Intractable epilepsy due to angiocentric glioma: A case report and minireview

Cortically Based Brain Tumors in Children: A Decision-Tree Approach in the Radiology Reading Room

Cortically based brain tumors in children constitute a unique set of tumors with variably aggressive biologic behavior. Because radiologists play an integral role on the multidisciplinary medical team, a clinically useful and easy-to-follow flow chart for the differential diagnoses of these complex brain tumors is essential. This proposed algorithm tree provides the latest insights into the typical imaging characteristics and epidemiologic data that differentiate the tumor entities, taking into perspective the 2021 World Health Organization's classification and highlighting classic as well as newly identified pathologic subtypes by using current molecular understanding.

EGR1-Driven METTL3 Activation Curtails VIM-Mediated Neuron Injury in Epilepsy

Uncovering mechanisms underlying epileptogenesis aids in preventing further epilepsy progression and to lessen seizure severity and frequency. The purpose of this study is to explore the antiepileptogenic and neuroprotective mechanisms of EGR1 in neuron injuries encountered in epilepsy. Bioinformatics analysis was conducted to identify the key genes related to epilepsy. The mice were rendered epileptic using the kainic acid protocol, followed by measurement of seizure severity, high amplitude and frequency, pathological changes of hippocampal tissues and neuron apoptosis. Furthermore, an in vitro epilepsy model was constructed in the neurons isolated from newborn mice, which was then subjected to loss- and gain-of-function investigations, followed by neuron injury and apoptosis assessment. Interactions among EGR1, METTL3, and VIM were analyzed by a series of mechanistic experiments. In the mouse and cell models of epilepsy, VIM was robustly induced. However, its knockdown reduced hippocampal neuron injury and apoptosis. Meanwhile, VIM knockdown decreased inflammatory response and neuron apoptosis in vivo. Mechanistic investigations indicated that EGR1 transcriptionally activated METTL3, which in turn downregulated VIM expression through m6A modification. EGR1 activated METTL3 and reduced VIM expression, thereby impairing hippocampal neuron injury and apoptosis, preventing epilepsy progression. Taken together, this study demonstrates that EGR1 alleviates neuron injuries in epilepsy by inducing METTL3-mediated inhibition of VIM, which provides clues for the development of novel antiepileptic treatments.

Benign Glioma

Benign glioma broadly refers to a heterogeneous group of slow-growing glial tumors with low proliferative rates and a more indolent clinical course. These tumors may also be described as "low-grade" glioma (LGG) and are classified as WHO grade I or II lesions according to the Classification of Tumors of the Central Nervous System (CNS) (Louis et al. in Acta Neuropathol 114:97-109, 2007). Advances in molecular genetics have improved understanding of glioma tumorigenesis, leading to the identification of common mutation profiles with significant treatment and prognostic implications. The most recent WHO 2016 classification system has introduced several notable changes in the way that gliomas are diagnosed, with a new emphasis on molecular features as key factors in differentiation (Wesseling and Capper in Neuropathol Appl Neurobiol 44:139-150, 2018). Benign gliomas have a predilection for younger patients and are among the most frequently diagnosed tumors in children and young adults (Ostrom et al. in Neuro Oncol 22:iv1-iv96, 2020). These tumors can be separated into two clinically distinct subgroups. The first group is of focal, well-circumscribed lesions that notably are not associated with an increased risk of malignant transformation. Primarily diagnosed in pediatric patients, these WHO grade I tumors may be cured with surgical resection alone (Sturm et al. in J Clin Oncol 35:2370-2377, 2017). Recurrence rates are low, and the prognosis for these patients is excellent (Ostrom et al. in Neuro Oncol 22:iv1-iv96, 2020). Diffuse gliomas are WHO grade II lesions with a more infiltrative pattern of growth and high propensity for recurrence. These tumors are primarily diagnosed in young adult patients, and classically present with seizures (Pallud et al. Brain 137:449-462, 2014). The term "benign" is a misnomer in many cases, as the natural history of these tumors is with malignant transformation and recurrence as grade III or grade IV tumors (Jooma et al. in J Neurosurg 14:356-363, 2019). For all LGG, surgery with maximal safe resection is the treatment of choice for both primary and recurrent tumors. The goal of surgery should be for gross total resection (GTR), as complete tumor removal is associated with higher rates of tumor control and seizure freedom. Chemotherapy and radiation therapy (RT), while not typically a component of first-line treatment in most cases, may be employed as adjunctive therapy in high-risk or recurrent tumors and in some select cases. The prognosis of benign gliomas varies widely; non-infiltrative tumor subtypes generally have an excellent prognosis, while diffusely infiltrative tumors, although slow-growing, are eventually fatal (Sturm et al. in J Clin Oncol 35:2370-2377, 2017). This chapter reviews the shared and unique individual features of the benign glioma including diffuse glioma, pilocytic astrocytoma and pilomyxoid astrocytoma (PMA), subependymal giant cell astrocytoma (SEGA), pleomorphic xanthoastrocytoma (PXA), subependymoma (SE), angiocentric glioma (AG), and chordoid glioma (CG). Also discussed is ganglioglioma (GG), a mixed neuronal-glial tumor that represents a notable diagnosis in the differential for other LGG (Wesseling and Capper 2018). Ependymomas of the brain and spinal cord, including major histologic subtypes, are discussed in other chapters.

