Faculty Bibliography

BACKGROUND:Glioblastoma intramedullary spinal cord metastasis (GISCM) is a rare sequela of high-grade astrocytoma and glioblastoma multiforme (GBM). Discrete intramedullary spinal cord metastases are less common than spinal leptomeningeal spread and may follow a more indolent course. Once identified as GISCM, palliative maximal safe resection of the tumor may be considered to alleviate neurological symptoms. Reports describing the surgical management of these rare lesions, including the use of emerging technologies that may aid in maximal safe resection, are sparse. A further understanding is also required regarding the course of disease and factors contributing to mortality in GISCM. METHODS:We reviewed the intraoperative management and clinical course of three patients treated for GISCM at our institution between 2015 and 2024. We additionally conducted a PRISMA-guided systematic literature review of PubMed Central, MEDLINE, and Bookshelf databases through May 26th, 2025, including original patient reports of GISCM from cranial astrocytoma or GBM. The disease course, management strategies, and causes of mortality in previously reported cases were analyzed. RESULTS:Our institutional cohort had a mean time to spinal metastasis of 26.2 months from diagnosis of cranial disease (range 17.5-40.5 months), with a mean survival of 9.2 months following maximal safe resection of extramedullary components (range 7-12 months). In two cases, intraoperative Stimulated Raman Histology (SRH) was employed to facilitate the rapid identification of metastatic GBM, thereby influencing surgical strategy. In one case, 5-aminolevulinic acid (5-ALA) was used to differentiate between tumor and spinal cord parenchyma, facilitating maximal safe debulking without neurological injury. Literature review identified 38 prior reported cases of GISCM, with a median time to spinal diagnosis of 11.0 months and a median survival of 3.5 months thereafter. The cause of death in the review cohort often involved multiple factors, and when analyzed for contributing factors to death, 38.7% involved cranial progression, 38.7% involved progression of spinal disease, and 29.0% involved medical complications. Gait ataxia at presentation was associated with shorter survival in review patients, potentially reflecting advanced disease with extramedullary cord compression. CONCLUSION/CONCLUSIONS:GISCM represents an entity distinct from leptomeningeal disease and may be managed in conjunction with recurrent cranial disease. Surgical debulking is a technically feasible strategy that can be safely facilitated using tools employed in the management of intracranial GBM, facilitating maximal safe resection without compromising survival.

BACKGROUND:While immune checkpoint inhibitors (ICI) induce potent responses against several systemic malignancies, clinical efficacy against high-grade glioma has been limited by immunosuppression, low mutational burden and limited lymphocyte infiltration into tumors. Laser interstitial thermal therapy (LITT) induces coagulative necrosis and disrupts the peritumoral blood-brain barrier (BBB), creating a potentially antigenic milieu. We hypothesized that neoadjuvant and adjuvant ICI would synergize with LITT to potentiate antitumor immune responses and enhance survival. METHODS:This retrospective study is an exploratory case series that includes 9 adult patients with recurrent IDH wild-type glioblastoma (GBM, n = 6), IDH mutant high-grade astrocytoma (n = 2) and H3K27M mutant diffuse midline glioma (n = 1). All patients received neoadjuvant anti-PD1 ICI prior to LITT and most received adjuvant ICI (8/9). Disease burden was followed through radiographic volume segmentation of gadolinium-enhancing disease. Patients were followed for progression-free (PFS) and overall survival (OS). RESULTS:). There were no perioperative complications. All patients showed an initial increase in gadolinium-enhancing volume after LITT. Seven of 9 (78 %) patients demonstrated subsequent regression in total gadolinium-enhancing volume. Three non-contiguous satellite lesions naïve to laser ablation exhibited complete or near-complete regression in 2 patients. Median PFS was 5.90 months (range 1.00-41.23), and median OS was 9.97 months (range 1.20-41.23). CONCLUSIONS:Combination therapy with neoadjuvant and adjuvant pembrolizumab and LITT is feasible and safe in recurrent high-grade glioma. Responses may be more robust in certain molecular subtypes of glioma. Further studies are needed to investigate this potential synergy.

Standard techniques for detecting genomic rearrangements in formalin-fixed paraffin-embedded (FFPE) biopsies have important limitations. We performed FFPE-compatible Hi-C on 44 clinical biopsies comprising large B cell lymphomas (n = 18), plasma cell neoplasms (n = 14), and other diverse lymphoid cancers, identifying consistent topological differences between malignant B cell and plasma cell states. Hi-C detected expected oncogene rearrangements at high concordance with fluorescence in situ hybridization (FISH) and supported enhancer hijacking in recurrent rearrangements of BCL2, CCND1, and MYC plus unanticipated variants involving homologous loci. Hi-C identified unanticipated non-coding rearrangements involving PD-1 ligand genes and other loci of potential therapeutic relevance, distinguished between functionally divergent classes of BCL6 rearrangements, and provided topological information supporting interpretation of variant MYC rearrangements. Hi-C revealed disease-selective MYC locus topological features that correlated with disease-selective MYC locus enhancers and rearrangement breakpoint distributions. FFPE-compatible Hi-C detects oncogene rearrangements and their topological consequences at genome-wide scale, finding clinically relevant drivers missed by standard approaches.

