Neuropathology最新文献

{"title":"Pediatric Spinal Cord Astrocytoma With Granular Cell-Like Morphology and KIAA1549::BRAF Fusion.","authors":"Yuka Ogawa, Takeshi Hiu, Hiroko Hayashi, Kenta Masui, Eri Shiozaki, Genki Chikamatsu, Ayaka Matsuo, Kazuaki Okamura, Shota Yoshimura, Shiro Baba, Kenta Ujifuku, Yoichi Morofuji, Koichi Yoshida, Keishi Tsunoda, Tsuyoshi Izumo, Masahiro Nakashima, Takayuki Matsuo","doi":"10.1111/neup.70081","DOIUrl":"10.1111/neup.70081","url":null,"abstract":"<p><p>We report a pediatric spinal cord tumor with prominent granular cell-like features that posed a significant diagnostic challenge. Intraoperative findings and the initial histopathological evaluation revealed marked granular cell proliferation, leading to a provisional diagnosis of granular cell astrocytoma. Notably, the classical histological features of pilocytic astrocytoma (PA) were not evident. However, molecular profiling identified a KIAA1549::BRAF fusion, prompting diagnostic reconsideration. Re-evaluation of the histopathological findings in conjunction with the molecular results supported an integrated diagnosis consistent with PA. This case highlights the marked morphological variability of PA and demonstrates that pediatric spinal circumscribed astrocytic gliomas with granular cell-like morphology may closely mimic granular cell tumors or granular cell astrocytomas. Our findings underscore the important complementary role of molecular genetic analyses, particularly the assessment of BRAF alterations, in supporting diagnosis and guiding appropriate therapeutic decision-making in diagnostically challenging pediatric spinal cord tumors.</p>","PeriodicalId":19204,"journal":{"name":"Neuropathology","volume":"46 5","pages":"e70081"},"PeriodicalIF":1.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149112807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Loss of Heterozygosity and Microsatellite Instability in Diffuse Astrocytic Gliomas: Retrospective Reinterpretation of PCR-Based Molecular Data From a Pre-IDH-Era Korean Cohort.","authors":"Na Rae Kim, Kwan Ho Park, Mi Jung Kwon, Gwangil Kim, Seong Jin Cho","doi":"10.1111/neup.70082","DOIUrl":"https://doi.org/10.1111/neup.70082","url":null,"abstract":"<p><p>The 2021 WHO Classification of Tumors of the Central Nervous System incorporates integrated molecular diagnostics into the classification of diffuse gliomas; however, access to comprehensive molecular testing remains limited in some settings. This study retrospectively evaluated grade-associated patterns of PCR-based loss of heterozygosity (LOH) and microsatellite instability (MSI) in a historical, morphology-defined cohort of diffuse astrocytic gliomas from the pre-IDH era. LOH and MSI analyses were performed using 14 LOH and 5 MSI microsatellite markers in 40 archival diffuse astrocytic gliomas, including 12 diffuse astrocytomas, NOS (WHO grade 2), 15 anaplastic astrocytomas, NOS (WHO grade 3), and 13 glioblastomas, NOS (WHO grade 4), collected between 1997 and 2002 prior to the availability of IDH immunohistochemistry. LOH-high (LOH-H) was defined as LOH involving three or more of the seven microsatellite markers examined at each locus, and MSI-high (MSI-H) as instability at two or more of the five markers. LOH was detected in 77.5% of tumors. LOH-H at 10q23 (PTEN) correlated significantly with WHO grade (8.3%, 40.0%, and 61.5% in grades 2, 3, and 4, respectively; p = 0.022) and distinguished high-grade from low-grade tumors (p = 0.015). LOH-H at either 10q23 or 17p13 (TP53) was observed in 67.9% of high-grade tumors compared with 25.0% of grade 2 tumors (p = 0.013). MSI and MSI-H rates were 17.5% and 10.0%, respectively. Three of the four MSI-H tumors lacked concurrent LOH-H; given the small number of MSI-H tumors, this observation is preliminary and should not be interpreted as evidence of distinct genomic instability pathways. LOH-H at 10q23, alone or in combination with 17p13, was associated with higher morphology-based WHO grade, whereas 17p13 LOH alone showed no significant grade association. Because IDH mutation status could not be determined, these findings should not be extrapolated to contemporary WHO-defined astrocytic gliomas; whether these findings apply to molecularly defined gliomas would require validation.