The case of a 75-year-old man with a glioblastoma of the right frontal lobe showing features of adenoid glioblastoma is reported. The tumor consisted of two components: the adenoid component, in which large, cohesive, polygonal cells with vesicular nuclei and abundant basophilic cytoplasm showed nest-like, trabecular, or tubular growth on the myxoid matrix and formed a multinodular configuration; and the subsidiary component, in which short spindle cells showed compact fascicular growth. The features of ordinary glioblastoma were also found in a small area. Tumor cells were immunoreactive for S-100 protein, glial fibrillary acidic protein, and Olig2, and some tumor cells in the adenoid component showed immunoreactivity for cytokeratins and E-cadherin. A marked regional decrease in microvascular density, approaching almost complete absence of microvessels, was demonstrated in the adenoid component. In contrast, microvascular density was well preserved in the spindle cell component and the area of ordinary glioblastoma. Tumor cells in the adenoid component showed cytoplasmic expression of chondromodulin-I, one of the cytokines that strongly inhibit angiogenesis, whereas the expression of this protein was very weak or only faint in the spindle cell component and the area of ordinary glioblastoma. A marked regional decrease in microvascular density was associated with myxoid change of the stroma and considered to be caused by the secretion of chondromodulin-I by tumor cells. Stromal hypovascularity with myxoid change might play an important role in the morphogenesis of adenoid features.

We report a patient who presented clinically with progressive supranuclear palsy (PSP) but was pathologically diagnosed as having primary lateral sclerosis (PLS) with magnetic resonance imaging (MRI) with a quantitative susceptibility mapping (QSM) protocol. A 70-year-old man was clinically diagnosed with PSP due to early falls and unresponsiveness to levodopa therapy. Postmortem pathological examination revealed mild loss of Betz cells, gliosis, and transactive response DNA binding protein of 43 kDa (TDP-43)-positive inclusions in the motor cortex, leading to the pathological diagnosis of PLS. To explore methods for differentiating PLS from PSP, ante-mortem QSM images were visually and quantitatively assessed for abnormal increases in magnetic susceptibility in the motor cortex. Prussian blue and Luxol fast blue combined with periodic acid-Schiff staining were also performed to understand the source of the susceptibility increases. QSM showed clear hyperintense signals in the motor cortex. Magnetic susceptibility in the motor cortex was higher in the PLS patient (Z = 4.7, p < 0.001) compared to normal controls and pathologically diagnosed PSP patients. Pathological examination of the region showed intracortical myelin loss, as well as iron deposition. Underlying pathological processes for the increased magnetic susceptibility include not only iron deposition but also intracortical myelin. Our case suggests that QSM is a potential tool to differentiate PLS from PSP, providing insights for accurate diagnosis and enhancing clinical decision-making.

Subependymal giant cell astrocytoma (SEGA) is a rare, low-grade glioma typically associated with tuberous sclerosis (TS) and mutations in the TSC1 or TSC2 genes. It is characterized by an intraventricular location, an expansive growth pattern, and the expression of glial and neural markers. TTF-1 expression is considered a sensitive marker of SEGA, likely reflecting its origin from progenitor cells in the caudothalamic groove. We report a case of SEGA with unusual immunohistochemical and molecular features in a 20-year-old man with no signs or family history of TS. The tumor was located in the anterior horn of the right ventricle and obstructed the foramen of Monro. Histologically, it exhibited an expansive growth pattern and was composed of cells with ovoid nuclei and abundant eosinophilic cytoplasm. Immunohistochemically, the tumor cells were positive for GFAP and S-100 protein, weakly positive for SOX2, focally positive for synaptophysin, and negative for TTF-1, neurofilament protein, NeuN, EMA, chromogranin, and BCOR. Scattered OLIG2-positive neoplastic cells were also observed. Molecular analysis revealed no pathogenic mutations or copy number variations in the analyzed 174 genes, including TSC1/2, except for a variant of unknown significance in BAP1. The histopathological features and immunohistochemical profile suggested SEGA, despite the absence of TTF-1 expression and TSC1/2 mutations. The diagnosis was confirmed by DNA methylation profiling, which assigned the tumor to the methylation class "subependymal giant cell astrocytoma with TSC1/TSC2 alterations" with a calibrated score of 0.95. This case highlights the potential diagnostic pitfall of SEGA lacking TTF-1 expression and emphasizes the importance of considering this entity in the differential diagnosis of intraventricular tumors, even in the absence of TS and characteristic molecular alterations. The existence of TTF-1 negative SEGAs reveals that these tumors might also derive from TTF-1 negative cells in the subpendymal region.

