Brain Tumor Pathology最新文献

Cerebellar liponeurocytoma (cLNC), categorized as a World Health Organization grade II tumor, is a rare neoplasm characterized by advanced neuronal/neurocytic differentiation and focal lipid accumulation in neuroepithelial tumor cells. However, the expression and genetic profiling of cLNC have been poorly studied. A 44-year-old woman with a three-year history of cerebellar ataxia and numbness in lower extremities underwent radiological examination revealing multiple contrast-enhancing tumors at the floor of the fourth ventricle and in the lower vermis, and spinal dissemination. The high uptake of 11 C-methionine in positron emission tomography (Met-PET) supported the preoperative cLNC diagnosis. Subtotal removal of the tumor around the obex and inferior vermis was performed. Histologically, the tumor was composed of small, uniform cells with round nuclei in a sheet-like fashion. Tumor cells were diffusely reactive for the neuronal markers synaptophysin and neurofilament. Vacuolate cells with a displacement of nuclei suggested the accumulation of lipid, which was further supported by immunohistochemical staining of S-100. These findings confirmed the diagnosis of cLNC. Next-generation sequencing of tumoral DNA detected a splice site mutation in the ATRX gene. Further reports of cLNC cases with detailed expression and genetic profiles are essential for precise diagnosis and clarifying the oncogenic pathway in cLNC.

As a new concept of glioma therapy, immunotherapy combined with standard therapies is a promising modality to improve glioma patient survival. VEGF and its signaling pathway molecules not only inhibit angiogenesis but also may reinforce the immunosuppressive tumor microenvironment, including promotion of the accumulation of immunosuppressive tumor-associated macrophages (TAMs). In this review, we discuss VEGF-targeted therapy as a new treatment option of the TAM-targeted therapy for high-grade gliomas, as well as other TAM-targeted therapies. The authors also discuss the potential of these therapies combined with conventional immunotherapies.

Lymphomatoid granulomatosis (LYG) is a rare lymphoproliferative disease with angiocentric and angiodestructive infiltrates, and by definition, Epstein-Barr virus (EBV)-associated B-cell malignancy. It most frequently involves the lung, and in some cases, the lesions are confined to the central nervous system (isolated CNS-LYG). However, it remains a controversial disease in terms of pathophysiology, especially in those confined to the CNS. We report the case of a 37-year-old man with CNS lesion pathologically characterized by angiocentric, T-cell-rich lymphoid cell infiltrates that resembled CNS-LYG. The lesion was clinically aggressive with subacute onset and irregular ring-like enhancement on MRI. The resected specimen showed no cytological atypia, EBV-infected cells, or monoclonality for IgH and TCR gene rearrangements. Considering the possibility of latent malignancy, the patient was successfully treated with corticosteroid and chemoradiotherapy with high-dose methotrexate. The present case and the literature suggest that EBV-negative CNS lesions with angiocentric lymphoid infiltrates are probably heterogeneous in their pathogenesis, including those that could fit into the so-called CNS-LYG and those with T-cell predominance. The accumulation of similar cases is warranted for the classification and appropriate treatment of these lesions.

Meningiomas are the most commonly diagnosed benign intracranial adult tumors. Subsets of meningiomas that present with extensive invasion into surrounding brain areas have high recurrence rates, resulting in difficulties for complete resection, substantially increased mortality of patients, and are therapeutically challenging for neurosurgeons. Exciting new data have provided insights into the understanding of the molecular machinery of invasion. Moreover, clinical trials for several novel approaches have been launched. Here, we will highlight the mechanisms which govern brain invasion and new promising therapeutic approaches for brain-invasive meningiomas, including pharmacological approaches targeting three major aspects of tumor cell invasion: extracellular matrix degradation, cell adhesion, and growth factors, as well as other innovative treatments such as immunotherapy, hormone therapy, Tumor Treating Fields, and biodegradable copolymers (wafers), impregnated chemotherapy. Those ongoing studies can offer more diversified possibilities of potential treatments for brain-invasive meningiomas, and help to increase the survival benefits for patients.

Primary central nervous system lymphoma (PCNSL) is a highly aggressive, extra-nodal non-Hodgkin lymphoma that is confined to the central nervous system (CNS) and the eyes. Most PCNSLs arise in immunocompetent older patients and less frequently in immunocompromised patients with Epstein-Barr virus infection. Although a patient's initial response to chemotherapy and radiation therapy is favorable, the clinical outcome of PCNSL remains poor compared to that of systemic lymphoma. Radiation-induced neurotoxicity is also a critical problem for patients with PCNSL. Therefore, a novel therapeutic strategy is required to overcome these challenges. Recent studies have largely uncovered the genomic landscape and associated histopathological features of PCNSL. Based on this background, novel therapeutic agents, such as Bruton's tyrosine kinase inhibitors and immune checkpoint inhibitors, have been introduced for patients with PCNSL. Here, we provide an overview of the updated histopathological and genomic characterization of PCNSL and summarize the current therapeutic strategies. We also review current preclinical PCNSL models for translational research.