</p>","PeriodicalId":19204,"journal":{"name":"Neuropathology","volume":"46 5","pages":"e70082"},"PeriodicalIF":1.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149220245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pediatric Large Cell/Anaplastic Medulloblastomas: Diagnostic Concordance and Multi-Classifier DNA Methylation Profiling, Including the In-House MAGIBU Framework.","authors":"Laura Giunti, Gianluca Mattei, Chiara Caporalini, Mirko Scagnet, Federico Mussa, Rina Agushi, Milena Guidi, Debora Vergani, Daniela Balasco, Vincenzo Yuto Civale, Chiara Carnevali, Lorenzo Genitori, Alberto Magi, Iacopo Sardi, Anna Maria Buccoliero","doi":"10.1111/neup.70080","DOIUrl":"10.1111/neup.70080","url":null,"abstract":"<p><p>Large cell/anaplastic medulloblastoma is a high-risk variant whose histopathological diagnosis can be challenging. We analyzed 12 pediatric cases enriched for LC/A morphology, with centralized review available for 11. In this deliberately selected, diagnostically challenging series, institutional and central LC/A versus non-LC/A assessments were discordant in 36% (4 of 11), illustrating the difficulty of applying the LC/A designation rather than a general estimate of inter-observer reproducibility. DNA methylation profiling was performed using four classifiers: Heidelberg CNS Tumor Methylation Classifier, Methylscape Analysis, EpiDiP, and the MAGIBU classifier, which applies a UMAP-based distance approach. Tumor classification was largely concordant across platforms, identifying two WNT-activated medulloblastomas, eight non-WNT/non-SHH medulloblastomas, and one tumor reclassified as an embryonal tumor with multilayered rosettes. One misclassification occurred with EpiDiP, where an SHH-activated medulloblastoma aligned with the normal cerebellar cortex reference profile. Copy number analysis revealed MYC amplification in two non-WNT/non-SHH tumors, chromosome 6 loss in both WNT-activated cases, and isochromosome 17q in one MYC-amplified non-WNT/non-SHH tumor. Adjunctive molecular data for a subset of cases were obtained from PedcBioPortal. The reclassified tumor lacked canonical molecular alterations but harbored additional CTNNB1 and TP53 variants whose contribution to its pathogenesis remains uncertain. One WNT-activated medulloblastoma also carried a CTNNB1 variant. The MAGIBU classifier correctly identified the ETMR case, classified all remaining tumors as medulloblastomas, and showed concordant subgroup assignment with the Heidelberg CNS Tumor Methylation Classifier and Methylscape Analysis, including the SHH-activated case misclassified by EpiDiP. On external validation across four independent medulloblastoma cohorts (n = 1063), MAGIBU achieved 98.5% family-level recall and 96.4% subclass-level recall. In conclusion, our findings indicate that, in these diagnostically challenging, LC/A-enriched cases, morphology-based diagnostic assessment can be inconsistent. DNA methylation profiling serves to refine tumor reclassification and ensure accurate risk stratification. Interpreting each tumor across complementary classifiers provides a triangulation that enhances diagnostic robustness.</p>","PeriodicalId":19204,"journal":{"name":"Neuropathology","volume":"46 5","pages":"e70080"},"PeriodicalIF":1.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149168132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metachronous Pineal Germinoma 11 Years After Total Resection of a Mature Teratoma.","authors":"Shunsuke Koga, Ilya M Nasrallah, Rachel Blue, Juan Pablo Ospina, Steven Brem, Jason Shpilsky, MacLean Nasrallah, Zissimos Mourelatos","doi":"10.1111/neup.70073","DOIUrl":"10.1111/neup.70073","url":null,"abstract":"<p><p>Central nervous system germ cell tumors are uncommon and include germinomas, teratomas, and other nongerminomatous germ cell tumors. Mature teratomas are usually cured by complete resection, but rare patients later develop a histologically distinct malignant germ cell tumor. We report a man who presented at age 20 years with a cystic pineal lesion. Gross-total resection at age 21 years showed a mature teratoma with bronchogenic differentiation and no overt immature or malignant component on H&E. Serial postoperative MRI for 3 years showed no recurrence. Eleven