Astrocytoma
Astrocytoma is the most common group of glial tumors, arising from the brain's supporting cells, the astrocytes. The 2021 World Health Organization (WHO) classification redefined astrocytomas by IDH mutation status, treating IDH-mutant astrocytoma as a distinct disease from IDH-wildtype glioblastoma.
Última actualización: 2026-06-06
Definition
Astrocytoma is a primary brain tumor that develops from astrocytes, the supporting cells of the brain. It accounts for roughly one third of all primary brain tumors and is the most common type of glial tumor. It can occur at any age; pilocytic astrocytoma predominates in children, while diffuse infiltrative astrocytomas predominate in adults.
Epidemiology
The incidence of astrocytic tumors is about 4.8 per 100,000 person-years. Diffuse astrocytomas typically peak in young-to-middle-aged adults (35-45 years), while pilocytic astrocytoma peaks in children (5-15 years). They are slightly more common in men than women. Most cases have no identifiable risk factor; ionizing radiation and certain hereditary syndromes (Li-Fraumeni, NF1, Turcot) are associated with increased risk.
Symptoms
Symptoms vary with tumor location and grade. Epileptic seizures are often the presenting complaint, particularly in low-grade cortical tumors. Other features include headache from raised intracranial pressure, personality and behavioral changes, memory and concentration difficulties, speech disturbance (aphasia), and location-dependent limb weakness or incoordination.
Diagnosis
MRI is the principal diagnostic tool, showing an infiltrative, hyperintense lesion on T2 and FLAIR sequences. Advanced MRI techniques (perfusion, spectroscopy, diffusion) and amino-acid PET help assess tumor grade and active tumor tissue. Definitive diagnosis is made by pathological and molecular examination of tissue obtained by stereotactic biopsy or surgical resection. Markers such as IDH mutation, CDKN2A/B status, ATRX and TP53 are critical for diagnosis, grading and prognosis.
Classification and Grading (2021 WHO CNS5)
The 2021 WHO classification redefined adult diffuse gliomas by IDH status. IDH-mutant astrocytoma is now considered a single tumor type and graded 2, 3 or 4; the term 'anaplastic' has been removed. In the presence of microvascular proliferation, necrosis or homozygous CDKN2A/B deletion, the tumor is considered grade 4 regardless of histology. IDH-mutant astrocytomas carry a markedly better prognosis than IDH-wildtype glioblastoma.
Treatment Options
Treatment is individualized according to grade, IDH status, molecular profile, tumor location and the patient's condition. The first step is usually the widest safe surgical resection; modern techniques such as neuronavigation, intraoperative MRI, 5-ALA fluorescence and awake craniotomy increase resection while preserving function. For low-grade IDH-mutant tumors, options after surgery include close surveillance, the brain-penetrant IDH inhibitor vorasidenib (approved for certain grade 2 cases after surgery), and radiotherapy with chemotherapy when needed. Higher-grade cases add radiotherapy and chemotherapy (temozolomide or PCV).
Prognosis
One of the strongest determinants of prognosis is IDH mutation status. Survival in IDH-mutant astrocytomas is markedly longer than in IDH-wildtype glioblastoma and varies by grade. Because low-grade tumors may transform to higher grade over time, close MRI follow-up is important. Care is delivered by a multidisciplinary team; outcomes vary individually and no outcome can be guaranteed.
Referencias
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:660.
- Osborn AG, Hedlund GL, Salzman KL. Osborn's Brain: Imaging, Pathology, and Anatomy. 2nd ed. Elsevier; 2018:509.
- Louis DN, et al. The 2021 WHO Classification of Tumors of the Central Nervous System. Neuro Oncol. 2021.
- Weller M, et al. EANO guidelines on the diagnosis and treatment of diffuse gliomas of adulthood. Nat Rev Clin Oncol. 2021.
Este artículo es informativo y no sustituye un examen médico. Las decisiones de diagnóstico y tratamiento son individuales.