Case Report: H3K27M-Mutant Glioblastoma Simultaneously Present in the Brain and Long-Segment Spinal Cord Accompanied by Acute Pulmonary Embolism

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.

Fulminant hemorrhagic course of a thalamic H3 K27-altered diffuse midline glioma in an adult patient: illustrative case

BACKGROUND

H3 K27-altered diffuse midline gliomas (DMGs) are rare tumors, which are, regardless of their histological appearance, classified as World Health Organization grade 4 tumors. They are characterized by a diffuse growth pattern, midline anatomical location, and poor prognosis. Although DMGs occur predominantly in childhood, these tumors can also be found in young adults.

OBSERVATIONS

The authors present a case of a 29-year-old patient who was found unconscious with a Glasgow Coma Scale score of 4, along with abnormal extensor movements and bilateral middilated nonreactive pupils. Computed tomography revealed obstructive hydrocephalus due to an acute hemorrhage in a right thalamic lesion. To drain the hydrocephalus and relieve the ongoing central herniation, emergent placement of a right-sided, and later a left-sided, extraventricular drain was performed. Despite the postoperative resolution of hydrocephalus, the patient died shortly after because of the central brain herniation that had occurred. Brain autopsy revealed a H3 K27-altered DMG in the right thalamus.

LESSONS

Although typically described in the pediatric population and located in the pons, H3 K27-altered DMG should also be considered in young adult patients with midline lesions, particularly if they are located in the thalamus or brainstem. In rare cases, H3 K27-altered DMG may present with an acute tumor-related hemorrhage, leading to a fulminant clinical course.

BRAF-mutated suprasellar glioblastoma mimicking craniopharyngioma: illustrative case

BACKGROUND

Suprasellar masses commonly include craniopharyngiomas and pituitary adenomas. Suprasellar glioblastoma is exceedingly rare with only a few prior case reports in the literature. Suprasellar glioblastoma can mimic craniopharyngioma or other more common suprasellar etiologies preoperatively.

OBSERVATIONS

A 65-year-old male with no significant history presented to the emergency department with a subacute decline in mental status. Work-up revealed a large suprasellar mass with extension to the right inferior medial frontal lobe and right lateral ventricle, associated with significant vasogenic edema. The patient underwent an interhemispheric transcallosal approach subtotal resection of the interventricular portion of the mass. Pathological analysis revealed glioblastoma, MGMT partially methylated, with a BRAF V600E mutation.

LESSONS

Malignant glioblastomas can mimic benign suprasellar masses and should remain on the differential for a diverse set of brain masses with a broad range of radiological and clinical features. For complex cases accessible from the ventricle where the pituitary complex cannot be confidently preserved via a transsphenoidal approach, an interhemispheric approach is also a practical initial surgical option. In addition to providing diagnostic value, molecular profiling may also reveal therapeutically significant gene alterations such as BRAF mutations.

H3F3A K27M Mutation Promotes the Infiltrative Growth of High-Grade Glioma in Adults by Activating β-Catenin/USP1 Signaling

Simple Summary

Gliomas is a primary type of tumor in the central nervous system. High-grade glioma is a malignant cancerous disease and grows rapidly. This study reports the expression of H3.3K27M in high-grade glioma tissues and the association with malignant glioma cell behavior. Moreover, the results suggested that a high expression of H3.3K27M promotes the migration and invasion of glioma cells, leading to a poor prognosis by promoting the infiltration of glioma through aggravating aberrant activation of β-catenin signaling-driven pathway.

Abstract

H3F3A K27M (H3.3K27M) is a newly identified molecular pathological marker in glioma and is strongly correlated with the malignancy of diffuse intrinsic pontine glioma (DIPG). In recent years, accumulating evidence has revealed that other types of glioma also contain the H3.3K27M mutation. However, the role of H3.3K27M in high-grade adult glioma, the most malignant glioma, has not been investigated. In this study, we focused on exploring the expression and function of H3.3K27M in high-grade glioma in adults. We found that H3.3K27M was highly expressed at high levels in some high-grade glioma tissues. Then, we introduced H3.3K27M into H3.3 wild-type glioma cells, U87 cells and LN229 cells. We found that H3.3K27M did not affect the growth of glioma cells in vitro and in vivo; however, the survival of mice with transplanted tumors was significantly reduced. Further investigation revealed that H3.3K27M expression mainly promoted the migration and invasion of glioma cells. Moreover, we confirmed that H3.3K27M overexpression increased the levels of the β-catenin and p-β-catenin (Ser675) proteins, the ubiquitin-specific protease 1 (USP1) mRNA and protein levels, and the enhancer of zeste homolog 2 (EZH2) protein level. In addition, the β-catenin inhibitor XAV-939 significantly attenuated the upregulation of the aforementioned proteins and inhibited the increased migration and invasion caused by the H3.3K27M mutation. Overall, the H3.3K27M mutation in high-grade glioma is a potential biomarker for poor prognosis mainly due to the infiltration of glioma cells that is at least partially mediated by the β-catenin/USP1/EZH2 pathway.