Brain Pathology最新文献

An 11-year-old boy was referred to our institution from a resource-limited country with a history of hydrocephalus secondary to a posterior fossa tumor. Magnetic resonance imaging (MRI) revealed a large extra-axial neoplasm located at the tentorium, measuring 5.1 × 4.2 × 4.0 cm (Figure 1), causing marked distortion of the adjacent structures and transtentorial herniation. The lesion was strongly enhancing, associated with massive vasogenic edema. Microsurgical excision of the lesion was performed by a supracerebellar infratentorial approach, obtaining a gross total resection. After recovery, the boy returned to his country, where he has been followed with periodical computed tomography scans. He remains free of disease 58 months from surgery (Box 1).

The lesion consisted of epithelioid and rhabdoid cells arranged in a chordoid pattern within a myxoid stroma (Figure 2A) with foci of collagen deposition sometimes featuring amianthoid fibers (Figure 2B). Solid sheets of rhabdoid and epithelioid cells with focal clear cell changes were also present. Mitotic figures were infrequent (1/1.96 mm²). There was a sparse lymphoplasmocytic inflammatory infiltrate at the periphery. The possibility of a chordoid meningioma was first considered, and the expression of epithelial membrane antigen (EMA) seemed to support this hypothesis. However, given the rarity of this meningioma subtype and the lack of a specific marker, an extensive immunohistochemical panel was performed: the diffuse desmin expression, combined with focal CD99 and D2-40, prompted us to consider an intracranial mesenchymal tumor (IMT) with FET::CREB fusion (Figure 2C–E). RNA sequencing (Agilent) demonstrated the presence of a SMARCA2::CREM transcript (Figure 2F). No pathogenic/likely pathogenic variants were identified (TSO500). CGH/SNP array revealed only a mosaic 12p trisomy. Genome-wide DNA methylation profiling classified the lesion as meningioma (score 0.98), subclass 3 (score 0.93) according to the Heidelberg Brain Tumor Classifier v12.5. t-distributed stochastic neighbor embedding (t-SNE) analysis was performed using selected Deutsches Krebsforschungszentrum (German Cancer Research Center) (DFKZ) reference classes and two previously characterized IMT cases, both harboring an EWSR1::CREM fusion. The current case clustered with one of the IMT and was close to meningiomas, whereas the other IMT was near angiomatoid fibrous histiocytomas (Figure 2G).

IMT harboring a SMARCA2::CREM fusion.

We describe a rare example of a pediatric posterior fossa IMT with a SMARCA2::CREM fusion. A case with an identical fusion transcript has been reported in the parietal lobe of a 40-year-old man with a 15-year history of multiple recurrences of a “chordoid meningioma” [1]. These cases share a striking chordoid morphology. IMT generally shows two main patterns: (i) stellate/spindle cells and abundant myxoid stroma preferentially character

Glioblastomas are known for their immunosuppressive tumor microenvironment, which may explain the failure of most clinical trials in the past decade. Recent studies have emphasized the significance of stratifying glioblastoma patients to predict better therapeutic responses and survival outcomes. This study aims to investigate the prognostic relevance of peripheral immune cell counts sampled prior to surgery, with a special focus on methylation-based subclassification. Peripheral blood was sampled in patients with newly diagnosed (n = 176) and recurrent (n = 41) glioblastoma at the time of surgery and analyzed for neutrophils, monocytes, leukocytes, platelets, neutrophil–lymphocyte ratio, lymphocyte–monocyte ratio, and platelet–lymphocyte ratio. Peripheral immune cell counts were correlated with patients' survival after combined radiochemotherapy. In addition, 850 k genome-wide DNA methylation was assessed on tissue for defining tumor subclasses and performing cell-type deconvolution. In newly diagnosed glioblastoma, patients with higher peripheral neutrophil counts had an unfavorable overall survival (OS) (p = 0.01, median overall-survival (mOS) 17.0 vs. 10.0 months). At the time of first recurrence, a significant decrease of peripheral immune cell counts was observed, and elevated monocyte (p = 0.03), neutrophil (p = 0.04), and platelet (p = 0.01) counts were associated with poorer survival outcomes. DNA methylation subclass-stratified analysis revealed a significant survival influence of neutrophils (p = 0.007) and lymphocytes (p = 0.04) in the mesenchymal (MES) subclass. Integrating deconvolution of matched tumor tissue showed that platelets and monocytes were correlated with a more differentiated, tumor-progressive cell state, and peripheral immune cell counts were most accurately reflected in tissue of the MES subclass. This study illustrates a restricted prognostic significance of peripheral immune cell counts in newly diagnosed glioblastoma and a constrained representation in matched tumor tissue, but it demonstrates a more pertinent situation at the time of recurrence and after DNA methylation-based stratification.

