Clinical Neuropathology最新文献

Molecular characterization has become a key diagnostic tool for the classification and grading of primary brain tumors. Molecular markers, such as isocitrate dehydrogenase (IDH) mutation status, 1p/19q codeletion, methylation of the O(6)-methylguanine-DNA methyltransferase (MGMT) promoter, or CDKN2A/B homozygous deletion discriminate different tumor entities and grades, and play a crucial role for treatment response and prognosis. In recent years, magnetic resonance imaging (MRI), whose main functions has been to detect a tumor, to provide spatial information for neurosurgical and radiotherapy planning, and to monitor treatment response, has shown potential in assessing molecular features of gliomas from image-based biomarkers. As an outstanding example, numerous studies have proven that the T2/FLAIR mismatch sign can identify IDH-mutant, 1p/19q non-codeleted astrocytomas with a specificity of up to 100%. For other purposes, multiparametric MRI, often coupled with machine learning methods, seems to achieve the highest accuracy in predicting molecular markers. Relevant future applications might be anticipating changes in the molecular composition of gliomas and providing useful information about the cellular and genetic heterogeneity of gliomas, especially in the non-resected tumor parts.

Brain metastases are the most common central nervous system malignancy, and the leading cause of cancer-related deaths. Non-small cell lung carcinomas (NSCLC) comprise the most common cell of origin. Immunotherapy, particularly checkpoint inhibitors, has emerged as the standard of care for many patients with advanced lung cancer. Pannexin1 (PANX1) is a transmembrane glycoprotein that forms large-pore channels and has been reported to promote cancer metastasis. However, the roles of PANX1 in lung cancer brain metastases and tumor immune microenvironment have not been characterized. 42 patient-matched formalin-fixed paraffin-embedded tissue samples from lung carcinomas and the subsequent brain metastases were constructed into three tissue microarrays (TMAs). PANX1 and markers of tumor-infiltrating immune cells (CD3, CD4, CD8, CD68, and TMEM119) were assessed using immunohistochemistry and digital image analysis. The expression of PANX1 was significantly higher in brain metastases than in their paired primary lung carcinoma. The high levels of PANX1 in lung carcinoma cells in the brain inversely correlated with infiltration of peripheral blood-derived macrophages. Our findings highlight the role of PANX1 in the progression of metastatic NSCLC, and the potential therapeutic approach of targeting PANX1 enhances the efficacy of immune checkpoint inhibitors in brain metastasis.

There are no international guidelines for brain biopsy in neurological disease of unknown etiology, yet most practicing neurologists will encounter difficult cases in which biopsy is considered. This patient cohort is heterogenous, and it is unclear in which circumstances biopsy is most useful. We performed an audit of brain biopsies reviewed in our neuropathology department from 2010 to 2021. Of 9,488 biopsies, 331 biopsies undertaken for an undiagnosed neurological disease were identified. Where documented, the commonest symptoms were hemorrhage, encephalopathy, and dementia. 29% of biopsies were non-diagnostic. The most common clinically relevant findings on biopsy were infection, cerebral amyloid angiopathy with or without angiitis, and demyelination. Rarer conditions included CNS vasculitis, non-infectious encephalitis, and Creutzfeldt Jakob Disease. We highlight the value of brain biopsy in the workup of cryptogenic neurological disease despite recent advances in less invasive diagnostics.

Delineation of the autoimmune encephalitides with antibodies against neural surface antigens (anti-N-Methyl-D-aspartate, anti-leucine-rich glioma-inactivated protein 1, and others), autoimmune-associated epilepsies (Rasmussen encephalitis, paraneoplastic encephalitides, temporal lobe epilepsy with antibodies against glutamic acid decarboxylase), and encephalomyelitides with glial antibodies (neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody disease) has been a major advance in neurology. But how do these inflammatory diseases "work"? What kind of interaction between elements of the immune system and brain cells leads to these conditions? The only direct way of answering these questions is to investigate affected brain tissue by neuropathological techniques. They provide morphological and, in part, temporal information on the elements and localization of the disease process. Molecular techniques broaden and support these data. Brain tissue becomes available through autopsies and brain biopsies, obtained for diagnostic or therapeutic interventions. The limitations of neuropathological pathogenic research are discussed. Finally, representative neuropathological findings in autoimmune encephalitides and related conditions are summarized.