years after surgery, he developed headache, gait disturbance, and confusion due to a 4.6-cm pineal mass with obstructive hydrocephalus. Serum alpha-fetoprotein was normal, whereas beta-human chorionic gonadotropin (β-hCG) was elevated. The resected tumor showed sheets of large round cells with clear cytoplasm and dense lymphocytes. Immunohistochemistry demonstrated strong nuclear OCT4 and SALL4 and membranous c-KIT, with focal β-hCG-positive syncytiotrophoblastic giant cells. No nongerminomatous germ cell tumor component was identified, supporting a diagnosis of germinoma with focal syncytiotrophoblastic giant cells. After this diagnosis, retrospective evaluation of the initial tumor showed multifocal, patchy OCT4 immunoreactivity in scattered cells along the ciliated respiratory-type epithelial lining. SALL4, c-KIT, and PLAP were focally positive in corresponding regions. These findings raised the possibility of an occult germ cell marker-positive population, although no discrete expansile germinoma component was identified. This case illustrates that metachronous germinoma can develop after a long disease-free interval following resection of a mature teratoma and highlights the value of retrospective pathologic evaluation and long-term surveillance.</p>","PeriodicalId":19204,"journal":{"name":"Neuropathology","volume":"46 4","pages":"e70073"},"PeriodicalIF":1.3,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13451555/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148689443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 13-Year Review of Non-Diffuse Large B Cell Lymphomas of the Central Nervous System at a Tertiary Hospital: A Case Series Study.","authors":"Niloofar Sina, Chris Heyn, Zeina Ghorab, Julia Keith","doi":"10.1111/neup.70072","DOIUrl":"10.1111/neup.70072","url":null,"abstract":"<p><p>Non-diffuse large B-cell lymphomas (non-DLBCL) of the central nervous system (CNS) are rare and diagnostically challenging. This study aims to characterize the clinical, radiological, and pathological features of non-DLBCL CNS lymphomas diagnosed at a tertiary care center over 13 years, highlighting diagnostic pitfalls. A retrospective review was conducted of non-DLBCL CNS lymphoma cases diagnosed at Sunnybrook Health Sciences Centre, Toronto, from 2010 to 2022. Clinical, demographic, and radiological data were extracted from medical records. Imaging was reviewed by a neuroradiologist, and histopathological slides and molecular data were re-evaluated by a pathology team. Additional tests were performed to update classifications per the 5th edition of the WHO Classification of Haematolymphoid Tumors. Seventeen cases were identified (11 males, 6 females; age 38-76), compared to 72 DLBCL cases during the same period. Nine cases were extra-axial and eight intra-axial. Eight were primary and nine secondary CNS lymphomas. B-cell lymphomas (n = 13) included extra-nodal marginal zone lymphoma (n = 6), follicular lymphoma, mantle cell lymphoma, CLL, intravascular large B-cell lymphoma (n = 2), EBV+ LBCL, and polymorphic PTLD. T-cell lymphomas (n = 4) included PTCL, NOS (n = 2), ALK-negative ALCL, and secondary mycosis fungoides. Imaging revealed four major patterns, and symptoms were largely due to mass effect. This case series emphasizes the considerable heterogeneity of non-DLBCL CNS lymphomas and the diagnostic challenges they present. It highlights key features that can aid recognition and improve diagnostic accuracy for these rare CNS entities. Trial Registration: SUN-5771.</p>","PeriodicalId":19204,"journal":{"name":"Neuropathology","volume":"46 4","pages":"e70072"},"PeriodicalIF":1.3,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13438105/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148674008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CD163 Dominance Within Macrophages/Microglia Reflects a Favorable Prognosis in Patients With Glioblastoma.","authors":"Mayuko Moritsubo, Takuya Furuta, Aya Hashimoto, Hidenobu Yoshitake, Tetsuya Negoto, Hideo Nakamura, Motohiro Morioka, Hiroaki Miyoshi","doi":"10.1111/neup.70071","DOIUrl":"10.1111/neup.70071","url":null,"abstract":"<p><p>Glioblastoma is the most common primary malignant central nervous system (CNS) tumor; however, its