Oxidized regenerated cellulose (ORC; marketed as Surgicel® and Tabotamp®) is routinely used as an intraoperative hemostatic agent. Rarely, residual ORC has been associated with a foreign body reaction generating cystic or granulomatous lesions (i.e., textilomas) at the surgical site. Here, we report a bedside-to-bench, translational report of an intracranial mass after neurosurgical resection of glioblastoma with ORC application. As part of patient care, we performed magnetic resonance imaging and histopathological analysis of the mass. We then performed in vitro studies to evaluate the effect of ORC on cytokine production and viability of BV-2 murine microglial cells by using quantitative PCR along with live cell microscopy and crystal violet staining, respectively. Magnetic resonance imaging demonstrated a recurrent mass pressing on the adjacent right ventricle, which was removed in a second surgery for diagnostic and therapeutic purposes. Unexpectedly, histopathological examination of the resected mass revealed abundant ORC arising from the site with inflammation, microglial activation, and collagenization. Mechanistically, we show an ORC-induced modest increase in inflammatory cytokines with a subsequent decrease in microglial cell viability. These findings suggest that ORC may mediate microglial immune response and viability, and serve to raise awareness and guide interpretation of post-treatment surveillance imaging findings in the instance of foreign body reaction.

The shift toward a histo-molecular approach in World Health Organization classification of central nervous system tumors (WHO CNS5) emphasizes the critical role of molecular testing, such as next-generation sequencing (NGS) and DNA methylation profiling, for accurate diagnosis. However, implementing these advanced techniques is particularly challenging in resource-constrained countries. To address this, the Asian Oceanian Society of Neuropathology committee for Adapting Diagnostic Approaches for Practical Taxonomy in Resource-Restrained Regions (AOSNP-ADAPTR) was initiated to help pathologists in resource-limited regions to implement WHO CNS5 diagnoses using simpler diagnostic tools, mainly immunohistochemistry. An online survey by this group assessed the in-house/local availability of diagnostic resources and outsourcing capabilities across the Asian Oceanian region, covering 19 countries. Of 318 responding centers, the availability of molecular techniques in-house/locally was limited in lower middle-income countries (LMICs), with 29% having fluorescence in situ hybridization, 10.7% Sanger sequencing, and only 9.4% NGS. DNA methylation was largely unavailable in-house/locally in of LMICs, while in the whole region, its availability stood at a meager 4.4%. Though outsourcing for all diagnostic tests was an easily accessible alternative, outsourcing for NGS and DNA methylation was uncommon because of the financial burden on patients being a significant obstacle. The survey categorized centers into five resource levels (RLs) based on the in-house/local access to diagnostic techniques, which highlighted the variability and disparity in diagnostic capabilities across the region. High-income countries had 80% of centers with advanced RL IV, V resources, in contrast to LMICs, where 70.5% of centers fell into RL I–III. This comprehensive evaluation emphasizes the need for tailored resource level guidelines, with the aim of improving diagnostic accuracy and treatment as well as advocating better healthcare infrastructure in resource-constrained areas. However, the survey's reliance on responses from better-resourced centers may underestimate challenges in lower-resource settings, stressing the need for broader outreach and support.

The last pregnancy trimester is critical for fetal brain development but is a vulnerable period if the pregnancy is compromised by fetal growth restriction (FGR). The impact of FGR on the maturational development of neuronal morphology is not known, however, studies in fetal sheep allow longitudinal analysis in a long gestation species. Here we compared hippocampal neuron dendritogenesis in FGR and control fetal sheep at three timepoints equivalent to the third trimester of pregnancy, complemented by magnetic resonance image for brain volume, and electrophysiology for synaptic function. We hypothesized that the trajectory of hippocampal neuronal dendrite outgrowth would be decreased in the growth-restricted fetus, with implications for hippocampal volume, connectivity, and function. In control animals, total dendrite length increased with advancing gestation, but not in FGR, resulting in a significantly reduced trajectory of dendrite outgrowth in FGR fetuses for total length, branching, and complexity. Ex vivo electrophysiology analysis shows that paired-pulse facilitation was reduced in FGR compared to controls for cornu ammonis 1 hippocampal outputs, reflecting synaptic dysfunction. Hippocampal brain-derived neurotrophic factor density decreased over late gestation in FGR fetuses but not in controls. This study reveals that FGR is associated with a significant deviation in the trajectory of dendrite outgrowth of hippocampal neurons. Where dendrite length significantly increased over the third trimester of pregnancy in control brains, there was no corresponding increase over time in FGR brains, and the trajectory of dendrite outgrowth in FGR offspring was significantly reduced compared to controls. Reduced hippocampal dendritogenesis in FGR offspring has severe implications for the development of hippocampal connectivity and long-term function.