Primary intracranial sarcomas constitute a rare group of tumors, with the most common types described in the literature being chondrosarcoma and fibrosarcoma. Dedifferentiated liposarcoma (DDLS) is a high-grade sarcoma that sometimes metastasizes to the brain. However, a primary intracranial DDLS is exceedingly rare. A 45-year-old patient from the Middle East came to India for treatment. His magnetic resonance imaging (MRI) scans revealed a space-occupying lesion at the level of the lateral ventricle T2/fluid attenuated inversion recovery hyperintensity with peripheral edema. A T1 perfusion map showed high relative cerebral blood volume values in the peripheral part, suggesting a high-grade neoplasm. Gross total resection was performed, and histopathology showed a high-grade tumor composed of sheets of pleomorphic lipoblasts and epithelioid tumor cells arranged in nests and cords. Immunohistochemistry showed diffuse immunopositivity for MDM2, CDK4, and p16, while GFAP and OLIG2 were negative. Fluorescence in situ hybridization showed MDM2 amplification. Final diagnosis of DDLS was rendered. The patient had no systemic lesions elsewhere on positron emission tomography computed tomography scan.

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.

Germ cell tumors (GCTs) are categorized as gonadal or extra-gonadal, based on the origin. Extra-gonadal GCTs predominantly manifest within the central nervous system (CNS), mediastinum, retroperitoneum, and sacrococcygeal region. These malignancies are most frequently diagnosed in the pediatric, adolescent, and young adult demographics. Incidences of GCT within the nasal cavity are notably scarce, with only six cases documented. This report details the case of a 70-year-old man who presented with a left nasal mass ultimately diagnosed as immature teratoma. A remarkable aspect of this case was the detection of SMARCA4 (BRG1) loss through immunohistochemical analysis. In addition, methylation profiling aligned this case with CNS GCTs, specifically those classified as non-germinomatous GCTs. This molecular characterization informed a tailored therapeutic strategy incorporating carboplatin and etoposide, alongside localized irradiation. This individualized treatment regimen achieved favorable outcomes, with the patient remaining recurrence free for over three years. This highlights the need for precise therapeutic approaches in the management of extragonadal GCTs, particularly those arising in atypical anatomical locations. The present case accentuates the significance of thorough diagnostic evaluations and customized treatment plans for rare GCT presentations. Further empirical and clinical investigations are warranted to enhance our understanding of and refine therapeutic protocols for such exceptional cases.

Ovarian mature teratomas frequently contain central nervous system (CNS) tissue that often exhibits a variety of neuropathologic alterations. The author systematically examined the changes seen in CNS tissue from a series of 251 cases of resected ovarian mature teratomas. A total of 101 (40.2%) samples contained CNS tissue in varying amounts. The principal pathologic findings in the CNS tissue from ovarian mature teratomas were as follows: (i) CNS tissue tended to form a relatively thin, undulating, plate-like structure that comprised the walls or septa of cystic tumors; (ii) most neurons were small or medium sized, and no CD34-positive "ramifying cells" were observed; (iii) cytoplasmic processes of some astrocytes closely surrounded the walls of capillaries, suggesting formation of a blood-brain barrier; (iv) some ependymal cells exhibited a columnar shape and showed a pseudostratified arrangement, and these cells extended thick basal cytoplasmic processes into the neuropil; (v) a few choroid plexus epithelial cells showed melanin deposition, tubular transformation, or oncocytic changes; (vi) hamartoma-like hyperplasia of arachnoid cells was noted beneath skin tissue; (vii) some CNS tissue showed formation of cerebral cortical structures exhibiting "gyration" with incompletely layered structures, and disruption of the glia limitans with spillage of cortical tissue into the "subarachnoid" space was also observed; and (viii) in the well-formed cerebellar cortex, dendrites of Purkinje cells exhibited varied dysmorphic changes. These neuropathologic observations should lead to a deeper understanding of the pathogenesis of various lesions in the brain.

