Nicolás Rincón-Arias

Background/Objectives: The 2021 World Health Organization Classification of Tumors of the Central Nervous System (WHO CNS5) integrates histological and molecular criteria for adult diffuse gliomas, but comprehensive molecular testing may be difficult to implement in resource-limited settings. This study assessed the feasibility of a sequential, marker-based approach for diagnostic reassessment and described its association with clinical characteristics and overall survival (OS) in adults from Colombia. Methods: We retrospectively analyzed 68 adults with diffuse gliomas treated at two referral hospitals in Bogotá, Colombia, between 2015 and 2023. Molecular assessment used IHC, FISH, PCR, and Sanger sequencing according to the available tissue and diagnostic workflow. The study did not include comprehensive NGS or systematic assessment of combined whole-chromosome 7 gain/chromosome 10 loss (+7/−10). Results: The diagnosis changed after molecular reassessment in 51.5% of cases. The proportion classified as glioblastoma increased from 48.5% under the historical histologic classification to 66.2% under the WHO CNS5-based algorithm, whereas FISH-defined oligodendrogliomas decreased from 17.6% to 11.8%. OS differed among historical histologic groups (p = 0.03), but not among the WHO CNS5-based groups (p = 0.13). Female sex was associated with longer OS in unadjusted analysis (p = 0.02), while age was the only independent predictor in the multivariable analysis. Conclusions: Sequential molecular reassessment materially changed diagnostic categorization in this cohort and was feasible using locally available marker-based methods. However, the results are exploratory, limited by small molecular subgroups, incomplete molecular coverage, and the retrospective treatment context; they should not be interpreted as demonstrating improved treatment selection or survival after reclassification.

Background/Objectives: The reclassification of gliomas in the 5th edition of the World Health Organization’s Classification of Tumors of the Central Nervous System (WHOCNS5) integrates histological and molecular criteria to improve diagnostic accuracy and enable an individualized treatment approach. This study aims to analyze the feasibility of WHOCNS5 reclassification by examining its impact on diagnostic distribution, clinical features, and overall survival (OS) in adult patients from Colombia. Methods: We retrospectively analyzed 68 adults with diffuse gliomas (2015–2023) from two referral hospitals in Bogotá, Colombia. Molecular testing for IDH, 1p/19q, ATRX, TP53, EGFR, TERT, and CDKN2A/B enabled tumor reclassification according to WHOCNS5. Clinical, radiographic, and survival data were statistically analyzed. Results: 58.8% of patients were male, with a mean age of 56.6 ± 15.5 years. A total of 51.5% of the cases varied in the diagnosis after molecular reclassification. WHOCNS5 identified 66.2% glioblastomas vs 48.5% according to WHOCNS3, and 11.8% oligodendrogliomas vs 17.6 according to WHOCNS3. Using the WHOCNS3 criteria, OS differed significantly among tumor subtypes (p = 0.03), while reclassification under WHOCNS5 reduced these differences (p = 0.13), although IDH-mutant astrocytomas and oligodendrogliomas showed a survival advantage. In all subtypes, a younger age and gender predicted better OS (p < 0.001 and p = 0.02, respectively). Conclusions: Implementing the WHOCNS5 reclassification substantially altered glioma categorization and refined prognostic interpretation in over half of the cases. Trends toward improved outcomes in IDH-mutant tumors persist after reclassification.

Background Subependymal giant cell astrocytoma (SEGA) is a rare pediatric tumor that most commonly occurs in the setting of tuberous sclerosis complex (TSC). The deep anatomical location of these lesions makes the selection of an appropriate neurosurgical approach critical. However, minimally invasive techniques have emerged as a safe and effective alternative for the surgical resection of tumors located in deep regions. Observations A 7-year-old male with a history of TSC presented with a large intraventricular mass located in the frontal horn of the right lateral ventricle, associated with symptoms suggestive of intracranial hypertension. A minimally invasive transcortical approach using a tubular retractor was initially performed, achieving a partial resection of the tumor, then followed by adjuvant targeted therapy and radiotherapy. Due to persistent seizures, the patient underwent a second intervention using a similar transcortical approach and tubular retraction, this time aided by neuronavigation. An estimated extent of resection (EOR) of 90–95% was achieved resulting in improvement of the patient’s neurological involvement. Lessons The integration of minimally invasive tubular retractor systems with neuronavigation represents an effective and safe strategy for the surgical management of SEGAs located in critical intraventricular regions. In this case, neuronavigation was essential in achieving GTR while minimizing intraoperative bleeding and reducing injury to critical cortical and subcortical structures. Minimally invasive approaches proved to be safe and were associated with a favorable postoperative course.

Background and Objective: The discovery of novel molecular biomarkers via next-generation sequencing technologies has revolutionized how glioblastomas (GBMs) are classified nowadays. This has resulted in more precise diagnostic, prognostic, and therapeutic approaches to address this malignancy. The present work examines the applications of single-cell RNA sequencing (scRNA-seq) in GBM, focusing on its potential to address tumor complexity and therapeutic resistance and improve patient outcomes. Methods: A scoping review of original studies published between 2009 and 2024 was conducted using the PUBMED and EMBASE databases. Studies in English or Spanish related to single-cell analysis and GBM were included. Key Findings: The database search yielded 453 publications. Themes related to scRNA-seq applied for the diagnosis, prognosis, treatment, and understanding of the cancer biology of GBM were used as criteria for article selection. Of the 24 studies that were included in the review, 11 focused on the tumor microenvironment and cell subpopulations in GBM samples, 5 investigated the use of sequencing to elucidate the GBM cancer biology, 3 examined disease prognosis using sequencing models, 3 applied translational research through scRNA-seq, and 2 addressed treatment-related problems in GBM elucidated by scRNA-seq. Conclusions: This scoping review explored the various clinical applications of scRNA-seq technologies in approaching GBM. The findings highlight the utility of this technology in unraveling the complex cellular and immune landscapes of GBM, paving the way for improved diagnosis and personalized treatments. This cutting-edge approach might strengthen treatment strategies against tumor progression and recurrence, setting the stage for multi-targeted interventions that could significantly improve outcomes for patients with aggressive, treatment-resistant GBMs.

Gamboa-Oñate CA, et al. Korean J Neurotrauma. 2024 Oct;20:e36. https://doi.org/10.13004/kjnt.2024.20.e36