Neuroimaging features of angiocentric glioma: A case series and systematic review

BACKGROUND AND PURPOSE

Angiocentric gliomas (AGs) are epileptogenic low-grade gliomas in young patients. We aimed to investigate the MRI findings of AGs and systematically review previous publications and three new cases.

METHODS

We searched PubMed, Elsevier's abstract and citation database, and Embase databases and included 50 patients with pathologically proven AGs with analyzable preoperative MRI including 3 patients from our institution and 47 patients from 38 publications (median age, 13 years [range, 2-83 years]; 35 men). Two board-certified radiologists reviewed all images. The relationships between seizure/epilepsy history and MRI findings were statistically analyzed. Moreover, clinical and imaging differences were evaluated between supratentorial and brainstem AGs.

RESULTS

Intratumoral T1-weighted high-intensity areas, stalk-like signs, and regional brain parenchymal atrophy were observed in 23 out of 50 (46.0%), 10 out of 50 (20.0%), and 14 out of 50 (28.0%) patients, respectively. Intratumoral T1-weighted high-intensity areas were observed significantly more frequently in patients with stalk-like signs (positive, 9/10 vs. negative, 14/40, p = .0031) and regional atrophy (13/14 vs. 10/36, p = .0001). There were significant relationships between the length of seizure/epilepsy history and presence of intratumoral T1-weighted high-intensity area (median 3 years vs. 0.5 years, p = .0021), stalk-like sign (13.5 vs. 1 year, p < .0001), and regional atrophy (14 vs. 0.5 years, p < .0001). Patients with brainstem AGs (n = 7) did not have a seizure/epilepsy history and were significantly younger than those with supratentorial AGs (median, 5 vs. 13 years, p < .0001, respectively).

CONCLUSIONS

Intratumoral T1-weighted high-intensity areas, stalk-like signs, and regional brain atrophy were frequent imaging features in AG. We also found that affected age was different between supratentorial and brainstem AGs.

Angiocentric glioma: A case report and review of the literature

BACKGROUND

Angiocentric glioma (AG) is a rare, low-grade glioma with slow growth. In 2007, AG was first classified as a solid tumor according to the WHO classification of the central nervous system (WHO class I). The outcome and prognosis of most of the cases are very good, but a few cases with tumor metastasis and disease progression, even death, have been reported. We report a case and systematically analyze previous literature to increase our understanding of the disease and determine the factors that may affect disease progression to make prognostic judgments.

CASE PRESENTATION

A young male patient complained of a 3-year history of epilepsy. Anti-epileptic drug treatment was ineffective. An imaging examination revealed a lesion in the left parietal cortex area. Thus, the lesion was completely resected. The pathological diagnosis was angiocentric glioma. During a follow-up of two years, the patient had epilepsy relief controlled by sodium valproate and a disease-free period.