Hereditary spastic paraplegia (HSP) with thin corpus callosum can be due to a variety of genetic causes, the most common of which are biallelic variants in SPG11 (HSP11). Only six cases of neuropathologic examination of HSP11 have been reported. Here we present neuropathological findings in another case of HSP11 with novel mutation (homozygous c.6439_6442del) and clinical features of three additional cases of HSP11. These four cases of HSP11 had similar disease courses with prominent lower extremity weakness and spasticity but varied cognitive symptoms and brain magnetic resonance imaging (MRI) findings. Neuropathological examination of one case included ex vivo MRI of the cerebrum, histologic and immunohistochemical evaluation, and Western blot for SPG11. The case was notable for a small cerebrum with decreased volume of cortex, white matter, and deep gray nuclei. The corpus callosum was thin, and the substantia nigra showed marked pallor. Microscopically, the cortex had normal lamination and mild loss of neurons with mild gliosis, the corpus callosum was thin with limited gliosis, and the substantia nigra had marked decrease in neurons and pigment, with minimal gliosis. In contrast, the basal ganglia, thalamus, and spinal cord (anterior horns, corticospinal, and spinocerebellar tracts) had prominent neuron loss and gliosis. Myelin-laden macrophages were found in multiple sites but were most common in the corpus callosum. No hyperphosphorylated tau or TDP-43 aggregates, Lewy bodies, or amyloid β plaques were found. Compared to control, SPG11 was absent in HSP11 brain and markers of autophagy were elevated by Western blot. Comparison with prior reports of HSP with thin corpus callosum and HSP11 demonstrates a disease with a broad range of structural changes of the brain, including features of abnormal development and degeneration.

Here, we report a case of antineutrophil cytoplasmic antibody (ANCA)-associated central nervous system (CNS) vasculitis that mimicked a brain tumor. The patient presented with progressive right upper arm weakness. Brain magnetic resonance imaging (MRI) revealed large tumor-like lesions in the left frontal and parietal lobes, with patchy and irregular enhancement with gadolinium and edema. Based on the clinical course and radiological findings, a brain tumor was suspected, and stereotactic brain biopsy was performed. Brain histopathology revealed necrotic tissue and lymphocyte infiltration around small vessels and blood vessel walls. Although the patient's clinical course and pathological findings suggested primary angiitis of CNS (PACNS), double staining for myeloperoxidase (MPO) and CD31 (a neutrophil marker) revealed infiltration of MPO-positive neutrophils in the blood vessel walls. Therefore, we diagnosed the patient with ANCA-associated CNS vasculitis. Because CNS vasculitis, including PACNS, presents nonspecific clinical findings and can depict brain tumor-like MRI findings, CNS vasculitis should be carefully differentiated from brain tumors. Additionally, double staining for MPO and CD31 might be useful for evaluating the pathogenesis of CNS vasculitis.