We previously reported on the first neuropathological round robin trials operated together with Quality in Pathology (QuIP) GmbH in 2018 and 2019 in Germany, i.e., the trials on IDH mutational testing and MGMT promoter methylation analysis [1]. For 2020 and 2021, the spectrum of round robin trials has been expanded to cover the most commonly used assays in neuropathological institutions. In addition to IDH mutation and MGMT promoter methylation testing, there is a long tradition for 1p/19q codeletion testing relevant in the context of the diagnosis of oligodendroglioma. With the 5^th edition of the World Health Organization (WHO) classification of the central nervous system tumors, additional molecular markers came into focus: TERT promoter mutation is often assessed as a molecular diagnostic criterion for IDH-wildtype glioblastoma. Moreover, several molecular diagnostic markers have been introduced for pediatric brain tumors. Here, trials on KIAA1549::BRAF fusions (common in pilocytic astrocytomas) and H3-3A mutations (in diffuse midline gliomas, H3-K27-altered and diffuse hemispheric gliomas, H3-G34-mutant) were most desired by the neuropathological community. In this update, we report on these novel round robin trials. In summary, success rates in all four trials ranged from 75 to 96%, arguing for an overall high quality level in the field of molecular neuropathological diagnostics.

Background: Inflammatory myofibroblastic tumors (IMTs) are a distinct entity of mesenchymal tumors. We present the challenges in their diagnosis and management.

Materials and methods: A retrospective study with detailed clinical, radiological, and histopathological (HPE) features along with management and outcome of 10 biopsy-proven patients with IMT, between 2001 and 2020.

Results: The location included intracranial (5), orbital (4), and spinal (1) with M : F = 7 : 3. The mean age of onset was in the third decade. The commonest symptom was headache, while proptosis and blurred vision occurred in orbital IMTs. HPE revealed diffuse infiltration of mixed inflammatory cells over proliferating myofibroblasts. Smooth muscle antigen immunoreactivity was noted in fibroblastic spindle cells of all IMTs. However, we did not find anaplastic lymphoma kinase expression in any of our cases, as this is only found in ~ 50% of all IMTs. Tumor infiltration into adjacent tissue was noted in 4 patients. Surgical excision was limited to orbital IMTs, as most central nervous system (CNS) tumors were not amenable for resection. Steroid administration showed moderate improvement in the IMT-CNS patients but also required additional immunomodulation. Four patients had a median long-term follow-up of 7 years. Two patients had recurrent lesions demonstrated by imaging after 2 years of initial presentation.

Conclusion: IMTs are rare and ambiguous tumors of unknown etiology that can occur anywhere in the body. Clinical and radiological features may not be specific to determine the diagnosis, but it should be considered as a differential diagnosis. Extensive thorough workup with histopathology along with the help of immunohistochemistry is conducive to better clinical outcomes. Surgical biopsy with extensive and total resection of these tumors along with steroid and radiotherapy may enhance the survival outcomes.

Aims: Central nervous system (CNS) and spine are seldom impacted by primary or metastatic sarcomas. We reviewed our 22-year experience with metastatic versus primary mesenchymal sarcomas in adults versus pediatric patients, additionally asking how many might today undergo nomenclature changes using CNS World Health Organization, 5^th edition criteria.

Materials and methods: Case identification via text word search of pathology databases from our adult and pediatric referral hospitals, 2000 to August 2022, with exclusion of peripheral nervous system and primary chondro-osseous and notochordal tumors. Demographic, immunohistochemical, fluorescence in situ hybridization (FISH), and fusion results performed at the time of original diagnosis were acquired from reports.

Results: 57 cases were identified, with a 16 : 15 primary and 19 : 7 metastatic ratio in adult versus pediatric patients. Ewing sarcoma was the most frequent type (n = 18, 7 adult, 11 pediatric), with a rare primary PEComa, 2 alveolar soft part sarcomas, and metastatic angiosarcoma in the cohort. Only 3 cases, an intracranial sarcoma, DICER-1 mutant formerly diagnosed as rhabdomyosarcoma, an intracranial mesenchymal tumor, FET::CREB fusion-positive formerly diagnosed as angiomatoid fibrous histiocytoma, and a CIC-rearranged sarcoma required nomenclature updating by CNS WHO5 criteria.

Conclusions: Few primary or metastatic, adult or pediatric, CNS/spinal sarcomas required nomenclature updates; almost all had been satisfactorily classified at the time of diagnosis, using immunohistochemistry, FISH, or fusion results.