Clinical Neuropathology最新文献

Cerebellar liponeurocytoma (CL) is a rare WHO grade 2 tumor characterized by advanced neuronal differentiation and variable lipomatous features. Initially classified as a subtype of medulloblastoma, CL was later considered as a distinct entity owing to its peculiar morphological and molecular features and significant better outcome. Typically affecting adults, CL often presents with symptoms related to cerebellar dysfunction, including headaches, ataxia, and gait disturbances. On magnetic resonance imaging, this tumor presents as a well-defined, heterogeneous mass with lipomatous components, which may be less or more apparent depending on their extent. Histologically, CL is composed of neurocytic cells and lipidized tumor cells; the immunohistochemical positivity for synaptophysin and NeuN confirms the neuronal differentiation of neoplastic cells. In spite of its morphological similarity to medulloblastoma, CL lacks the genetic alterations commonly found in this tumor, but some cases display TP53 mutations. Complete surgical resection is the gold standard treatment, whereas the benefit of adjuvant radiotherapy is controversial. CL generally harbors a favorable prognosis, with low recurrence rates in cases with incomplete resection or high proliferative index. The present paper comprehensively reviews the literature about CL, emphasizing the clinicopathologic and molecular features of this unusual but distinct neuropathological entity.

Chromoblastomycosis in intracranial locations is extremely rare in immunocompetent hosts. Neurotropism of fungal elements has been reported in the literature mostly in immunocompromised individuals. We report a case of a 36-year-old industrial worker with disseminated untreated skin lesions and presenting with cerebellar symptoms and space-occupying lesion in the left cerebellar hemisphere. Histopathological examination revealed a diagnosis of cerebellar chromoblastomycosis. To our knowledge, this is the first reported case of cerebellar chromoblastomycosis in an immunocompetent individual.

Introduction: Thalidomide has shown exceptional results in the management of Behçet's disease. Despite its efficacy, thalidomide is associated with a number of adverse effects, including peripheral neuropathy. This study aims to characterize the pathologic features of neuropathy in Behçet's disease patients who received thalidomide therapy.

Materials and methods: Consecutive adult Behçet's disease patients who received thalidomide and developed neuropathy were collected. Clinical manifestations, electrophysiologic evaluations, and pathologic findings were studied.

Results: Three patients who met the inclusion criteria were collected. Sensory deficits, particularly in the lower extremities, emerged in a length-dependent manner 6 - 12 months after initiation of thalidomide therapy. Symptoms remained unchanged after discontinuation of thalidomide for 2 years. Electrophysiologic evaluations showed sensory axonal polyneuropathy in all 3 patients who also received sural nerve biopsy. Histological findings confirmed axonal degenerations. A noteworthy finding was neurofilament accumulation in both myelinated and unmyelinated axons.

Discussion: Sensory fibers, particularly in the lower extremities, were susceptible to thalidomide therapy. The features of thalidomide-induced neuropathy are characterized as axonal degeneration.

Conclusion: Earlier recognition of thalidomide-induced sensory axonal neuropathy should be carried out in patients with Behçet's disease during the thalidomide therapy.

Background: Symptomatic sellar salivary gland-like lesions (SSGLs) are uncommon, with fewer than two dozen case reports. Prior case reports have also not detailed pre- or postoperative endocrinopathies to determine if these lesions can be clinically distinguished prior to biopsy from Rathke cleft cysts (RCCs). In addition, prior molecular testing was attempted to provide further insights as to whether these might be developmental lesions or true neoplasms, but testing was unsuccessful.

Materials and methods: Report of 2 new cases of SSGLs with molecular testing to assess for potential gene mutations, copy number alterations, and fusions with literature review detailing demographic, clinical, endocrinological, neuroimaging, histological, and outcome features.

Results: A 53-year-old female and 33-year-old male developed large sellar lesions. The woman presented with fatigue and sudden-onset visual changes and the man with apoplectic-like severe headache. Biopsy specimens for both patients demonstrated clusters of histologically benign salivary gland-like acini accompanied by varying amounts of mucin and lymphocytic inflammation. None showed pituitary tumor. Postoperatively, one case developed persistent diabetes insipidus. Molecular testing revealed a lack of pathogenic mutations, copy number alterations, or gene fusions in both cases.

Conclusion: SGGLs differ histologically and sometimes in size from RCCs, although both can be cystic, contain abundant mucin, and may result in postoperative transient or permanent diabetes insipidus; they cannot be completely distinguished preoperatively from RCCs. Molecular testing did not demonstrate any mutations, copy number changes, or fusions for either case. Lack of pathogenic genetic alterations suggest these lesions may not be true neoplasms.

A 21-year-old woman presented with progressive proptosis of the right eye with blurring of vision for the past 6 months. MRI showed an intra-orbital lesion that was T1 isointense, T2 hyperintense, and well enhancing on contrast. The patient underwent right frontal craniotomy, superior orbitotomy, and decompression of the lesion. Histopathology showed a glomus tumor with increased mitotic figures, consistent with a glomus tumor of uncertain malignant potential (GT-UMP). GT-UMP has an aggressive behavior that requires the need for adjuvant therapy following surgical excision. BRAF V600E mutation in these cases opens a new avenue for targeted therapy and precision medicine. This is the second reported case of a GT-UMP involving the orbit, and we have demonstrated BRAF V600E mutation in this case, which recurred in a short span, reiterating the aggressive nature of the tumor and the necessity of targeted therapy.

