Diffuse midline glioma of the cervical spinal cord with H3 K27M genotype phenotypically mimicking anaplastic ganglioglioma: a case report and review of the literature

Clinico-Pathological Features of Diffuse Midline Glioma, H3 K27-Altered in Adults: A Comprehensive Review of the Literature with an Additional Single-Institution Case Series

Background: Diffuse midline glioma (DMG), H3 K27-altered, is a WHO grade 4 malignant glioma located at midline structures, including the thalamus, brainstem and spinal cord. While H3 K27-altered DMG is more common in pediatric age in which it shows a uniformly aggressive clinical behavior, its occurrence is relatively unusual among adults, and its clinico-pathological and prognostic features are not fully characterized in this age group. Methods: In this present paper, a review of the literature, including all cases of adult H3 K27-altered DMG published from January 2010 to December 2023 was performed, and the following clinical parameters were evaluated: sex, age (median and range), anatomic site, median follow-up, leptomeningeal dissemination, local recurrence and treatment. In addition, the clinico-pathological features of three additional adult cases from our retrospective series were also reported and discussed. Results: All tumors from our series exhibited a high-grade morphology with brisk mitotic activity; microvascular proliferation and necrosis were seen only in one case. The immunohistochemical loss of H3 K27me3 along with diffuse and strong immunoreactivity for H3 K27M was found in all cases, leading to the diagnosis of H3 K27-altered DMG. Conclusions: The literature review showed that adult H3 K27-altered DMG more frequently occurred in males aged between 18 and 40 years. The thalamus was the most affected site, followed by the brainstem and spinal cord, in both sex groups. Adult tumors exhibited less aggressive clinical behavior, with leptomeningeal dissemination and local recurrence reported in only 23.78% and 37.75% of cases, respectively.

Ganglioglioma with anaplastic/high-grade transformation: Histopathologic, molecular, and epigenetic characterization of 3 cases

Ganglioglioma (GG) with anaplasia (anaplastic ganglioglioma) is a rare and controversial diagnosis. When present, anaplasia involves the glial component of the tumor, either at presentation or at recurrence. To date, most published cases lack molecular characterization. We describe the histologic and molecular features of 3 patients presenting with BRAF p. V600E-mutant GG (CNS WHO grade 1) with high-grade glial transformation at recurrence. The tumors occurred in pediatric patients (age 9-16 years) with time to recurrence from 20 months to 7 years. At presentation, each tumor was low-grade, with a BRAFV600E-positive ganglion cell component and a glial component resembling pleomorphic xanthoastrocytoma (PXA) or fibrillary astrocytoma. At recurrence, tumors resembled anaplastic PXA or high-grade astrocytomas without neuronal differentiation. CDKN2A homozygous deletion (HD) was absent in all primary tumors. At recurrence, 2 cases acquired CDKN2A HD; the third case showed loss of p16 and MTAP immunoexpression, but no CDKN2A/B HD or mutation was identified. By DNA methylation profiling, all primary and recurrent tumors either grouped or definitely matched to different methylation classes. Our findings indicate that malignant progression of the glial component can occur in GG and suggest that CDKN2A/B inactivation plays a significant role in this process.

H3K27-Altered Diffuse Glioma of the Spinal Cord in Adult Patients: A Qualitative Systematic Review and Peculiarity of Radiological Findings

Background: Primary spinal cord diffuse gliomas (SpDG) are rare tumors that may harbor, like diffuse intrinsic pontine gliomas (DIPG), H3K27M mutations. According to the WHO (2021), SpDGs are included in diffuse midline H3K27-altered gliomas, which occur more frequently in adults and show unusual clinical presentation, neuroradiological features, and clinical behavior, which differ from H3 G34-mutant diffuse hemispheric glioma. Currently, homogeneous adult-only case series of SpDG, with complete data and adequate follow-up, are still lacking. Methods: We conducted a qualitative systematic review, focusing exclusively on adult and young adult patients, encompassing all studies reporting cases of primitive, non-metastatic SpDG with H3K27 mutation. We analyzed the type of treatment administered, survival, follow-up duration, and outcomes. Results: We identified 30 eligible articles published between 1990 and 2023, which collectively reported on 62 adult and young adult patients with primitive SpDG. Postoperative outcomes were assessed based on the duration of follow-up, with outcomes categorized as either survival or mortality. Patients who underwent surgery were followed up for a mean duration of 17.37 months, while those who underwent biopsy had a mean follow-up period of 14.65 months. Among patients who were still alive, the mean follow-up duration was 18.77 months. The radiological presentation of SpDG varies widely, indicating its lack of uniformity. Conclusion: Therefore, we presented a descriptive scenario where SpDG was initially suspected to be a meningioma, but was later revealed to be a malignant SpDG with H3K27M mutation.

