid glioma(CG)and chordoid meningioma(CM)of the central nervous system(CNS).Methods Clinical data from 4 cases of CG and 10 cases of CM were collected.Immunohistochemistry was used to detect the ex-pression of GFAP,EMA,TTF-1,and other markers.Molecular genetic alerations were identified using sequencing techniques and relevant literature was reviewed.Results CG predominantly occurred in the third ventricle but could also arise outside of it.Tumors showed well-defined borders with surrounding tissues.Microscopically,tumor cells were arranged in cords or clusters within a myxoid stroma and expressed GFAP,TTF-1,and other markers.No PRKCA(D463H)mutations were detected in 3 CG cases,however,one case harbored an FLCN ∷ PRKD2 fusion.CM predom-inantly occurred in the supratentorial region but also appeared in the subtentorial area.Histologically,chordoid compo-nents were mixed with classic meningioma features.Chronic inflammatory cell infiltration was noted in the stroma.Tumor cells expressed EMA,PR and SSTR2.One case harbored NF2 mutation and homozygous CDKN2A deletion.Conclusion CG and CM of the CNS shared overlapping morphological characteristics,making histological distinction difficult.Accurate diagnosis required integration of clinical,imaging,immunohistochemical,and molecular pathologi-cal findings.

Hereditary tumor predisposition syndromes of the central nervous system(CNS)are a group of genetic disorders caused by germline mutations,which significantly increase the risk of CNS tumors in carriers.However,awareness of these syndromes remains limited in current clinical and pathological practice,leading to a high risk of un-derdiagnosis and missdiagnosis.Pathologists should integrate clinical history,family history,tumor morphology,and molecular testing results to identify underlying hereditary tumor predisposition syndromes.This approach not only helps assess multi-organ tumor risks and guide personalized treatment but also enables early intervention through genetic counseling and testing for family members,ultimately improving patient outcomes and aiding in disease prevention and reproductive decision-making.

Purpose To explore the key molecules mechanisms underlying the selective activation of macrophage and the regulation of Dicer expression induced by glioblastoma(GBM)cells,as well as its prognostic significance.Methods Glioblastoma conditional medium(GCM)was fractionated by molecular weight using ultrafiltration.Specif-ic molecular weight components of GCM that upregulate Dicer expression in mouse bone marrow derived macrophages(BMDMs)were identified.Secreted proteins were identified by mass spectrometry(MS).The correlation between candidate proteins and GBM prognosis was analyzed using the TCGA and CGGA database.In vitro experiments of the candidate proteins on Dicer expression in BMDMs were further carried out.Results GCM components with a molecu-lar weight of＞50 kDa significantly upregulated Dicer expression in BMDMs.MS identified five key secreted proteins:Prg4,Psap,Hexa,Aebp1,and Itih2.High expression of Prg4 was significantly positively correlated with poor progno-sis in GBM patients(P＜0.001)and was associated with the expression of selective macrophage activation markers.Recombinant Prg4 protein stimulated BMDMs and induced Dicer expression in mouse BMDMs.Conclusion This study reveals that glioma cells induce Dicer expression in macrophages by secreting Prg4,providing a theoretical basis for GBM therapeutic strategies targeting the Prg4-Dicer axis.

Telomerase reverse transcriptase(TERT)promoter mutation(TPM)in the TERT gene is one of the most frequent genetic alterations in adult-type diffuse gliomas,particularly in IDH-wildtype glioblastoma and IDH-mu-tant oligodendroglioma with 1p/19q co-deletion.Consequently,the WHO(2021)classification of tumors of the central nervous system incorporates TPM as a key molecular criterion for molecular subtyping and grading,differential diagno-sis,prognosis assessment,and treatment-planning in these gliomas.This article briefly reviews the physiological roles of TERT,the relationship between TPM and gliomagenesis.In order to provide reference for clinical practice.