- Slow-growing and infiltrating cortical/subcortical glial tumor
- WHO grade II
- Anaplastic oligodendrogliomas are WHO grade III
- Arises from malignant transformation of mature oligodendrocytes or glial precursor cells
- Calcification and cystic degeneration common
- “Fried-egg” microscopic appearance due to rounded nuclei and clear cytoplasm
- Genetics by WHO 2016 classification: IDH mutant, ATRX wild type, and 1p/19q codeleted
- Typically occur during fifth to sixth decades of life
- Slight male gender predilection
- Presenting symptoms: seizures, headaches, and focal neurologic deficits
- Median survival, 10 years
- Better prognosis than for astrocytomas of same WHO grade
- Well-marginated but infiltrating cortical/subcortical mass
- Usually supratentorial location
- Frontal lobe >> temporal, parietal, and occipital lobes
- Cystic and solid tumor components can be present in variable degrees
- Calcification present in 40% to 80%
- Usually minimal to no peritumoral edema
- Oligoastrocytomas are less common but have an appearance very similar to that of oligodendrogliomas of the same WHO grade
- Hypodense to isodense supratentorial mass involving the cortex and subcortical white matter
- Hyperdense foci if hemorrhage or calcification is present
- Variable enhancement on contrast-enhanced CT imaging
- T1WI: heterogeneous, hypointense to isointense relative to gray matter; ±adjacent cortical involvement with expansion
- T2WI: heterogeneously hyperintense due to hemorrhage, cystic degeneration, and calcification
- FLAIR: heterogeneously hyperintense, minimal peritumoral edema
- T2*/GRE/SWI: black signal blooming secondary to calcification and/or hemosiderin deposition from blood products
- DWI: usually does not show restricted diffusion
- T1WI+C: heterogeneous enhancement; new enhancement in WHO II tumors suggests malignant degeneration to anaplastic oligodendroglioma
- MRS/MR perfusion: elevated choline, decreased NAA, absent lipid/lactate peak (unlike anaplastic oligodendroglioma); unique characteristic of elevated relative cerebral blood volume (rCBV) despite lower grade due to pathologic feature of “chicken-wire vascularity”
- MRI with contrast including T2*/GRE/SWI, CT for demonstration of calcification
For more information, please see the corresponding chapter in Radiopaedia.
Contributor: Rachel Seltman, MD
Koeller KK, Rushing EJ. From the archives of the AFIP: oligodendroglioma and its variants: radiologic-pathologic correlation. Radiographics 2005;25: 1669–1688. doi.org/10.1148/rg.256055137.
Law M, Yang S, Wang H, et al. Glioma grading: sensitivity, specificity, and predictive values of perfusion MR imaging and proton MR spectroscopic imaging compared with conventional MR imaging. AJNR Am J Neuroradiol 2003;24:1989–1998.
Louis DN, Ohgaki H, Wiestler OD, et al. The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol 2007;114:547. doi.org/10.1007/s00401-007-0243-4.
Osborn AG, Salzman KL, Jhaveri MD. Diagnostic imaging (3rd ed). Elsevier, Philadelphia, PA; 2016.
Perry JR. Oligodendrogliomas: clinical and genetic correlations. Curr Opin Neurol 2001;14:705–710. doi.org/10.1097/00019052-200112000-00005.
Xu M, See SJ, Ng WH, et al. Comparison of magnetic resonance spectroscopy and perfusion-weighted imaging in presurgical grading of oligodendroglial tumors. Neurosurgery 2005;56:919–926; discussion 926.
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