Approach to diagnosis, evaluation, and treatment of generalized and nonlocal dysesthesia: A review

Dysesthesia is an abnormal sensation in the skin that occurs in the absence of any extraordinary stimulus or other primary cutaneous disorders, excluding any delusions or tactile hallucinations. Clinicians have characterized dysesthesias to include sensations such as burning, tingling, pruritus, allodynia, hyperesthesia, or anesthesia. The etiology and pathogenesis of various generalized dysesthesias is largely unknown, though many dysesthesias have been associated with systemic pathologies including malignancy, infection, autoimmune disorders, and neuropathies. Dermatologists are often the first-line clinicians for patients presenting with such cutaneous findings, thus it is crucial for these physicians to be able to methodically work-up generalized dysesthesias to build a working differential diagnosis, follow up with key labs and/or imaging, and offer patients evidence-based treatment to relieve their symptoms. This broad literature review is an attempt to centralize key studies, cases, and series to help guide dermatologists in their assessment and evaluation of complaints of abnormal cutaneous sensations.

Dissecting the Methylomes of EGFR-Amplified Glioblastoma Reveals Altered DNA Replication and Packaging, and Chromatin and Gene Silencing Pathways

Glioblastoma IDH wildtype is the most frequent brain tumor in adults. It shows a highly malignant behavior and devastating outcomes. To date, there is still no targeted therapy available; thus, patients' median survival is limited to 12-15 months. Epithelial growth factor receptor (EGFR) is an interesting targetable candidate in advanced precision medicine for brain tumor patients. In this study, we performed integrated epigenome-wide DNA-methylation profiling of 866,895 methylation specific sites in 50 glioblastoma IDH wildtype samples, comparing EGFR amplified and non-amplified glioblastomas. We found 9849 significantly differentially methylated CpGs (DMCGs) with Δβ ≥ 0.1 and p-value < 0.05 in EGFR amplified, compared to EGFR non-amplified glioblastomas. Of these DMCGs, 2380 were annotated with tiling (2090), promoter (117), gene (69) and CpG islands (104); 7460 are located at other loci. Interestingly, the list of differentially methylated genes allocated eleven functionally relevant RNAs: five miRNAs (miR1180, miR1255B1, miR126, miR128-2, miR3125), two long non-coding RNAs (LINC00474, LINC01091), and four antisense RNAs (EPN2-AS1, MNX1-AS2, NKX2-2-AS1, WWTR1-AS1). Gene ontology (GO) analysis showed enrichment of "DNA replication-dependent nucleosome assembly", "chromatin silencing at rDNA", "regulation of gene silencing by miRNA", "DNA packaging", "posttranscriptional gene silencing", "gene silencing by RNA", "negative regulation of gene expression, epigenetic", "regulation of gene silencing", "protein-DNA complex subunit organization", and "DNA replication-independent nucleosome organization" pathways being hypomethylated in EGFR amplified glioblastomas. In summary, dissecting the methylomes of EGFR amplified and non-amplified glioblastomas revealed altered DNA replication, DNA packaging, chromatin silencing and gene silencing pathways, opening potential novel targets for future precision medicine.

Methylome Profiling of PD-L1-Expressing Glioblastomas Shows Enrichment of Post-Transcriptional and RNA-Associated Gene Regulation

Glioblastomas are the most frequent primary brain tumors in adults. They show highly malignant behavior and devastating outcomes. Since there are still no targeted therapies available, median survival remains in the range of 12 to 15 months for glioblastoma patients. Programmed Cell Death Ligand 1 (PD-L1) is a promising novel candidate in precision medicine. Here, we performed integrated epigenome-wide methylation profiling of 866,895 methylation-specific sites in 20 glioblastoma samples comparing PD-L1 high- (i.e., TPS (tumor proportion score) > 30%) and PD-L1 low-expressing glioblastomas (i.e., TPS < 10%). We found 12,597 significantly differentially methylated CpGs (DMCG) (Δβ ≥ 0.1 and p-value < 0.05) in PD-L1 high- compared with PD-L1 low-expressing glioblastomas. These DMCGs were annotated to 2546 tiling regions, 139 promoters, 107 genes, and 107 CpG islands. PD-L1 high-expressing glioblastomas showed hypomethylation in 68% of all DMCGs. Interestingly, the list of the top 100 significantly differentially methylated genes showed the enrichment of regulatory RNAs with 19 DMCGs in miRNA, snoRNAs, lincRNAs, and asRNAs. Gene Ontology analysis showed the enrichment of post-transcriptional and RNA-associated pathways in the hypermethylated gene regions. In summary, dissecting the methylomes depending on PD-L1 status revealed significant alterations in RNA regulation and novel molecular targets in glioblastomas.

