Anaplastic oligodendroglioma

Case contributed by Assoc Prof Frank Gaillard



Patient Data

Age: 60 years

A large right frontal mass with calcification and enhancement is present. Large portions of the mass involve the cortex. Features are those of an oligodendroglial tumor. 


The right-sided mass is heavily calcified with some patchy areas on enhancement seen at the margins. 

Case Discussion

The patient went on to have surgery confirming the diagnosis of an anaplastic oligodendroglioma. It is important to note that according to the current (2016) WHO classification of CNS tumors, a tumor that has been shown to be an oligodendroglioma (IDH mutant, 1p19q co-deleted) the presence of necrosis and microvascular proliferation does not change the diagnosis to GBM. The most an oligodendroglioma can ever aspire to become anaplastic. 


MICROSCOPIC DESCRIPTION: Sections show a moderately cellular tumor composed of moderately pleomorphic cells containing round to oval, hyperchromatic, vesicular nuclei with inconspicuous nucleoli and prominent perinuclear clearing. Tumor cells are arranged in diffuse sheets intersected by thin-walled "chicken-wire" capillaries. Prominent microcalcification is present. Occasional mitotic figures are identified (up to 2/10hpf). Focal pallisaded tumor necrosis and microvascular proliferation are seen.


  • GFAP Negative
  • Nogo A Positive
  • Nestin Positive (low)
  • IDH-1 R132H Positive (mutated)
  • ATRX Positive (non-mutated)
  • MGMT Negative (likely methylated)
  • p53 Negative
  • p16 Positive
  • Topoisomerase labeling index: Approximately 8%.

FISH for chromosome 1p/19q co-deletion: 

  • 1p36 deletion detected
  • 19q13.3 deletion detected
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Case information

rID: 55579
Published: 20th Feb 2018
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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