CONCLUSION

AG is an epilepsy-related low-grade glioma that heals after complete resection in most reported cases. However, few reported cases have had disease progression and death. This result may be due to the pathological complexity of the diseased tissue. In addition, AG is usually found to have an MYB-QKI rearrangement on genetic analysis. Due to the small number of reported cases and studies, our understanding and knowledge of this disease are still lacking. The potential malignant changes and prognostic factors need to be verified in more than clinical cases and basic research in the future.

Angiocentric Glioma: Report of a Rare Case Presenting with Psychosis

Angiocentric glioma (AG), first described in 2005, was included as a distinct entity in the 2007 World Health Organization Classification of Tumors of the Central Nervous System. It is a very rare cerebrocortical tumor mainly affecting children and young adults with a history of intractable partial seizures. The histopathological features of this entity are perivascular arrangement of monomorphic, bipolar spindled cells with subpial aggregation of tumor cells and variable neuroparenchymal colonization. Of uncertain histogenesis, this is a stable/slowly growing tumor. Prognosis following total surgical resection is favorable. We describe an AG in a 16-year-old, intellectually disabled, male patient, with psychosis. This is a rare presentation with only one such case in literature. Patient's symptoms ameliorated following surgery.

Clinical attributes and surgical outcomes of angiocentric gliomas

Angiocentric gliomas (AG) are exceedingly rare low-grade neoplasms which often present in the form of intractable epilepsy within younger patients. The current study extensively reviews all reported cases which were pathologically verified as AG in the literature to analyze clinical attributes and surgical outcomes of this neoplasm. There were 88 patients with AG reported in the literature consisting mostly of pediatric cases. The sex distribution consisted of 45 males and 36 females with the remaining seven cases not documenting sex. The average age of initial diagnosis was 16years with almost half of all diagnosed patients being within the first decade of life. In cases where extent of resection was reported, gross total resection (GTR) was achieved in 54 patients, subtotal resection (STR) in 16, and biopsy only in three. Post-operative complications were transient and only occurred in three patients with no reports of death following surgery. Only five cases reported tumor recurrence on follow-up. Eight patients had seizure recurrence post-operatively and GTR offered improved rates of seizure control when compared to STR (p=0.0005). Nearly half of the cases of AG are diagnosed within the first decade of life and they usually manifest with intractable seizures. GTR appears to offer better seizure control in the post-operative period. Surgical resection is the mainstay therapy for AG as post-operative complications and tumor recurrence remain uncommon. Since the number of reported cases is limited, future studies with longer follow-up periods will help elaborate more long-term outcomes.

Cystoid angiocentric glioma: A case report and literature review

Angiocentric glioma is a rare subtype of neuroepithelial tumor that is associated with a history of epilepsy. We report a case of cystoid angiocentric glioma associated with an area of calcification. This 25 year old male patient presented with tonic clonic spasm. He underwent craniotomy with complete resection of the lesion. Pathologic specimen showed monomorphous bipolar cells with angiocentric growth pattern.

[A unusual brain cortical tumor: angiocentric glioma]

We report the case of an 11-year-old girl, who was admitted for surgery of an epilepsy-associated brain tumor. The radiological and clinical hypothesis was dysembryoplasic neuroepithelial tumor. Histopathological examination revealed a tumoral proliferation composed of spindle-shaped cells with palisade arrangements around vessels. Tumor cells have small, round and regular nuclei without atypia or mitosis. On immunohistochemistry, the neoplastic cells strongly expressed GFAP and showed a characteristic cytoplasmic dot-like staining with EMA (epithelial membrane antigen). Ki-67 labeling index was low. Molecular analysis failed to reveal the V600E mutation of BRAF gene. The patient was free of seizures after surgery. Angiocentric glioma is a rare brain tumor occuring preferably in children and young adults and is associated with seizures. The precise histogenesis remains debated. The treatment of choice is total resection. The prognosis is favorable if totally resected.