In Japan, brain Tumor (Glioma) is managed by neurosurgerys. Glioma is a group of primary brain tumors that arise from glial cells (astrocytes, oligodendrocytes, ependymal cells) and accounts for approximately 27% of all primary brain tumors and 80% of malignant primary brain tumors. The age-adjusted annual incidence is roughly 6 per 100,000 in the United States, with a slight male predominance and peak between ages 55 and 70.
Gliomas (ICD-10: C71.x for malignant neoplasm of brain; D33.x for benign; D43.x for uncertain behavior) are primary central nervous system tumors arising from cells of glial lineage — astrocytes, oligodendrocytes, and ependymal cells. The 2021 WHO Classification of CNS Tumors (CNS5) integrates histology with molecular features into the diagnosis, replacing the older purely-histologic system. Adult-type diffuse gliomas now include three families: astrocytoma IDH-mutant (grades 2, 3, 4); oligodendroglioma IDH-mutant and 1p/19q-codeleted (grades 2, 3); and glioblastoma IDH-wildtype (grade 4). Pediatric-type diffuse gliomas (low-grade and high-grade), circumscribed astrocytic gliomas (pilocytic astrocytoma, pleomorphic xanthoastrocytoma, subependymal giant cell astrocytoma), glioneuronal and neuronal tumors, and ependymal tumors form additional families.
The key symptoms of Brain Tumor (Glioma) are: Headache that is new, persistent, progressively worsening, worse in the morning, or worsened by Valsalva (coughing, straining); present in 50-70% of glioma patients at diagnosis., New-onset focal or generalized seizures, the first symptom in 40-60% of low-grade gliomas and 20-30% of glioblastomas., Progressive focal neurological deficit: hemiparesis, hemisensory loss, hemianopia, or cranial-nerve palsy depending on tumor location., Aphasia (word-finding difficulty, expressive or receptive language impairment) with dominant frontal or temporal tumors., Cognitive change: slowed processing, memory impairment, executive dysfunction, apathy, personality or behavioral change., Nausea and vomiting, especially morning emesis, from raised intracranial pressure or posterior fossa involvement., Papilledema, visual blurring, or diplopia from raised intracranial pressure or direct optic-pathway involvement..
Diagnosis begins with brain MRI with and without gadolinium contrast, which is the cornerstone imaging study. Typical glioblastoma shows an irregular ring-enhancing mass with central necrosis, surrounding T2/FLAIR hyperintensity (edema and infiltrating tumor), and mass effect. Low-grade gliomas are usually non-enhancing T2/FLAIR-hyperintense lesions. Advanced MRI sequences — perfusion (MR perfusion CBV), diffusion (apparent diffusion coefficient), magnetic resonance spectroscopy (choline-to-N-acetylaspartate ratio, 2-hydroxyglutarate detection in IDH-mutant tumors), and diffusion tensor imaging tractography — refine diagnosis and operative planning. Functional MRI and direct cortical stimulation are used for eloquent-cortex tumors. CT is reserved for emergency assessment (hemorrhage, herniation) and for patients who cannot undergo MRI. Histological and molecular diagnosis requires tissue obtained at maximal safe resection or stereotactic biopsy. The WHO 2021 classification mandates integrated histologic-plus-molecular diagnosis: IDH1/IDH2 mutation status (immunohistochemistry and sequencing), 1p/19q codeletion (FISH or next-generation sequencing), MGMT promoter methylation, CDKN2A/B status, EGFR amplification, TERT promoter mutation, and additional markers depending on suspected entity. Comprehensive next-generation sequencing panels are now standard at major academic centers. Staging is unnecessary for most adult diffuse gliomas because they are confined to the central nervous system; spinal MRI is added for medulloblastoma, ependymoma, and selected diffuse midline gliomas. Multidisciplinary tumor-board review is the standard of care for treatment planning.
Prognosis is highly dependent on histologic and molecular type. For IDH-wildtype glioblastoma, median overall survival with optimal Stupp protocol plus Tumor Treating Fields is 20-21 months, with 5-year survival around 13%; MGMT-methylated tumors do best, with median survival over 30 months in some series. For IDH-mutant grade 4 astrocytoma, median survival is 5-8 years. IDH-mutant grade 2-3 astrocytomas typically have 6-10 year median survival with combined chemo-radiation. 1p/19q-codeleted oligodendrogliomas have the best outcomes — median survival 14-18 years with combined modality treatment. Pilocytic astrocytoma (WHO grade 1) is often curable surgically, with 10-year survival above 90%. Pediatric diffuse midline glioma H3 K27-altered remains a devastating disease with median survival under 12 months. Modifiable prognostic factors include extent of surgical resection, treatment at high-volume centers, completion of planned multimodal therapy, and management of seizures and treatment toxicity. Unmodifiable factors include age, performance status at diagnosis, and molecular profile.
Glioma care requires a multidisciplinary team including neurosurgery, neuro-oncology, radiation oncology, neuropathology with molecular diagnostic capability, neuropsychology, and rehabilitation medicine. Treatment at high-volume academic neurosurgical centers is associated with longer survival and lower complication rates than treatment at low-volume centers. Clinical trial access is also concentrated at major centers.
Find specialists →Hospital recovery after craniotomy: 3-7 days. Initial functional recovery: 4-8 weeks with neurorehabilitation if needed. Concurrent chemoradiation: 6 weeks of daily treatment followed by 4-week break. Adjuvant temozolomide cycles: 6 cycles over 6 months. Tumor Treating Fields: continued at least 18 hours/day for months to years until progression. Surveillance MRI every 2-3 months in the first 1-2 years, then every 4-6 months.
Aerobic and resistance exercise is recommended during and after treatment when safely tolerated. Even 20-30 minutes of walking 3-5 times per week reduces fatigue, improves mood, and supports cognitive function. Avoid contact sports and activities with fall risk while seizures are uncontrolled or anticoagulation is needed. Coordinate with neurorehabilitation for tailored programs after neurological deficit.
Choose a neurosurgeon with a dedicated brain-tumor practice and access to intraoperative MRI, awake mapping, and 5-ALA fluorescence. Confirm a multidisciplinary tumor board reviews the case and that molecular profiling (IDH, 1p/19q, MGMT, full sequencing panel) is performed. For pediatric tumors, choose a pediatric neuro-oncology center.
Medically reviewed by AIHealz Medical Editorial Board · May 13, 2026
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