Neuropathology最新文献

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.

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.

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.

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.

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.

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.

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.

Since the World Health Organization (WHO) 2016 revision, the number of molecular markers required for diffuse gliomas has increased, placing a burden on clinical practice. We have established an in-house, molecular diagnostic platform using Senshin-Iryo, a feature of Japan's unique healthcare system, and partially modified the analysis method in accordance with the WHO 2021 revision. Herein, we review over a total 5 years of achievements using this platform. Analyses of IDH, BRAF, and H3 point mutations, loss of heterozygosity (LOH) on 1p/19q and chromosomes 10 and 17, and MGMT methylation were combined into a set that was submitted to Senshin-Iryo as "Drug resistance gene testing for anticancer chemotherapy" and was approved in August 2018. Subsequently, in October 2021, Sanger sequencing for the TERT promoter mutation was added to the set, and LOH analysis was replaced with multiplex ligation-dependent probe amplification (MLPA) to analyze 1p/19q codeletion and newly required genetic markers, such as EGFR, PTEN, and CDKN2A from WHO 2021. Among the over 200 cases included, 54 were analyzed after the WHO 2021 revision. The laboratory has maintained a diagnostic platform where molecular diagnoses are confirmed within 2 weeks. Initial expenditures exceeded the income from patient copayments; however, it has gradually been reduced to running costs alone and is approaching profitability. After the WHO 2021 revision, diagnoses were confirmed using molecular markers obtained from Senshin-Iryo in 38 of 54 cases (70.1%). Among the remaining 16 patients, only four (7.4%) were diagnosed with diffuse glioma, not elsewhere classified, which was excluded in 12 cases where glioblastoma was confirmed by histopathological diagnosis. Our Senshin-Iryo trial functioned as a salvage system to overcome the transition period between continued revisions of WHO classification that has caused a clinical dilemma in the Japanese healthcare system.

Argyrophilic grain disease (AGD) is one of the major pathological backgrounds of senile dementia. Dementia with grains refers to cases of dementia for which AGD is the sole background pathology responsible for dementia. Recent studies have suggested an association between dementia with grains and parkinsonism. In this study, we aimed to present two autopsy cases of dementia with grains. Case 1 was an 85-year-old man who exhibited amnestic dementia and parkinsonism, including postural instability, upward gaze palsy, and neck and trunk rigidity. The patient was clinically diagnosed with progressive supranuclear palsy and Alzheimer's disease. Case 2 was a 90-year-old man with pure amnestic dementia, clinically diagnosed as Alzheimer's disease. Recently, we used cryo-electron microscopy to confirm that the tau accumulated in both cases had the same three-dimensional structure. In this study, we compared the detailed clinical picture and neuropathological findings using classical staining and immunostaining methods. Both cases exhibited argyrophilic grains and tau-immunoreactive structures in the brainstem and basal ganglia, especially in the nigrostriatal and limbic systems. However, Case 1 had more tau immunoreactive structures. Considering the absence of other disease-specific structures such as tufted astrocytes, astrocytic plaques and globular glial inclusions, lack of conspicuous cerebrovascular disease, and no history of medications that could cause parkinsonism, our findings suggest an association between AGD in the nigrostriatal system and parkinsonism.