Neuropathology最新文献

Spinal astroblastoma is an exceedingly rare entity characterized by features that overlap with other spinal cord tumors. We present a case of a 67-year-old male who presented with trunk dysesthesia, motor weakness, and progressive hypoesthesia in both lower limbs. Magnetic resonance imaging (MRI) revealed edematous changes in the spinal cord at the C6-Th1 level on T2-weighted sequences, with a centrally enhancing lesion at the C7 level on gadolinium-enhanced T1-weighted imaging. Consistent with previous reports, spinal astroblastomas frequently involve the cervical and thoracic regions. Pathological examination in our case revealed pseudopapillary cellular arrangements surrounding hyalinized microvasculature. Immunohistochemical analysis demonstrated retained INI1/SMARCB1 expression and mixed-origin features, with positive staining for EMA, GFAP, OLIG2, neurofilament, and synaptophysin. The tumor exhibited low-grade characteristics, with no mitotic activity, necrosis, or significant MIB-1 index (0.3%), and followed a gradual clinical course. Genetic profiling revealed no MN1 alteration or fusion genes. Based on these findings, a diagnosis of low-grade spinal astroblastoma, not elsewhere classified, was made. In conclusion, spinal astroblastoma should be considered in the differential diagnosis of primary intramedullary spinal cord tumors, particularly those located in the cervicothoracic region and exhibiting mixed-origin features. The sharing of cases among clinicians is crucial for enhancing awareness and understanding of this rare pathology.

Peripheral nerve injuries (PNI) cause a partial or total deficit of sensory and motor function, producing neuropathic pain and loss of productivity in adults. Type I collagen polymerized with polyvinylpyrrolidone (CLG-PVP) has been used previously in other fibrosing diseases due to its regulatory effects on interleukins, cytokines, and adhesion molecules. In the present study, we describe the role of CLG-PVP in the repair of PNI. We used a murine model of PNI through axonotmesis of the sciatic nerve. CLG-PVP treatments were administered in situ and intramuscularly and were compared to a sham procedure and placebo. Histological and histochemical-specific stain evaluations were performed to describe the structural changes in nervous tissue. A significant reduction in tissue fibrosis was observed in the groups treated with CLG-PVP, especially with the intramuscular treatment. Likewise, an increase in the organization of external lamina and nerve remyelination was observed in the treated groups. In addition, a slight improvement in gait was noted in the treated animal groups at the end of the study. After peripheral nerve injury, CLG-PVP restores the nerve's function, structure, and tissue organization. These therapeutic effects were more evident through the intramuscular administration scheme with a weekly dosage. However, randomized controlled clinical trials should be performed to verify its beneficial effects and characterize adverse events.

Ependymomas are categorized based on anatomical location and specific genetic alterations, with extra-axial metastasis being a rare event, occurring in less than 1% of cases and documented sparsely in the literature. This case study details a 27-year-old male patient diagnosed with supratentorial ependymoma characterized by Zinc Finger Translocation Associated (ZFTA) fusion and World Health Organization (WHO) Grade 2 morphology. Additionally, a systematic review of all reported cases of extra-axial ependymoma metastases was conducted, systematically compiling clinical, morphological, and molecular data from relevant articles. Metastatic ependymoma represents a rare occurrence characterized by diagnostic and therapeutic challenges. A comprehensive review of the literature could provide valuable insights into the underlying biology and support the selection of optimal treatment strategies for such cases.