Clinical diagnosis of progressive supranuclear palsy (PSP) is difficult due to various phenotypes. Neuropathologically, PSP is defined by neuronal loss in the basal ganglia and brainstem with widespread occurrence of neurofibrillary tangles (NFTs) and accumulation of phosphorylated tau protein in neurons and glial cells in the brain. We previously identified the point mutation p.Pro3866Ala in the Bassoon (BSN) gene in a Japanese family with PSP-like syndrome. We newly detected BSN mutations in two autopsied PSP cases carrying p.Thr2542Met and p.Glu2759Gly, respectively. The case with p.Thr2542Met mutation showed neurological symptoms including behavioral abnormalities, cognitive dysfunction, and parkinsonism. Brain magnetic resonance imaging (MRI) showed atrophy of the midbrain tegmentum and hippocampus. Pathologically, moderate to severe loss of neurons with gliosis was also found in the substantia nigra, and there was an almost complete loss of neurons with gliosis in the transitional zone of the cornu ammonis (CA) 1 region to the subiculum. NFTs were observed in the globus pallidus, subthalamic nucleus, substantia nigra, and CA1. 4R tau-dominant tauopathy was detected. The case with p.Glu2759Gly mutation showed neurological symptoms, including right-dominant motor impairment, right limping gait, postural instability, and cognitive dysfunction. Brain MRI showed mild atrophy of the midbrain tegmentum and left-dominant parietal lobe atrophy. Pathologically, NFTs were detected in the globus pallidus, subthalamic nucleus, substantia nigra, thalamus, putamen, and brainstem tegmentum. Most neurons were immunopositive for four-repeat tau, whereas only a few of them harbored three-repeat tau-positive NFTs in the hippocampus. We showed the results of a pathological study of PSP cases with BSN mutations; these were two new cases. The clinical phenotypes were similar to the first case in the point of neurological symptoms. Accumulation of four-repeat tau was dominant. Further autopsies of BSN mutation cases and further elucidation of the molecular biological mechanism are desirable.

Guillain-Barré syndrome (GBS) is an acute disorder of the peripheral nervous system, causing flaccid paralysis, areflexia, and variable sensory involvement. Proximal as well distal muscles of the limbs can be involved, and in most severe and advanced cases progresses to respiratory failure and death. GBS is considered an autoimmune disease, and at the basis of the attack at the peripheral nervous system different mechanisms have been recognized, in particular viral infections or other immune stimulations. Cranial nerve involvement in patients with diffuse large B-cell lymphoma (DLBCL) and primary central nervous system lymphoma are rare conditions that could present with similar clinical features. Here we present a case of a 36-year-old man hospitalized for acute polyradiculoneuritis of the cranial nerves and lumbar roots that arose a 14 days after severe acute respiratory syndrome COVID-19 2 (Sars-CoV-2) vaccination. Most of the main criteria for the diagnosis of GBS were met, including clinical and electrophysiological criteria. Albuminocytologic dissociation and high protein level in cerebrospinal fluid were also found. Therefore, the patient was treated with a cycle of intravenous immunoglobulin (IVIG) with notable improvement of symptoms and gradual recovery of motility. A five months later, following SARS-CoV-2 infection, the patient presented with worsening of neurological symptoms and was readmitted to the hospital. He underwent instrumental tests again and was treated with repeated cycles of IVIG and then with a cycle of plasmapheresis without any improvement. In the following 10 days he developed very serious conditions; he was transferred to intensive care unit and deceased after 6 days. The cause of the neurological syndrome was determined only after autoptic analysis, which revealed the presence of primary peripheral nervous system (PNS) DLBCL. The reported case highlights that GBS-like presentation always requires a careful differential diagnosis, and physicians should also consider the possibility of an occult cancer.

In the fifth edition of the World Health Organization's (WHO) classification of tumors of the central nervous system (CNS), molecular analysis is required for not only determining each tumor type but assessing its prognosis based on malignancy (CNS WHO grade). A notable example is the loss of tumor suppressor gene cyclin-dependent kinase inhibitor 2A (CDKN2A), and CDKN2A homozygous deletion (HD) is a novel CNS WHO grade 4 marker in isocitrate dehydrogenase gene (IDH)-mutant astrocytoma. However, incorporating molecular workup into the "routine diagnostics" of each brain tumor type remains a major challenge, especially in resource-limited settings, including low- and middle-income countries. We herein validated the usefulness of p16 and methylthioadenosine phosphorylase (MTAP) immunohistochemistry (IHC) as potential surrogates for the assessment of CDKN2A status in 20 IDH-mutant astrocytoma cases. Of note, loss or retention of p16 and MTAP could accurately predict CDKN2A HD (p16: 87.5%, MTAP: 88.9%) or non-HD (p16: 100%, MTAP: 100%) with a single marker alone. Importantly, we revealed contributing factors to gray-zone IHC results (p16: 5-20%, MTAP: mosaic), including (1) hemizygous deletion of CDKN2A, (2) degenerative findings, and (3) intratumoral CDKN2A HD heterogeneity, the detailed histologic and molecular assessment of which would be a key to achieving integrated assessment of malignancy in IDH-mutant astrocytoma. We characterized the pitfalls of each method and provided for the first time a practical flowchart of astrocytoma grading, contributing to a normalization of WHO2021-based molecular diagnostics in resource-limited settings.

