NCI Definition: A well-differentiated (WHO grade II), diffusely infiltrating neuroglial tumor, typically located in the cerebral hemispheres. It is composed predominantly of cells which morphologically resemble oligodendroglia. The neoplastic cells have rounded homogeneous nuclei and, on paraffin sections, a swollen, clear cytoplasm ('honeycomb' appearance). (Adapted from WHO) [1]

Oligodendrogliomas most frequently harbor alterations in IDH1, PIK3CA, NOTCH1, IDH2, and PIK3R1 [2].

Most Commonly Altered Genes in Oligodendroglioma

IDH1 Mutation, IDH1 Codon 132 Missense, IDH1 R132H, PIK3CA Mutation, and NOTCH1 Mutation are the most common alterations in oligodendroglioma [2].

Top Alterations in Oligodendroglioma

Significant Genes in Oligodendroglioma

IDH1 +

IDH2 +

Disease Details

OLIGODENDROGLIOMA, UNDETERMINED, Well Differentiated Oligodendroglial Tumor, WHO Grade II Oligodendroglial Neoplasm, Oligodendroglioma, NOS, WHO Grade II Oligodendroglial Tumor, Well Differentiated Oligodendroglioma
WHO Grade II Glioma
Childhood Oligodendroglioma, Adult Oligodendroglioma, Brain Oligodendroglioma, and Anaplastic Oligodendroglioma
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OncoTree Code


1. National Cancer Institute. NCI Thesaurus Version 18.11d. https://ncit.nci.nih.gov/ncitbrowser/ [2018-08-28]. [2018-09-21].

2. The AACR Project GENIE Consortium. AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discovery. 2017;7(8):818-831. Dataset Version 6. This dataset does not represent the totality of the genetic landscape; see paper for more information.

3. All assertions and clinical trial landscape data are curated from primary sources. You can read more about the curation process here.