Glioblastoma
Glioblastoma (IDH-wildtype) is the most common and most aggressive primary malignant brain tumor in adults. It is classified as grade 4 in the World Health Organization (WHO) classification and tends to grow rapidly and infiltrate surrounding brain tissue.
Last updated: 2026-06-06
Definition
Glioblastoma is a high-grade tumor arising from the brain's supporting cells (glial cells, particularly astrocytes). In the WHO 2021 classification of central nervous system tumors it is defined as a grade 4 astrocytic tumor. Microscopically it is characterized by marked cell proliferation, microvascular proliferation and areas of necrosis.
Causes and Risk Factors
Most cases are sporadic and no clear cause is identified. The only established environmental risk factor is a history of high-dose ionizing radiation to the head. Certain hereditary syndromes (e.g., Li-Fraumeni, Turcot) carry increased risk. Advanced age increases incidence.
Symptoms
Symptoms depend on tumor location and growth rate. Common features include progressively worsening headache, nausea and vomiting (from raised intracranial pressure), seizures, speech or movement disturbances, and personality and cognitive changes. Symptoms usually progress over weeks.
Diagnosis
Contrast-enhanced magnetic resonance imaging (MRI) is the first-line study; it typically shows a ring-enhancing mass with central necrosis surrounded by edema. Definitive diagnosis is made by pathological and molecular analysis (e.g., IDH status, MGMT methylation) of tissue obtained at surgery or biopsy.
Treatment
The standard approach is maximal safe surgical resection followed by concurrent radiotherapy and temozolomide chemotherapy (the Stupp protocol). Treatment is individualized according to tumor location and patient condition. Care is planned by a multidisciplinary team (neurosurgery, radiation oncology, medical oncology).
Prognosis
Glioblastoma is aggressive and, despite current treatment, prognosis remains limited; molecular features such as MGMT promoter methylation may influence treatment response. Treatment often aims to control the disease and preserve quality of life. Outcomes vary from patient to patient and no outcome is guaranteed.
References
- Stupp R, et al. Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. N Engl J Med. 2005.
- Louis DN, et al. The 2021 WHO Classification of Tumors of the Central Nervous System. Neuro Oncol. 2021.
- StatPearls — Glioblastoma Multiforme. NCBI Bookshelf.
This article is for general information and does not replace a medical examination. Diagnosis and treatment decisions are individual.