Diffuse gliomas are a family of neoplastic diseases characterized by widespread infiltration of central nervous system structures by tumor cells displaying glial differentiation. Traditionally characterized by morphologic features of lineage and histologic differentiation, we now understand that diffuse gliomas contain multiple discrete molecular subsets, each with their own clinical and genetic characteristics. In the current molecular era, the World Health Organization 4^th Edition update introduced classes of diffuse glioma according to the status of isocitrate dehydrogenase mutation, 1p/19q co-deletion, histone H3 mutation, and BRAF mutation. Additional studies have demonstrated the subset-specific prognostic significance and grading implications of epidermal growth factor receptor amplification, CDKN2A/B homozygous deletion, TERT promoter mutations, and whole chromosome 7 gain and whole chromosome 10 loss (+7/−10). These findings represent the beginning of the molecular era of diagnosis and grading. Additional studies will likely refine our current conceptions and further advance our ability to stratify risk and direct therapies. In this review, we discuss the current understanding of the molecular classification of diffuse gliomas.

Maximizing the extent of tumor removal and preserving maximal neurological function are always the fundamental objectives in brain tumor surgery. This has motivated neurosurgeons to try various ways to map brain functions before tumor resection. Navigated transcranial magnetic stimulation (nTMS) is a new noninvasive method for brain mapping, which has produced exceptional results in clinical practice in recent years. However, there are still many deficiencies which need to be addressed to make nTMS more suitable for clinical application and neuroscience research. In this review, we highlight the opportunities provided by nTMS mapping, analyze the shortcomings at a theoretical level, and then emphasize the possibilities and prospects of applying multimodal fusion nTMS.

Glioma is the most refractory intracranial tumor, and its diffuse infiltrative growth characteristics make total resection impossible in a biological sense, especially when tumors invade eloquent brain areas. Thus, identifying the equilibrium between tumor resection and functional preservation remains a challenge in glioma surgery. The accurate identification of tumor boundaries, precise mapping of functional boundaries, and an in-depth understanding of functional plasticity are key factors for accomplishing this challenge. This article reviews these three key points and highlights potential perspectives for the development of glioma surgery.

Brain imaging has been broadly applied in neuroscience for more than 40 years. A wide range of studies on glioma have been carried out based on structural and functional imaging to characterize tumor malignancy, search for biomarker, aid the therapeutic process, and predict the prognosis. As the mainstay of modern neuroimaging, magnetic resonance imaging provides superior resolution and multiple contrasts capturing the morphological, vascular, metabolic, and functional properties of glioma. Furthermore, the development of connectivity-based approach and network models innovates our understanding of glioma in terms of functional remodeling and plasticity at various levels. The focus of this presentation is to overview the challenges of glioma characterization based on conventional magnetic resonance imaging and the future perspective of incorporating connectivity-based approaches into the disease management of glioma.

Background and Aim: Glial tumors with astrocytic differentiation are the most common primary malignant brain tumors. Hans Joachim Scherer established histological criteria based on hematoxylin and eosin (H&E) staining, which form the basis of the World Health Organization (WHO) glial tumor grades. The aim of this study was to investigate the incidence of Scherer structures across different classes of WHO grade tumors with astrocytic differentiation and determine whether secondary structures can be used as a grade-defining tool. Materials and Methods: Tumor samples were obtained from 36 patients with central nervous system (CNS) tumors with astrocytic differentiation between February 2018 and March 2019. The study was approved by the Committee on Ethics for Scientific Research, Medical University—Varna “Prof. Dr. Paraskev Stoyanov,” Protocol no. 20 [1] on April 26, 2012. The presence or absence of primary Scherer structures (pseudopalisading necrosis, glomeruloid vascular proliferation) and secondary Scherer structures (subpial palisading, fascicular aggregation, satellitosis around neurons, and blood vessels) was analyzed in H&E stained samples. Results: The samples were divided into two groups: 28 glioblastoma multiforme (GBM) cases and 8 lower grade astrocytoma cases. All 28 GBM cases exhibited pseudopalisading necrosis. Glomeruloid vascular proliferation was present only in 89.3% of the GBM cases. The GBM group also showed 67.9% subpial palisading, 78.5% fascicular aggregation of tumor cells, 96.4% perineuronal, and 100% perivascular satellitosis. The lower grade astrocytoma group had 0% pseudopalisading necrosis and glomeruloid vascular proliferation. Among all cases of lower grade gliomas, 50.0% showed subpial palisading, 87.5% fascicular aggregation, 100% perineuronal, and 100% perivascular satellitosis. Conclusions: Secondary Scherer structures can be considered as natural phenomena in glial tumors but cannot be used as features for grading.

Li-Fraumeni syndrome is an autosomal dominant cancer predisposition syndrome caused by germ line alterations in the tumor suppressor gene TP53, with an incidence of 1 in 5000–1 in 20,000. Li-Fraumeni syndrome is associated with numerous malignancies, including astrocytoma. Here, we report the case of a female patient diagnosed with glioblastoma in the right temporal lobe at the age of 22 years. She was treated with surgery followed by radiation and chemotherapy and achieved a complete response. Not surprisingly, the patient relapsed 7 years later and underwent a second surgery and radiation concurrent with temozolomide followed by chemotherapy with various agents. The patient currently remains tumor-free. Genetic testing revealed that the tumor contained a germ line mutation of TP53 (p.R282W). Pertinent family history included a mother who suffered from leukemia. Therefore, given the patient's medical and family history, we consider this is a case of Li-Fraumeni syndrome associated with glioblastoma. The ethics approval is not applied since the case was in consultation with experts arranged through meeting organizer.

Extraneural metastasis of gliosarcoma (GS) is a rare event. In this report, we describe a 15-year-old girl with a frontal GS who underwent complete resection, but developed tumor recurrence requiring a second operation after 3 years. Eight months after the second operation, she presented with a left postauricular mass. The clinical, neuroimaging, and histopathological findings were described. We also conducted a literature review and identified 26 cases of GS with extraneural metastasis, including the current report. The prognosis of GS with extracranial metastasis was poor, with a median survival of approximately 8.0 months. The common metastatic organs were the lungs (65.4%), liver (34.6%), and skeleton (23.1%). We also discuss the pathogenesis of GS with extraneural metastasis. We report an unusual case of a pediatric patient with GS with extraneural metastasis, with a long survival. GS with extraneural metastasis should be considered as a differential diagnosis in patients with soft-tissue masses. This work was approved by the Ethics Committee of the Faculty of Medicine, Prince of Songkla University, Thailand (REC 62-259-10-1) on September 9, 2019.