We describe the case of a 70-year-old Japanese man with familial amyotrophic lateral sclerosis (fALS) associated with a p.Gly93Ser mutation in the copper/zinc superoxide dismutase (SOD1) gene. This mutation is one of the relatively rare SOD1 mutations, with only one previous autopsy report, and is known for its longer disease duration. As previously reported, the patient had weakness in the lower limbs at age 33, followed by dysphagia, dysesthesia in the lower limbs, and autonomic dysfunction. He required mechanical ventilation at age 44 and died of acute pancreatitis at age 70. Neuropathologically, multisystem degeneration was observed beyond lesions typical of familial ALS with posterior column involvement. In addition, there was no SOD1-positive inclusion in the remaining motor neurons. The absence of SOD1-positive inclusion is a rare feature observed predominantly in long survival cases with SOD1 gene mutations. We hypothesize that the considerably lower amount of abnormal SOD1 protein in the motor neuron cells might explain our patient's extraordinarily long clinical course.

ALK-positive histiocytosis is a rare histiocytic disease characterized by ALK positivity. It was first described in 2008 as a systemic disease in infants. The disease often shows positivity for CD68 and CD163 on immunohistochemistry, and genomic analysis frequently reveals KIF5B::ALK fusions. ALK-positive histiocytosis typically follows an indolent course and has a promising prognosis, with conventional treatments usually being effective. Here, we report a rare case of ALK-positive histiocytosis with exclusive involvement of the central nervous system in a 33-year-old Asian adult woman. Although cranial MRI suggested a meningioma, immunohistochemical workup showed that the ALK-positive tumor cells expressed macrophage/histiocyte markers such as CD163 and CD68. Additionally, second-generation sequencing revealed a KIF5B::ALK fusion. Our case highlights the importance of the differential diagnosis in adult central nervous system tumors, emphasizing the combination of morphology, immunophenotype, and molecular approach with ALK status evaluation to confirm a diagnosis of ALK-positive histiocytosis. This case also expands the clinicopathologic spectrum of ALK-positive histiocytosis.

The aim of this paper is to analyze the pathophysiological mechanisms acting in very early classic Guillain-Barré syndrome (GBS) (≤4 days of symptomatic onset). In this inaugural period, both in GBS and its animal model, experimental autoimmune neuritis, the outstanding pathological feature is inflammatory edema predominating in proximal nerve trunks, particularly spinal nerves, and possibly in preterminal nerve segments. Nerve trunks external to the subarachnoid angle possess epi- perineurium that is relatively inelastic and of low compliance. Here such edema can increase endoneurial fluid pressure that, when sufficiently critical, may stretch the perineurium and constrict transperineurial microcirculation, compromising blood flow and producing the potential for ischemic nerve injury, whose consequence is rapid partial or complete loss of nerve excitability. These histopathological features correlate well with electrophysiological and imaging findings reported in early GBS stages. Spinal nerve edema and ischemia help to understand the pattern of Wallerian-like degeneration observed in the axonal form of GBS, predominating in motor spinal roots at their exit from the dura matter (spinal nerves) with centrifugal distribution in more distant motor nerve trunks, and centripetal extension to the distal portion of intrathecal roots. The similarity of initial pathogenic mechanisms between demyelinating and axonal forms of GBS explains why an early increase of serum biomarkers of axonal damage is detected in both forms. In conclusion, knowledge of the microscopic anatomy of the peripheral nervous system is an essential step for a reliable understanding of pathophysiological mechanisms operating in the early phase of any classic GBS subtype.