BACKGROUND:Meningiomas are the most common adult brain tumors. While homozygous deletions of CDKN2A/B are linked to early recurrence and hence serve as CNS WHO grade 3 criterion, the clinical impact of hemizygous deletions remains unclear-especially since distinguishing between hemi- and homozygous losses can be technically challenging. METHODS:DNA methylation data, copy-number and mutation data were evaluated on a multicenter cohort of 970 meningiomas. Each sample's CDKN2A/B status was manually classified by visual inspection in relation to whole chromosomal losses and gains in the copy number profile generated from global methylation array in relation to other copy number events. Progression probabilities were determined using the Kaplan-Meier method. RESULTS:Among 970 meningiomas, n = 30 had homozygous, n = 114 hemizygous (n = 31 segmental; n = 83 focal) and n = 826 CDKN2A/B balanced status. In cases with hemizygous deletions in general, an association with increased progression risk compared to balanced cases was observed, although this did not reach statistical significance (log-rank p = 0.074; HR 1.36, 95% CI [0.97, 1.90]; p = 0.07). However, segmental hemizygous losses were linked to a significantly worse prognosis (log-rank p = 0.0023), but focal hemizygous deletions were not (log-rank p = 0.523). Segmental hemizygous CDKN2A/B deletions were more frequently associated with a higher amount of high-risk copy number variations (CNVs) than focal losses. CONCLUSION/CONCLUSIONS:Our findings suggest that hemizygous CDKN2A/B deletions overall do not confer worse risks for progression in meningiomas. The signal for segmental deletions may not be locus-specific but just one representation of the generally instable genome of aggressive meningiomas.

The detection and identification of intracranial tumours is limited by the lack of accurate biomarkers and requires invasive biopsy procedures. We investigated a machine perception liquid biopsy approach to detect and identify intracranial tumours from peripheral blood and to discover biomarkers responsible for the predictions. Quantum well defect-modified single-walled carbon nanotubes stabilized with single-stranded DNA, interrogating 739 plasma samples from brain tumour patients, were used to train and validate machine-learning models to detect intracranial tumours with 98% accuracy and identify tumour type. The protein corona of the top model-contributing nanosensor was interrogated using quantitative proteomics, resulting in the identification of tumour ecosystem-secreted factors, both previously reported and newly discovered, originating from intracranial tumour cells, the tumour microenvironment and the innate immune system of patients with glioblastoma and meningioma. Newly discovered factors elicited linear nanosensor responses and were elevated in one or both tumour types, matching the original protein corona enrichment. This investigation reveals that a perception-based detection of disease in blood can identify biomarkers responsible for the signal and also amplify cancer detection signals by detecting factors beyond tumour cells, thereby recruiting the entire tumour ecosystem for cancer diagnosis.

AIMS/OBJECTIVE:Glial tumours of germ cell origin are relatively rare in men, occurring predominantly after chemotherapy. Many exhibit low-grade histological features within a spectrum that includes teratomas with mature glial/ganglioglial elements and pure low-grade tumours with glial/ganglioglial phenotype (LGGT) that resemble gliomas/gangliogliomas of the central nervous system. Because foci of glial differentiation are very often seen in association with embryonic-type neuroectodermal tumour (ENT), we hypothesise that LGGTs may represent differentiation of embryonic-type neuroectodermal elements of teratoma and/or ENT. METHODS AND RESULTS/RESULTS:To address this hypothesis, we compared LGGTs, ENT, non-teratomas, and teratomas using microRNA and DNA methylation analyses. Seven LGGTs underwent microRNA-371~373 analysis and genomic methylation profiling. Evidence of a prior or concurrent germ cell tumour component containing embryonic neuroectoderm (including overt ENT) was present in 4 LGGTs. None of the tested LGGTs were positive for miR-371a-3p, with three cases demonstrating low levels of expression within the so-called "grey zone". Unsupervised clustering based on microRNA-371~373 showed two clusters, one comprising non-teratomas and another including teratomas, ENTs, and LGGTs. Clustering according to top-differentially methylated probes did not demonstrate a clear separation according to histology. Genome-wide assessment of mean methylation levels using violin plots demonstrated that LGGT show a methylation profile "intermediate" between ENT and teratoma. CONCLUSIONS:These results suggest that LGGTs of germ cell origin result from the maturation of ENT components.

Thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4d-UT) is an uncommon, aggressive lung neoplasm associated with smoking and characterized by loss of SMARCA4 (BRG-1) expression. Although originally considered to be a primary sarcoma, there is growing evidence that these lesions may represent transformation of conventional non-small cell carcinoma. In this study, we probe this relationship based on the clinical, histologic and molecular findings of 18 SMARCA4-deficient malignancies of the lung. Cases diagnosed as SMARCA4d-UT and SMARCA4-deficient carcinoma were retrospectively reviewed, including histologic and immunophenotypic features, and next generation sequencing studies. Of the 18 tumors, 5 were considered to represent undifferentiated SMARCA4d-UT, and 13 SMARCA4-deficient carcinomas, including 11 adenocarcinomas, 1 squamous cell carcinoma, and 1 poorly differentiated non-small cell carcinoma. All 13 carcinomas had a morphologically identifiable undifferentiated component. Survival outcomes were similar in both SMARCA4d-UT and carcinomas. Genetic alterations often seen in lung cancer were identified in 8 cases, including mutations in EGFR (in 2 SMARCA4-deficient adenocarcinomas), KRAS (1 SMARCA4d-UT and 1 SMARCA4-deficient adenocarcinoma), MAP2K1 (1 SMARCA4-deficient adenocarcinoma), and a gene fusion involving EML4::ALK (1 SMARCA4d-UT). The patient with EML4::ALK fusion was treated with alectinib with partial response. Fusions involving BRAF::CHCHD3 and FGFR1::FILIP1 were identified in 2 SMARCA4-deficient adenocarcinomas. High expression of PD-L1 (TPS >50 %) was seen in 12 cases (67 %). These finding further suggest that SMARCA4d-UT and carcinomas with SMARCA4 loss may be on the same spectrum of disease, and accurate histologic distinction between these lesions may be challenging. A unified terminology may be beneficial for appropriate diagnosis and treatment.

DNA methylation-based classification is now central to contemporary neuro-oncology, as highlighted by the World Health Organization (WHO) classification of central nervous system (CNS) tumors. We present the Heidelberg CNS Tumor Methylation Classifier version 12.8 (v12.8), trained on 7,495 methylation profiles, which expands recognized entities from 91 classes in version 11 (v11) to 184 subclasses. This expansion is a result of newly identified tumor types discovered through our large online repository and global collaborations, underscoring CNS tumor heterogeneity. The random forest-based classifier achieves 95% subclass-level accuracy, with its well-calibrated probabilistic scores providing a reliable measure of confidence for each classification. Its hierarchical output structure enables interpretation across subclass, class, family, and superfamily levels, thereby supporting clinical decisions at multiple granularities. Comparative analyses demonstrate that v12.8 surpasses previous versions and conventional WHO-based approaches. These advances highlight the improved precision and practical utility of the updated classifier in personalized neuro-oncology.

PURPOSE/OBJECTIVE:Histopathological grading of IDH-mutant astrocytomas demonstrates limited prognostic accuracy. However, DNA methylation subclassification has demonstrated improved prognostication beyond histological grading. This study aimed to investigate the associations between imaging features, tumor volumetric data, and DNA methylation grade in IDH-mutant astrocytomas. METHODS:We analyzed imaging features and volumetric data for 72 patients diagnosed with IDH-mutant astrocytomas, who underwent preoperative MRI and DNA methylation profiling. VASARI features and multicompartmental volumetrics were evaluated. Logistic regression was used to identify imaging predictors of methylation subclass, WHO histologic grade, copy number variation (CNV), and CDKN2A/B homozygous deletion. Univariable and multivariable Cox proportional hazard models were also developed to assess these variables' influence on overall survival and progression-free survival. RESULTS:Patients were classified into 27 methylation high-grade (A_IDH_HG) and 45 methylation low-grade (A_IDH_LG) tumors. Tumor volumes and proportions varied by methylation grade, CNV status, and WHO histologic grade, but not by CDKN2A/B status. Imaging features distinguished methylation subclasses with 75% accuracy (AUC = 0.77). Methylation high-grade subclass was associated with imaging features such as midline crossing, ependymal extension, and poorly defined enhancing margins. Predictive performance for WHO histologic grade, CNV status, and CDKN2A/B deletion was moderate (AUC = 0.67, 0.69, and 0.65, respectively). Methylation grade, CDKN2A/B status, VASARI features, and proportions of edema and non-contrast enhancing tumor were significantly associated with survival. CONCLUSION/CONCLUSIONS:MRI-derived imaging features facilitate noninvasive prediction of DNA methylation subclass in IDH-mutant astrocytomas.