Pediatric spinal cord diffuse midline glioma, H3 K27-altered with intracranial and spinal leptomeningeal spread: A case report

Primary spinal cord high-grade gliomas, including those histologically identified as glioblastoma (GBM), are a rare entity in the pediatric population but should be considered in the differential diagnosis of intramedullary lesions. Pediatric spinal cord high-grade gliomas have an aggressive course with poor prognosis. The aim of this case report is to present a 15-year-old female adolescent with histopathologically confirmed spinal cord GBM with H3F3A K27 M mutation consistent with a diffuse midline glioma (DMG), H3 K27-altered, CNS WHO grade 4 with leptomeningeal seeding on initial presentation. As imaging features of H3 K27-altered DMGs are non-specific and may mimic more frequently encountered neoplastic diseases as well as demyelinating disorders, severe neurological deficits at presentation with short duration, rapid progression, and early leptomeningeal seeding should however raise the suspicion for a pediatric-type diffuse high-grade glioma like DMG, H3 K27-altered.

EGFR Amplification Is a Phenomenon of IDH Wildtype and TERT Mutated High-Grade Glioma: An Integrated Analysis Using Fluorescence In Situ Hybridization and DNA Methylome Profiling

Gliomas are the most common intrinsic brain tumors in adults, and in accordance with their clinical behavior and patients’ outcome, they are graded by the World Health Organization (WHO) classification of brain tumors. One very interesting candidate for targeted tumor therapy may be epidermal growth factor receptor (EGFR) amplification. Here, we performed an integrated comparative analysis of EGFR amplification in 34 glioma samples using standard fluorescence in situ hybridization (FISH) and Illumina EPIC Infinium Methylation Bead Chip and correlated results with molecular glioma hallmarks. We found that the EPIC analysis showed the same power of detecting EGFR amplification compared with FISH. EGFR amplification was detectable in high-grade gliomas (25%). Moreover, EGFR amplification was found to be present solely in IDH wildtype gliomas (26%) and TERT mutated gliomas (27%), occurring independently of MGMT promoter methylation status and being mutually exclusive with 1p/19q codeletion (LOH). In summary, EPIC Bead Chip analysis is a reliable tool for detecting EGFR amplification and is comparable with the standard method FISH. EGFR amplification is a phenomenon of IDH wildtype TERT mutated high-grade gliomas.

A patient with two gliomas with independent oligodendroglioma and glioblastoma biology proved by DNA-methylation profiling: a case report and review of the literature

Here, we report on a patient presenting with two histopathologically distinct gliomas. At the age of 42, the patient underwent initial resection of a right temporal oligodendroglioma IDH mutated 1p/19q co-deleted WHO Grade II followed by adjuvant radiochemotherapy with temozolomide. 15 months after initial diagnosis, the patient showed right hemispheric tumor progression and an additional new left frontal contrast enhancement in the subsequent imaging. A re-resection of the right-sided tumor and resection of the left frontal tumor were conducted. Neuropathological work-up showed recurrence of the right-sided oligodendroglioma with features of an anaplastic oligodendroglioma WHO Grade III, but a glioblastoma WHO grade IV for the left frontal lesion. In depth molecular profiling revealed two independent brain tumors with distinct molecular profiles of anaplastic oligodendroglioma IDH mutated 1p/19q co-deleted WHO Grade III and glioblastoma IDH wildtype WHO grade IV. This unique and rare case of a patient with two independent brain tumors revealed by in-depth molecular work-up and epigenomic profiling emphasizes the importance of integrated work-up of brain tumors including methylome profiling for advanced patient care.

Case Report: Five Adult Cases of H3K27-Altered Diffuse Midline Glioma in the Spinal Cord

Background

Diffuse midline glioma with H3K27-altered (DMG-H3K27a) is a novel tumor entity of the pediatric-type diffuse high-grade tumor in the latest WHO CNS 5. It mostly affects children and is only rarely found in adults. The tumor has a high level of aggressiveness, with a rapid progression and bad prognosis. In adults, the spinal cord is the most common site of DMG-H3K27a. Rare adult cases of primary DMG-H3K27a in the spinal cord were reported in this study, together with clinico-histopathologico-radiographic data.

Methods

From January 2016 to December 2020, we conducted a retrospective study of five adults with primary DMG-H3K27a in the spinal cord, analyzing their clinical, pathohistological, and radiographic datasets from the first diagnosis to follow-up.