The revised 4th edition of the 2016 World Health Organization Classification of Tumors of the Central Nervous System (2016 CNS WHO) has introduced the integrated diagnostic classification that combines molecular and histological diagnoses for diffuse gliomas. In this study, we evaluated the molecular alterations for consecutive 300 diffuse glioma cases (grade 2, 56; grade 3, 62; grade 4, 182) based on this classification. Mutations in the isocitrate dehydrogenase (IDH) genes were common in lower grade glioma (LGG: grade2-3), and when combined with 1p/19q status, LGGs could be stratified into three groups except for four cases (Astrocytoma, IDH-mutant: 44; Oligodendroglioma, IDH-mutant and 1p/19q codeleted: 37; Astrocytoma, IDH-wildtype: 33). 1p/19q-codeleted oligodendrogliomas were clinically the most favorable subgroup even with upfront chemotherapy. In contrast, IDH-wildtype astrocytomas had a relatively worse prognosis; however, this subgroup was more heterogeneous. Of this subgroup, 11 cases had TERT promoter (pTERT) mutation with shorter overall survival than 12 pTERT-wildtype cases. Additionally, a longitudinal analysis indicated pTERT mutation as early molecular event for gliomagenesis. Therefore, pTERT mutation is critical for the diagnosis of molecular glioblastoma (WHO grade 4), regardless of histological findings, and future treatment strategy should be considered based on the precise molecular analysis.

Detection of BRAF V600E mutation in glioblastomas (GBMs) is important because of potential therapeutic implications. Still, the relative paucity of these mutations makes molecular detection in all GBMs controversial. In the present study, we analyzed clinical, radiographic and pathologic features of 12 BRAF V600E-mutant GBMs and 12 matched controls from 2 institutions. We found that a majority of BRAF V600E-mutant GBMs displayed a combination of well-circumscribed lesions, large cystic components with thin walls and solid cortical component on MRI, but with some overlap with matched BRAF wildtype controls (p = 0.069). BRAF V600E-mutant GBMs were also apt to gross total resection (83% vs 17%, p = 0.016) and morphologically displayed epithelioid features (83% vs 0%, p < 0.0001). Identification of these clinical, radiographic, and pathologic characteristics should prompt testing for BRAF V600E in IDH-wildtype GBM.

Current conventional treatment strategies for glioblastoma (GBM) have limited efficacy due to the rapid development of resistance to temozolomide (TMZ). It is particularly urgent to develop novel therapeutic strategies that can overcome TMZ resistance and provide patients with better prognoses. Here, a TMZ-resistant GBM cell strain and a mouse model of TMZ resistance are established as valuable tools to explore novel therapeutic strategies against TMZ resistance. Experimentally, p38MAPK inhibitor reduces the accumulation of F4/80⁺/CD11b⁺ macrophages/microglia in glioma and prolongs the survivals of glioma-bearing mice. Glioma-associated macrophages/microglia have a significanct expression of PD-L1. p38MAPK inhibitor in combination with PD-L1 antibody can effectively prolongs the survivals of TMZ-resistant GBM-bearing hosts, and differentially reduces the accumulation of circulating monocytes-derived tumor-associated macrophages and PD-L1 abundances of resident glioma-associated microglia. This combination therapy could be a treatment option for patients at the recurrence or chronic TMZ maintenance stages. A clinical study to confirm the safety and effectiveness of this combination therapy is warranted.

Medulloblastoma is a common pediatric malignant brain tumor. There were four consensus molecular subgroups (WNT, SHH, Group3 and Group4). Group 3 and Group 4 tumors exhibited a great degree of transcriptional overlap, and were neither derived from exact pathway aberration. We investigated transcriptional and chromatin accessibility of medulloblastoma by multi-omics single-cell analysis. Our work identified inter- and intra-tumoral heterogeneity within the Group 3, Group 4 and Group 3/4 intermediate subgroups. Unsupervised cluster of each tumor identified 9 cell clusters with transcriptional profiles and 6 cell clusters with chromatin accessibility profiles. OTX2 had the highest activity and expression level across the clusters in a special cluster based on open chromatin single-cell profilings. We identified multiple genes as a significant targeted gene within the OTX2 target genes, which made sense in prognosis. We analyzed the copy-number-variations which presented with expected subgroup distribution from transcriptional and chromatin accessibility profiles. Collectively, these data provide novel insights into Group 3 and Group 4 medulloblastoma and provide a potential therapeutic target.

Rosette-forming glioneuronal tumors (RGNTs) are benign WHO grade 1 tumors that occur in the ventricular system, particularly the fourth ventricle. RGNTs and dysembryoplastic neuroepithelial tumors (DNTs) are both categorized as neuronal and mixed neuronal-glial tumors and may be difficult to distinguish. Coexistence of the two tumor types has been reported. Here, we report a pediatric case of RGNT with DNT-like features showing intraventricular dissemination. The tumor occurred in the medial temporal lobe and presented with specific pathological glioneuronal elements including floating neurons, which are typical in DNTs, but was diagnosed as RGNT because of the presence of neurocytic rosettes. Genetic analysis detected fibroblast growth factor receptor 1 internal tandem duplication (FGFR1-ITD) of the tyrosine kinase domain, which was previously reported to be specific for DNT. RGNTs with FGFR1-ITD may show atypical clinical presentation and pathological features.