microenvironment, including tumor-associated microglia/macrophages (TAMs), is not fully understood. Although ionized calcium-binding adaptor molecule 1 (IBA-1) is expressed in various microglial phenotypes in the healthy human brain, CD163 is a marker of activated/phagocytic microglia. Tissues from 34 patients with glioblastoma were analyzed, and 17.6% of cases were CD163-dominant. CD163-dominant patients showed better overall survival than IBA-1-dominant patients (p = 0.019). CD163 dominance was identified as an independent prognostic factor for overall survival (hazard ratio [HR], 0.17; p = 0.011). Compared with the IBA-1-dominant group, CD163-dominant tumors showed more CD4-positive cell infiltration (p = 0.005), fewer ameboid TAMs (p = 0.021), and fewer non-microvascular proliferation (non-MVP) vessels (p = 0.012). No significant differences were found in patient characteristics, such as age, sex, tumor location, or extent of resection. The CD163-to-IBA-1 ratio of TAMs is a significant independent prognostic factor in glioblastoma, suggesting that the activation status of these cells and their interactions with the vascular endothelium and T cells influence tumor progression. These findings highlight TAMs as potential therapeutic targets for glioblastoma.</p>","PeriodicalId":19204,"journal":{"name":"Neuropathology","volume":"46 4","pages":"e70071"},"PeriodicalIF":1.3,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13375595/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148471835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Primary Intracranial CIC-Rearranged Sarcoma With Prior History of B-Cell ALL: A Case Report.","authors":"Rama Aburass, Sarah Al Sharie, Nisreen Amaiyri, Nasim Sarhan, Mouness Obeidat, Maysa Al-Hussaini","doi":"10.1111/neup.70070","DOIUrl":"10.1111/neup.70070","url":null,"abstract":"<p><p>CIC-rearranged sarcoma is a rare, aggressive tumor entity with a dismal outcome. We describe a patient with a history of B-cell acute lymphoblastic leukemia (B-ALL), presenting to our hospital with seizures and left-sided upper limb weakness. Brain imaging revealed a localized right frontal mass, which was surgically resected. Initial pathological analyses suggested a secondary malignant neoplasm, not otherwise specified. However, the tumor's methylome was profiled and analyzed using the DKFZ brain tumor classifier to reach a diagnosis of CIC-rearranged sarcoma, confirmed by FISH study. The patient received the ICE protocol, alongside focal radiotherapy. The patient experienced a local recurrence 14 months post-diagnosis. The brain tumor classifier significantly improved the efficiency of diagnosing this rare tumor in a pediatric patient. However, effective therapeutic regimens for CIC-rearranged sarcomas remain unavailable.</p>","PeriodicalId":19204,"journal":{"name":"Neuropathology","volume":"46 4","pages":"e70070"},"PeriodicalIF":1.3,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13371797/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148448445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Primary Gliosarcoma With Mesenchymal Differentiation Resembling Follicular Dendritic Cell Sarcoma.","authors":"Jing Zhou, Sha Zhao, Hai Li, Shudong Yang, Minhong Pan","doi":"10.1111/neup.70060","DOIUrl":"10.1111/neup.70060","url":null,"abstract":"<p><p>Gliosarcoma of the central nervous system (CNS) is a rare and aggressive neoplasm exhibiting biphasic differentiation into glial and mesenchymal components. We report a primary gliosarcoma with mesenchymal differentiation resembling follicular dendritic cell sarcoma (FDCS). A 72-year-old man presented with a rim-enhancing lesion in the left frontotemporal parenchyma. Histologically, the tumor was biphasic, comprising a glioblastoma (GBM) component of diffusely infiltrative GFAP- and Olig2-positive oligodendroglial-like cells with microvascular proliferation, and an FDCS component composed of cohesive sheets, nests, and fascicles of CD21-, CD23-, and CD35-positive plump spindle cells. NGS analysis performed on the microdissected components revealed shared PTEN p.N48S mutations with high variant allele frequencies and MGMT promoter methylation, suggesting a monoclonal origin. Furthermore, the two components exhibited divergent genetic