Synopsis
Recognise common glioma presentations and explain how contemporary integrated diagnosis combines histology with molecular alterations while keeping adult-type and paediatric-type diffuse glioma categories distinct.
- Glioma is a broad family of CNS tumours; presentation reflects location and growth rate, while definitive type and grade require integrated pathological assessment. Glioneuronal tumours are a distinct WHO category, not a glioma subtype.
- Current WHO fifth-edition taxonomy separates adult-type diffuse gliomas into astrocytoma, IDH-mutant; oligodendroglioma, IDH-mutant and 1p/19q-codeleted; and glioblastoma, IDH-wildtype.
- Paediatric-type diffuse low-grade and high-grade gliomas are separate molecular families; patient age alone does not justify assigning an adult treatment pathway.
Key red flags
First focal seizure, prolonged seizure, clustered seizures, persistent postictal deficit or failure to regain baseline consciousness.
Progressive focal weakness, dysphasia, visual-field loss, cognitive or personality change, or gait dysfunction over days to weeks.
Headache with repeated vomiting, papilloedema, drowsiness or new cranial-nerve findings suggesting raised pressure or obstructive hydrocephalus.
Rapid worsening in a person with a known glioma, which may reflect oedema, haemorrhage, treatment effect, hydrocephalus, seizure or tumour progression.
A child with newly abnormal central neurological function or an under-12 red-flag headache pattern requires a paediatric pathway rather than direct transfer of adult diffuse-glioma guidance.
Map weakness, sensory loss, field defect, dysphasia, neglect, apraxia or ataxia and document progression. Sudden onset still requires a vascular and haemorrhagic differential, including bleeding into tumour.
Progressive headache, vomiting, papilloedema, sixth-nerve palsy or drowsiness may reflect oedema, tumour volume or hydrocephalus. Pupil change and declining consciousness require emergency action before molecular work-up.
Reasoning priorities
Define tumour location, infiltration, enhancement, diffusion, oedema and relation to eloquent cortex and CSF pathways.
NICE NG99 defines the standard series as T2, FLAIR, DWI and T1 pre- and post-contrast volume imaging. Enhancement can support suspicion of higher-grade biology but neither enhancement nor its absence supplies an integrated diagnosis.
Worked reasoning
An adult recovers from a first focal seizure and MRI shows a diffuse non-enhancing frontal lesion without acute mass effect.
- Confirm seizure recovery, document focal neurological and cognitive baseline, treat any ongoing seizure as an emergency and avoid inferring low grade solely from current alertness.
- Review the complete standard structural MRI with the specialist team, considering advanced imaging when sampling a potentially transformed focus would change the diagnostic plan.
- Refer at first radiological diagnosis to the neuro-oncology multidisciplinary team, which balances resection or biopsy against eloquent location, tumour extent, age, performance and the need for tissue.
- Request an integrated WHO diagnosis from representative tissue, using morphology with IDH and lineage-defining molecular tests rather than reporting “oligoastrocytoma” from mixed appearance alone.
- Verify the final entity, grade and key predictive markers at MDT, then explain the treatment and surveillance implications while acknowledging sampling and imaging uncertainty.
Histology suggests diffuse glioma but age, midline location or initial molecular tests do not fit a routine adult-type entity.