Results

All five patients were diagnosed for the first time and were given full treatment. In three of the five patients, post-operative follow-up revealed tumor recurrence. The longest survival of the five patients was 45 months at the time of report submission, while the longest progression-free survival (PFS) following surgery was 20 months. Immunohistochemical studies showed the tumors featured aggressive behavior (grade 4) and were positive for the H3K27M mutation. The radiographic appearances were varied, but they were all initially mistaken as benign. DMG-H3K27a in the spinal cord was characterized by isointense/hyperintense on T1WI and isointense/hyperintense on T2WI, as well as cystic necrosis and peripheral spinal cord edema, as well as central canal enlargement and other types of enhancement.

Conclusion

This is the first case report focusing on adult DMG-H3K27a of the pediatric-type diffuses high-grade gliomas in the spinal cord. In our cases, we discovered the following: 1) adults had a better prognosis with a longer PFS compared with prior pediatric reports; 2) despite aggressive behavior under the microscope, radiographic appearances of the tumors were less aggressive; and 3) adjuvant treatment, including TCM, may have played a role in the prognosis.

Genotypical glioblastoma of the frontal lobe mimicking ganglioglioma: A case report and review of the literature

This case of severe phenotype-genotype mismatch brain tumor morphologically mimicking benign ganglioglioma emphasizes the urgent need for advanced molecular profiling in brain tumor diagnosis in the era of sophisticated molecular profiling.

Integrated analysis of programmed cell death ligand 1 expression reveals increased levels in high-grade glioma

Purpose

Gliomas are the most frequent primary brain tumors of adults. Despite intensive research, there are still no targeted therapies available. Here, we performed an integrated analysis of glioma and programmed cell death ligand 1 (PD-L1) in 90 samples including 58 glioma and 32 control brain tissues.

Methods

To identify PD-L1 expression in glioma, we performed immunohistochemical analysis of PD-L1 tumor proportion score (TPS) using the clinically valid PD-L1 22C3 antibody on 90 samples including controls and WHO grade I–IV gliomas.

Results

We found that PD-L1 is highly expressed in a subfraction of glioma cells. Analysis of PD-L1 levels in different glioma subtypes revealed a strong intertumoral variation of PD-L1 protein. Furthermore, we correlated PD-L1 expression with molecular glioma hallmarks such as MGMT-promoter methylation, IDH1/2 mutations, TERT promoter mutations and LOH1p/19q.

Conclusion

In summary, we found that PD-L1 is highly expressed in a subfraction of glioma, indicating PD-L1 as a potential new marker in glioma assessment opening up novel therapeutic approaches.

Genomic Profiling Identified Novel Prognostic Biomarkers in Chinese Midline Glioma Patients

Background

Molecular characteristics are essential for the classification and grading of gliomas. However, diagnostic classification of midline glioma is still debatable and substantial molecular and clinical heterogeneity within each subgroup suggested that they should be further stratified. Here, we studied the mutation landscape of Chinese midline glioma patients in hope to provide new insights for glioma prognosis and treatment.

Methods

Tissue samples from 112 midline glioma patients underwent next-generation sequencing targeting 425 cancer-relevant genes. Gene mutations and copy number variations were investigated for their somatic interactions and prognostic effect using overall survival data. Pathway-based survival analysis was performed for ten canonical oncogenic pathways.

Results

We identified several currently established diagnostic and prognostic biomarkers of glioma, including TP53 (33%), EGFR (26%), TERT (24%), PTEN (21%), PIK3CA (14%), ATRX (14%), BRAF (13%), and IDH1/2 (6%). Among all genetic aberrations with more than 5% occurrence rate, six mutations and three copy number gains were greatly associated with poor overall survival (univariate, P < 0.1). Of these, TERT mutations (hazard ratio [HR], 3.00; 95% confidence interval [CI], 1.37–6.61; P = 0.01) and PIK3CA mutations (HR, 2.04; 95% CI, 1.08–3.84; P = 0.02) remained significant in multivariate analyses. Additionally, we have also identified a novel MCL1 amplification (found in 31% patients) as a potential independent biomarker for glioma (multivariate HR, 2.78; 95% CI, 1.53–5.08; P < 0.001), which was seldom reported in public databases. Pathway analyses revealed significantly worse prognosis with abnormal PI3K (HR, 1.81; 95% CI, 1.12–2.95; P = 0.01) and cell cycle pathways (HR, 1.97; 95% CI, 1.15–3.37; P = 0.01), both of which stayed meaningful after multivariate adjustment.

Conclusions

In this study, we discovered shorter survival in midline glioma patients with PIK3CA and TERT mutations and with abnormal PI3K and cell cycle pathways. We also revealed a novel prognostic marker, MCL1 amplification that collectively provided new insights and opportunities in understanding and treating midline gliomas.