profiles: the glial component was characterized by an FGFR1 mutation, PDGFRA fusion, KIT/KDR amplification, and a whole-arm 1p/19q codeletion, whereas the sarcomatous component harbored an ERBB4 p.S853F mutation. These alterations predominantly converged on the RAS-MAPK and PI3K-AKT-mTOR signaling pathways. No IDH1/2 mutations, EGFR gene amplification, or TERT promoter mutations were detected in either component. This case represents the first documented instance of primary gliosarcoma with FDCS differentiation, thereby expanding its known differentiation spectrum. Furthermore, it demonstrates the necessity of separately analyzing each histological component in the diagnosis of challenging cases.</p>","PeriodicalId":19204,"journal":{"name":"Neuropathology","volume":"46 3","pages":"e70060"},"PeriodicalIF":1.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147856430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The First Autopsy-Proven Case of CSF1R-Related Leukoencephalopathy Harboring the p.Cys774Arg Mutation.","authors":"Hiroyuki Hatsuta, Akitoshi Takeda, Tomomi Fujita, Yuji Nakayama, Kaoru Yagita, Terunori Sano, Taro Shimono, Kaori Sakamoto, Kenichi Kohashi, Ai Obinata, Toshiya Kizaki, Norikazu Hara, Akinori Miyashita, Takeshi Ikeuchi, Yoshiaki Itoh, Masaki Takao","doi":"10.1111/neup.70065","DOIUrl":"10.1111/neup.70065","url":null,"abstract":"<p><p>We report the first autopsy-proven case of colony-stimulating factor 1 receptor (CSF1R)-related leukoencephalopathy harboring the CSF1R mutation c.2320T>C (p.Cys774Arg). The patient, a man in his 40s, exhibited progressive neuropsychiatric symptoms with predominant frontal white matter lesions and corpus callosum atrophy. Neuropathological examination revealed frontal-predominant demyelination with a relatively low number of axonal spheroids compared with typical cases, as well as the absence of intracranial calcifications. In addition, prominent cerebral amyloid angiopathy was observed despite an APOE ε3/ε3 genotype. These findings expand the clinicopathological spectrum of CSF1R-related leukoencephalopathy and highlight variability in pathological features associated with different CSF1R mutations.</p>","PeriodicalId":19204,"journal":{"name":"Neuropathology","volume":"46 3","pages":"e70065"},"PeriodicalIF":1.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148205841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lymphoplasmacyte-Rich Meningioma: Possible Formation of Intratumoral \"Tertiary Lymphoid Structures\".","authors":"Masayuki Shintaku, Takahiro Hamamoto, Tetsuo Hashiba, Masahiro Nonaka, Takeo Nakaya, Katsunori Uchida, Koji Tsuta","doi":"10.1111/neup.70059","DOIUrl":"10.1111/neup.70059","url":null,"abstract":"<p><p>A surgical case of lymphoplasmacyte-rich (LPR) meningioma that arose in the region of the clivus of an 81-year-old woman is reported. The tumor consisted largely of a dense and diffuse infiltration of mature lymphocytes and a smaller number of plasma cells. Mainly in the peripheral region of the tumor, small sheets or clusters of large polygonal cells having vesicular nuclei and palely eosinophilic cytoplasm were observed. Some of these cells formed cellular whorls. These cells showed immunoreactivity for progesterone receptor, epithelial membrane antigen, somatostatin receptor type 2A, epithelial cadherin, and podoplanin, thus confirming the diagnosis of LPR meningioma. Although lymph follicles having germinal centers were not evident, the distributions of lymphocytes and plasma cells were heterogeneous, and plasma cells occasionally appeared to surround lymphocytic aggregates. Some intratumoral venules showed features of \"high endothelial venules.\" These findings suggested that a dense accumulation of lymphocytes and plasma cells in LPR meningioma was not a simple inflammatory cell infiltration but might represent formation of \"tertiary lymphoid structures.\" Whereas some inflammatory cells showed cytoplasmic immunoreactivity for programmed cell death ligand-1, meningioma cells did not express it.</p>","PeriodicalId":19204,"journal":{"name":"Neuropathology","volume":"46 3","pages":"e70059"},"PeriodicalIF":1.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147840350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}