A 55-year-old Japanese woman with a history of hypertension and right putaminal hemorrhage developed simultaneous hemorrhages in the left thalamus and putamen and died 24 h later. There were no vascular anomalies in the brain. Synaptophysin immunostaining combined with eosin azure 50 (EA50) staining clearly identified the hematoma and the surrounding brain structures. In the right cerebral hemisphere, a cystic lesion as a sequela of the usual type of hypertensive putaminal hematoma was evident. In the left cerebral hemisphere, two fresh hematomas were evident. One was a thalamic hematoma, which had destroyed the dorsal and medial structures of the thalamus, and the other was an unusual putaminal hematoma, which had destroyed the entire putamen and crossed the internal capsule and caudate nucleus. α-Smooth muscle actin immunostaining combined with EA50 and Victoria bleu staining demonstrated three ruptured arteries associated with fibrin aggregates in the anterior thalamic nucleus and anterior putamen. Some circular structures composed of fibrin, suggesting the presence of ruptured arteries in the neighborhood, were evident in the thalamus and putamen. In the putamen, ruptured arteries and circular structures were present in the lateral to medial areas. Fibrin aggregates in the anterior thalamic nucleus were more numerous than those in the putamen. On the basis of these findings, we concluded that: (i) the artery with numerous fibrin aggregates in the anterior thalamic nucleus had ruptured first, followed by the arteries distributed in other parts of the thalamus and putamen; (ii) the unusual putaminal hematoma was attributable to rupture of the arteries around the center of the putamen, which are not responsible for the usual type of hypertensive putaminal hematoma; and (iii) it is suggested that even if hypertensive hemorrhage occurs simultaneously in the ipsilateral putamen and thalamus, the usual type of hypertensive mixed-type hematoma does not form.

Eosinophilic angiocentric fibrosis (EAF) is a rare, benign fibroinflammatory condition primarily affecting the sinonasal and upper respiratory tract, with a few cases reported beyond these regions. Primary intracranial EAF is rare. To date, only one case of intracranial EAF has been reported; ours is the second. This case report presents a case of EAF in a 55-year-old man, initially misdiagnosed as meningioma based on clinical and radiological features. The patient complained of a persistent dull headache for six months without associated neurological symptoms. Brain magnetic resonance imaging revealed a dural-based lesion with characteristics suggestive of meningioma. However, histopathological examination post-surgical resection revealed a nodular vascular lesion with concentric angiocentric fibrosis, a distinctive onion skin pattern, and an inflammatory infiltrate rich in eosinophils, plasma cells, and histiocytes. Immunohistochemistry ruled out IgG4-related disease, and other systemic disorders were ruled out based on combined clinical and histological features. This case underscores the need for considering EAF in the differential diagnosis of dural-based lesions. Awareness of its potential mimicking of meningioma is crucial for accurate diagnosis and appropriate management, emphasizing the importance of histopathological examination in challenging cases.

N-myc downstream regulated gene 1 (NDRG1) is a member of the NDRG family, of which four members (NDRG1, NDRG2, NDRG3, and NDRG4) have been identified. NDRG1 is repressed by c-MYC and N-MYC proto-oncogenes. NDRG1 is translated into a 43 kDa protein that is associated with the regulation of cellular stress responses, proliferation, and differentiation. In this study, we aimed to clarify the relationship between progression of glioblastoma (GB) IDH-wildtype and NDRG1 expression in tumor cells. We assessed the expression of NDRG1 in 41 GBs using immunostaining and evaluated its prognostic significance. NDRG1 expression by GBs was evaluated using Histoscore, which showed high and low scores in 23 and 18 cases, respectively. NDRG1-positive cells were strongly expressed in Ki-67 labeled proliferating tumor cells and CD105 positive proliferating microvessels around the area of palisading necrosis. Statistical analyses showed lower survival rates in the high-score group than the low-score group (P < 0.01). This study indicated that overexpression of NDRG1 by GB reflects tumor angiogenesis and poor patient prognosis.

