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Last Updated: March 27, 2020

Figure 1: This oligodendroglioma has internal coarse calcification on CT (top row left) that is very typical of this tumor. Coronal FLAIR (top row right) demonstrates typical fairly circumscribed permeative involvement of cortex and adjacent white matter. The mild hyperperfusion on this CBV image (bottom) is also seen fairly often in oligodendroglioma due to the pathologic feature of “chicken-wire” vascularity.

Basic Description

  • Slow-growing and infiltrating cortical/subcortical glial tumor


  • WHO grade II
  • Anaplastic oligodendrogliomas (AO) are WHO 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-wildtype and 1p/19q-codeleted

Clinical Features

  • Typically occur during 5th to 6th decades
  • Slight male gender predilection
  • Presenting symptoms: seizures, headaches, and focal neurologic deficits
  • Median survival 10 years
    • Better prognosis than astrocytomas of same WHO grade

Imaging Features

  • General
    • Well-marginated but infiltrating cortical/subcortical mass
    • Usually supratentorial location
      • Frontal lobe >> temporal, parietal, and occipital lobes
    • Cystic and solid tumor components may be present in variable degrees
    • Calcification present in 40-80%
    • Usually minimal to no peritumoral edema
    • Oligoastrocytomas are less common but have a very similar appearance to oligodendrogliomas of the same WHO grade
  • CT

    • Hypo- 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
  • MRI

    • T1WI: heterogeneous, hypo- 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
    • MR Spectroscopy (MRS)/MR perfusion: elevated choline, decreased NAA, absent lipid/lactate peak (unlike anaplastic oligodendroglioma); unique characteristic of elevated relative cerebral blood volume (rCBV) in spite of lower grade due to pathologic feature of “chicken-wire vascularity”

Imaging Recommendations

  • 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

DOI: https://doi.org/10.18791/nsatlas.v1.03.01.30


Koeller KK, Rushing EJ. From the archives of the AFIP: Oligodendroglioma and its variants: radiologic-pathologic correlation. Radiographics. 2005;25: 1669-1688.

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, Cavenee WK, Burger PC, Jouvet A, et al. The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol 2007;114:547.

Osborn AG, Salzman KL, Jhaveri MD. Diagnostic imaging (3rd ed). Philadelphia, PA: Elsevier, 2016.

Perry JR. Oligodendrogliomas: clinical and genetic correlations. Curr Opin Neurol. 2001;14: 705-710.

Xu M, 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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