Angiocentric glioma (AG) is a supratentorial diffuse low-grade glioma characterized by the MYB::QKI fusion gene, showing angiocentric growth of monomorphous spindle cells with astrocytic and ependymal immunophenotypes. We describe a rare case of MYB::QKI fusion-positive diffuse cerebellar glioma in a 54-year-old male. The patient initially presented with a T2/FLAIR hyperintense lesion in the left cerebellar hemisphere and slowly progressive neurological symptoms. Histopathological evaluation revealed a diffuse glioma characterized by spindle-shaped and small epithelioid cells with perivascular infiltration. Immunohistochemistry showed positivity for glial fibrillary acidic protein and only occasionally positive for Olig2. No dot- or ring-like epithelial membrane antigen immunoreactivity was observed. In this case, the proliferative activity was higher than that in typical AG cases, as manifested by multiple mitoses (four mitoses/slide) and a Ki-67 labeling index of 5%. The tumor cells were negative for IDH1 p.R132H and H3 p.K28M mutation-specific antibodies. Fluorescence in situ hybridization showed a MYB break-apart signal, and reverse transcription-polymerase chain reaction analysis confirmed an in-frame MYB (6q23.3, exon 11, NM_001161659.2)::QKI (6q26, exon 5, NM_006775.3) fusion. IDH1 p.R132, IDH2 p.R172, H3-3A p.K28, H3C2 p.K28, and BRAF p.V600 were all wild type. DNA methylome profiling did not match any of the established methylation classes, including the four subtypes of diffuse glioma, MYB- or MYBL1-altered. Considering the results of DNA methylome profiling, the question remains as to whether this case represents a subset of AG (diffuse glioma, MYB/MYBL1-altered) or a distinct subtype. Although the morphological findings and the presence of fusion indicated that the tumor was a cerebellar AG, the DNA methylome profile did not match that of AG. An accumulation of more cases is needed to determine the precise nature of the tumor, which may lead to an expansion of the tumor concept.

The choroid plexus not only secretes the majority of cerebrospinal fluid but also controls the circadian rhythm, which can be impaired in the presence of neurodegenerative diseases. In addition, many studies have reported the contribution of choroid plexus abnormalities to the pathogenesis of neurodegenerative diseases, including Alzheimer's disease (AD). Formalin-fixed paraffin-embedded blocks were obtained from the lateral ventricles of the brains of four subjects with AD, four with vascular dementia, four with Parkinson's disease, three with multiple system atrophy, and five control patients with unremarkable neuropathological findings. They were sectioned and routinely stained with hematoxylin and eosin. Morphological analysis of epithelial cells in 10 high-power fields or a total area per case was conducted using digital images. There were no significant changes in any of the measurements: epithelial cell area, long and short axes, and ratio of the epithelial cell area to total stained area among the five groups. However, a simple linear regression analysis of epithelial cells in 20 patients showed that age was significantly correlated with the cell area, long axis, and short axis but not ratio. There were no effects of hypertension, diabetes mellitus, or calcification in the stroma on the measurements. These findings indicate that age was associated with the cell area and size in choroid plexus epithelial cells, whereas no significant changes in any epithelial cell measurements were present in neurodegenerative diseases.

Oxidative stress in sporadic amyotrophic lateral sclerosis (ALS) has been evidenced by accumulation of oxidatively modified products of nucleic acids, lipids, sugars, and proteins in the motor neuron system of brains and spinal cords obtained at autopsy from the patients. We recently demonstrated soluble iron accumulation in activated microglia of sporadic ALS spinal cords. This finding could indicate that iron-mediated Fenton reaction is most likely to be responsible for oxidative stress associated with this disease. The excitatory amino acid neurotoxicity hypothesis for sporadic ALS has been proposed based on increased glutamate and aspartate concentrations in cerebrospinal fluid from the patients. Initially, the increase in extracellular excitatory amino acid levels was considered to reflect excessive release from the axon terminal of upper motor neurons. However, it is a question of whether the damaged upper motor neurons continue releasing glutamate even in advanced stage of this disease. To address this issue, we hypothesized that glial cells might be a glutamate release source. Our immunohistochemical analysis on autopsied human spinal cords revealed that ferritin, hepcidin, ferroportin, aconitase 1, tumor necrosis factor-α (TNF-α), TNF-α-converting enzyme (TACE), and glutaminase-C (GAC) were expressed mainly in microglia and that cystine/glutamate antiporter (xCT) was expressed mainly in astrocytes. We next performed cell culture experiments. Cultured microglia treated with soluble iron over-released glutamate and TNF-α via aconitase 1 and TACE, respectively. Cultured microglia treated with TNF-α over-released glutamate via GAC. Cultured microglia treated with hepcidin, of which expression is known to be upregulated by TNF-α, showed downregulated expression of ferroportin. Cultured astrocytes treated with hydrogen peroxide over-released glutamate via xCT. These observations provide in vivo and in vitro evidence that microglia and astrocytes are glutamate suppliers in response to soluble iron overload and oxidative stress, respectively, in sporadic ALS.