We report an autopsy case of a 70-year-old man who was clinically diagnosed with atypical progressive supranuclear palsy (PSP). He initially presented with gait ataxia and then showed vertical gaze palsy, rigidity, akinesia, dysphagia, and mild cognitive impairment, followed by prominent upper motor signs later in the course of the disease. Cranial magnetic resonance imaging revealed tegmental atrophy of the midbrain. Autopsy revealed severe neuronal loss and gliosis in the motor cortex and corticospinal degeneration and mild to moderate neuronal loss and gliosis in the basal ganglia, substantia nigra, midbrain, and pons. Tufted astrocytes were primarily found in the motor cortex and basal ganglia. Globose-type neurofibrillary tangles were observed in the locus coeruleus and nucleus olivaris inferior. In the cerebellar cortex, mild Purkinje cell loss and scattered axonal torpedoes were observed with tau-positive Purkinje cells. The dentate nucleus displayed severe neuronal loss and gliosis. The present case showed characteristics of both PSP with prominent cerebellar ataxia (PSP-C) and PSP-primary lateral sclerosis (PSP-PLS).

Dystrophinopathy is caused by alterations in the dystrophin gene. The severe phenotype, Duchenne muscular dystrophy (DMD), is caused by a lack of dystrophin in skeletal muscles, resulting in necrosis and regenerating fibers, inflammatory cells, and muscle fibrosis. Progressive muscle weakness is a characteristic finding of this condition. Here, we encountered a rare case of a 10-year-old patient with asymptomatic dystrophinopathy with no dystrophin expression and investigated the reason for the absence of muscle weakness to obtain therapeutic insights for DMD. Using RNA-seq analysis, gene expression in skeletal muscles was compared among patients with asymptomatic dystrophinopathy, three patients with typical DMD, and two patients without dystrophinopathy who were leading normal daily lives. Cathepsin K (CTSK), myosin heavy chain 3 (MYH3), and nodal modulator 3-like genes exhibited a >8-fold change, whereas crystallin mu gene (CRYM) showed a <1/8-fold change in patients with typical DMD compared with their expression in the patient with asymptomatic dystrophinopathy. Additionally, CTSK and MYH3 expression exhibited a >16-fold change (P < 0.01), whereas CRYM expression showed a <1/16-fold change (P < 0.01) in patients with typical DMD compared with their expression in those without dystrophinopathy. CTSK plays an essential role in skeletal muscle loss, fibrosis, and inflammation in response to muscles injected with cardiotoxin, one of the most common reagents that induce muscle injury. Increased CTSK expression is associated with muscle injury or necrosis in patients with DMD. The lack of muscle weakness in the patient with asymptomatic dystrophinopathy might be attributed to the low CTSK expression in the muscles. To the best of our knowledge, this is the first report to demonstrate that CTSK expression was significantly higher in the skeletal muscles of patients with DMD with a typical phenotype than in those without dystrophinopathy.

The 2021 World Health Organization (WHO) classification of the central nervous system (CNS) tumors has classified diffuse leptomeningeal glioneuronal tumor (DLGNT) as a mixed neuronal and glial tumor. Here, we report a DLGNT with two distinct morphological tumor components but identical molecular features. A four-year-old female child presented with progressive right upper extremity weakness. Magnetic resonance imaging (MRI) revealed the leptomeningeal enhancement over the brain stem and cervicothoracic spine. The histological examination of surgical specimens revealed two distinct tumor components: approximately half of the tumor is composed of oligodendroglioma-like tumor intermingled with nodules of ganglioglioma-like tumor. Immunohistochemistry confirmed the oligodendroglioma and ganglioglioma features. The molecular genetic studies demonstrated the features of DLGNT, including fusion of KIAA1549::BRAF, deletion of chromosome 1p, and absence of isocitrate dehydrogenase 1/2 (IDH1/2) mutation in both tumor components. Interestingly, the genetic studies also revealed the distinct chromosomal abnormalities of the loss of chromosome 4 only in oligodendroglioma-like tumor and copy neutral loss of heterozygosity of 7Q34Q36.3 in the ganglioglioma-like tumor component. This case highlights the critical role of molecular testing in the diagnosis of rare cases of DLGNT with diverse morphological components as well as in the identification of unique molecular alternations responsible for morphological phenotypes of the distinct tumors in DLGNT.