Amyotrophic lateral sclerosis (ALS) is a fatal neuromuscular disease with no effective treatments, in part caused by variations in progression and the absence of biomarkers. Mice carrying the SOD1G93A transgene with different genetic backgrounds show variable disease rates, reflecting the diversity of patients. While extensive research has been done on the involvement of the central nervous system, the role of skeletal muscle remains underexplored. We examined the impact of angiogenin, including its RNase activity, in skeletal muscles of ALS mouse models and in biopsies from ALS patients. Elevated levels of angiogenin were found in slowly progressing mice but not in rapidly progressing mice, correlating with increased muscle regeneration and vascularisation. In patients, higher levels of angiogenin in skeletal muscles correlated with milder disease. Mechanistically, angiogenin promotes muscle regeneration and vascularisation through satellite cell-endothelial interactions during myogenesis and angiogenesis. Furthermore, specific angiogenin-derived tiRNAs were upregulated in slowly progressing mice, suggesting their role in mediating the effects of angiogenin. These findings highlight angiogenin and its tiRNAs as potential prognostic markers and therapeutic targets for ALS, offering avenues for patient stratification and interventions to mitigate disease progression by promoting muscle regeneration.

Brain injury represents the leading cause of mortality and disability after cardiopulmonary resuscitation (CPR) from cardiac arrest (CA), in which the accumulation of dying cells aggravate tissue injury by releasing proinflammatory intracellular components. Microglia play an essential role in maintaining brain homeostasis via milk fat globule epidermal growth factor 8 (MFG-E8)-opsonized efferocytosis, the engulfment of dying cells and debris. This study investigates whether potentiating microglia efferocytosis by MFG-E8 provides neuroprotection after CA/CPR. After 8-minute asphyxial CA/CPR, male adult C57BL/6J mice were randomly assigned to receive recombinant mouse MFG-E8 (rmMFG-E8) or vehicle. We evaluated the survival and neurological deficits of mice, along with histological damages, phagocytosis index of dying cells, and microglia polarization. A transcriptome analysis was conducted to explore the downstream molecules modulated by MFG-E8. In mice resuscitated from CA, rmMFG-E8 administration significantly enhanced the efferocytosis of apoptotic cells by microglia, improved the survival and neurological function of mice, and attenuated neuropathological injuries. Additionally, rmMFG-E8 induced a prominent alteration in microglial gene expression and promoted a shift from a proinflammatory phenotype to an anti-inflammatory phenotype. Moreover, rmMFG-E8 treatment induced up-regulation of interferon regulatory factor 7 (IRF7), and IRF7 gene silencing largely reversed the neuroprotective effects of rmMFG-E8. This study demonstrates that rmMFG-E8 improves survival and neurological outcomes after CA/CPR by enhancing microglial efferocytosis and reshaping the inflammatory microenvironment in brain tissue. Potentiating MFG-E8 is a promising strategy to combat post-CA brain injury.

Adult primary leptomeningeal gliomatosis (PLG) is a rare, rapidly progressive and fatal disease characterized by prominent leptomeningeal infiltration by a glial tumor without an identifiable parenchymal mass. The molecular profile of adult PLG has not been well-characterized. We report the clinical, pathological, and molecular findings of six adult PLG patients (five males and one female), median age 58 years. All cases exhibited pathological leptomeningeal enhancement at presentation. Leptomeningeal biopsy was diagnostic in five (of six) cases, revealing infiltration by an astrocytic glioma with mitotic activity, lacking microvascular proliferation or necrosis. One case was diagnosed at autopsy. All tumors were IDH-wildtype, with five harboring TERT promoter mutations. Additional mutations identified were PTEN in one case, TP53 in two cases, and NF1 in two cases. A chromosome profile with +7/−10 was found in four cases, whereas the remaining two showed either chromosome 7 or 7p gain only. Four cases showed chromosome 9p loss with CDKN2A/B homozygous deletion, one case showed hemizygous CDKN2A/B loss, and one case showed intact chromosome 9 and CDK4/GLI1 amplification. DNA methylation profiling was performed in four cases and revealed a match to glioblastoma (GBM) family and mesenchymal typical class with high confidence scores in two cases; the other two cases showed only suggestive combined scores for GBM family and mesenchymal atypical class. The molecular profile of all cases closely aligned with that of adult-type GBM, IDH-wildtype, CNS WHO grade 4. All patients succumbed to the disease. In five cases with extensive leptomeningeal disease at diagnosis, the course was rapid, with median survival of 24 days following palliative care. Only one case, with relatively localized disease at diagnosis, received chemoradiation therapy and survived 535 days, raising the possibility that early diagnosis and timely treatment could improve outcome. A detailed list of previously reported cases is provided in a supplementary table.