This report details a rare case of a 30-year-old female presenting with neurological symptoms, including headaches, seizures, and left-sided weakness. Imaging revealed a mass in the right parafalcine region of her brain. Surgical resection identified a tumor with two distinct components. The first component exhibited characteristics of a classic solitary fibrous tumor (SFT) with typical fibroblastic cells and branching blood vessels. The second component showed high-grade sarcoma with chondrosarcomatous differentiation, a rare feature in SFT. Immunohistochemistry confirmed dedifferentiation with decreased STAT6 expression in the sarcomatous areas compared to the conventional SFT. This case highlights the challenges of managing dedifferentiated SFTs, especially in the brain, where surgical limitations increase risks. Despite the rarity of this presentation, it emphasizes the importance of recognizing this variant for appropriate diagnosis and management.

Multiple system atrophy (MSA) is a rare neurodegenerative disease characterized by an accumulation of phosphorylated α-synuclein (p-αsyn) in oligodendrocytes in the form of glial cytoplasmic inclusions (GCIs). In MSA, not only mature oligodendrocytes but also oligodendrocyte precursor cells (OPCs) are affected. The latter play an important role in remyelination by differentiating into mature oligodendrocytes, as well as maintaining the blood-brain barrier (BBB) by promoting the expression of tight junction proteins. We have hypothesized that in MSA, the BBB is impaired as a result of aberrant interactions between affected OPCs and the cerebral vasculature. To verify this hypothesis, we conducted a neuropathological examination of postmortem brains from MSA patients and control subjects, focusing on the primary motor area, one of the main regions affected in MSA. Using double immunofluorescence, we quantified the expression of tight junction protein claudin-5 in capillary endothelial cells and found that it was significantly lower in MSA than in controls in both the gray matter and white matter. Furthermore, a significantly higher amount of fibrinogen was extravasated into the brain parenchyma in MSA patients than in controls. In addition, leakage of IgG was detected almost specifically in MSA brain parenchyma, as visualized in three dimensions by combining techniques of chemical tissue clearing and light sheet microscopy. Finally, we confirmed accumulation of p-αsyn-positive GCIs along the cerebral vasculature within OPCs. These results suggest that BBB dysfunction and associated fibrinogen extravasation are constant findings in MSA, presumably triggered by the deposition of p-αsyn in perivascular OPCs.

Most cases of dementia with Lewy bodies (DLB) follow a chronic course. However, some cases of rapidly progressive dementia (RPD) are difficult to distinguish from other diseases. Herein, we report how to differentiate DLB presenting with RPD from other diseases and its pathological features, with examples from our own experience. A 70-year-old man with RPD and psychiatric symptoms, including hallucinations and delusions, was transferred to our hospital. We suspected Creutzfeldt-Jakob disease (CJD), but disease-specific tests were all negative. The patient was treated with corticosteroids on the suspicion of an autoimmune condition; however, his symptoms did not improve. Based on the results of nuclear medicine and other tests, we suspected DLB and administered anti-Parkinsonian drugs; however, they were ineffective, and the patient died. Brain autopsy revealed extensive deposits of Lewy bodies, which were pathologically diagnosed as DLB. Additionally, extensive deposition of senile plaques was observed; however, neurofibrillary tangles (NFTs) were not prominent. DLB generally presents as a chronic disease. However, some patients with DLB present with RPD; therefore, the differential diagnosis of other diseases, such as CJD, is very important. In addition, although this case was not diagnosed with Alzheimer's disease (AD) due to the lack of NFTs, extensive amyloid deposition was observed in the brain tissue. Previous reports have described cases of RPD with amyloid deposition alone, and in this case too, it is suggested that amyloid deposition might have had a strong influence on the clinical course of RPD.