Aims: Expression patterns of key proteins involved in RAS signaling and connected pathways were determined and correlated to possibly provide information for therapeutic application of RAS inhibitors in neurofibromatosis type 1 (NF1)-associated peripheral nerve sheath tumors (PNST).

Materials and methods: Clinical variables (age, sex), histological parameters (cell density, mitoses), and expression of immunohistochemically evaluated ligand and receptor proteins (neuregulin 1 (NRG1), ErbB2, ErbB3), RAS pathway proteins (mTor, Rho, phosphorylated MEK), transcription factors (Pax7, Sox9), and proliferation marker Ki-67, were correlated in cutaneous (CNF, n = 136), diffuse (DNF, n = 123)/diffuse plexiform (DPNF, n = 113), and plexiform neurofibroma (PNF, n = 126), and in malignant PNST (MPNST, n = 22).

Results: In CNF, NRG1 correlated with Ki-67 and Pax7. Further, mTOR correlated with ErbB3, Sox9, Pax7, and Ki-67. In DNF/DPNF, expression of NRG1 correlated with pMEK and Pax7. mTOR correlated with pMEK, Sox9, and Pax7. Noteworthy, pMEK was weakly expressed in some DNF but not in DPNF. ErbB3 correlated with mTor and Ki-67. Furthermore, Rho correlated with Pax7 and Ki-67. In PNF, ErbB3 expression was associated with Sox9, mTOR, pMEK, and Pax7 as well as mTOR with Sox9 and Pax7, Rho with pMEK and Pax7, and pMEK with Pax7 and Sox9. In MPNST, only few correlations were observed, ErbB2 correlated with Ki-67, and Rho with pMEK.

Conclusion: Signaling networks of the RAS pathway could be retraced by correlation analysis of protein expression in subgroups of NF1 associated benign PNST. In regard to treatment of PNST, MEK inhibitors, which are presently evaluated for PNF, may possibly also be effective to some extent in DNF.

Glioma is the most common brain tumor, accounting for a large majority of cancer-related deaths. β-galactoside α2, 6 sialyltranferase 1 (ST6Gal1), the primary enzyme responsible for the conjugation of α2, 6 sialic acids to protein and lipid targets, is strongly associated with the occurrence and development of several brain tumor types. Still, the expression, targets, and functions of ST6Gal1 in glioma patients remain undetermined. As sialylation of the Ig-like cell adhesion family molecules have prominent roles in the latter's regulation in other biological contexts, we screened for members that have potential to be regulated by ST6Gal1 in silico and examined co-expressed protein modules using data derived from the Cancer Genome Atlas (TCGA) database, and we identified neural cell adhesion molecule (NCAM1) as a major ST6Gal1-interacting target. Bioinformatic binding analysis confirmed the interaction of ST6Gal1 and NCAM1. Immunohistochemistry was then used to evaluate post-operative samples from 156 patients with gliomas. ST6Gal1 and NCAM1 were co-expressed in gliomas, and their expression correlated significantly (p = 0.002) by univariate analysis. Our study also found that the expression levels of both ST6Gal1 and NCAM1 corresponded negatively with glioma grade, isocitrate dehydrogenase (IDH) mutation, and proliferation index (Ki67). Consistently, Kaplan-Meier survival curves showed that lower ST6Gal1 and NCAM1 protein levels are linked to unfavorable outcomes in glioma patients (p = 0.018 and p < 0.001, respectively). Our data indicate that ST6Gal1 may participate in the inhibition of oncogenesis and malignant progression via interacting with and targeting NCAM1 in glioma, thus presenting a novel strategy for intervention.

Granule cell neuronopathy (GCN) caused by John Cunningham virus (JCV) is a rare yet significant neurological complication, particularly in immunocompromised individuals such as those with AIDS. We present a case of a 34-year-old HIV-positive male exhibiting classical symptoms of cerebellar dysfunction. Magnetic resonance imaging revealed demyelination suggestive of progressive multifocal leukoencephalopathy (PML). Histopathological examination confirmed JCV-GCN, characterized by lytic infection of cerebellar granule cell neurons. Among the 41 reported cases of JCV-GCN, histopathological data were available for only 10 cases. Ours is the 11^th case with available histopathology. This case underscores the importance of considering JCV infection in the differential diagnosis of progressive cerebellar syndromes in immunocompromised patients. Early recognition and diagnosis are crucial for appropriate management and prognosis.

Aims: Corticobasal degeneration (CBD) is a rare neurodegenerative disorder. The status of the inferior olivary nucleus (ION) in CBD has been inadequately investigated. In this study, we conducted a pathological investigation of the ION in CBD.

Materials and methods: We reviewed the data of Japanese patients with pathologically confirmed CBD who underwent consecutive autopsies between 1985 and 2020 at our institute. We retrospectively examined clinical data from medical records and clinicopathological conferences and semi-quantitatively assessed the ION, central tegmental tract, superior cerebellar peduncle, and dentate nucleus.

Results: Of the 32 patients included, 14 (43.8%) had hypertrophy of the ION (HION), of whom 6 showed laterality. In the 14 HION cases, with or without laterality, except in 1 unevaluable case, atrophy/myelin pallor of the central tegmental tract was observed on the same side as the hypertrophy. Ten patients with HION, with or without laterality, had atrophy/myelin pallor of the superior cerebellar peduncle on the contralateral side to the hypertrophy.

Conclusion: The ION presents with hypertrophic changes in CBD. The lesion is a primary degeneration in CBD and is related to the degeneration of the Guillain-Mollaret triangle. This finding contributes to the elucidation of the specific pathological characteristics of CBD.