Fact-sheet: Oligodendroglioma
Updated on 03/31/2020 at 8:50 AM
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Definition
Belongs to the diffuse glial tumors.
5 to 20% of gliomas and 2 to 5% of primary central nervous system tumors.
Often encountered in adults:
- between 35 and 55 years, peak incidence between 40 and 45 years with a slight male predominance
- supratentorial tumor in the great majority: frontal > temporal > parietal > occipital
- develops at the gray-white matter junction.
Clinical features
- Seizures due to cortical involvement
- Headaches
CT
- Peripheral and cortical lesion
- Generally hypodense, sometimes of mixed density
- Calcifications: possible, suggestive if gyriform
- Enhancement: absent or mild (50% of cases)
MRI
- Fairly well-defined
- Hypointense relative to gray matter on T1
- Hyperintense on T2 FLAIR and heterogeneous
- Generally no edema
- Calcifications appearing hypointense on T2*
- Generally no enhancement, or mild
- MR spectroscopy: mild elevation of choline and decrease in NAA
- Caution: on perfusion imaging, an elevated rCBV does not necessarily indicate high grade.
Management
- Complete surgical resection
- and adjuvant radiochemotherapy possible
Classification
Oligodendrogliomas in the new 2016 WHO classification of brain tumors show 1p19q codeletion and are IDH-mutant.
They are grade II or grade III.
Differential diagnosis
- Diffuse astrocytomas, neurocytomas, DNETs, and gangliogliomas.