Case contributed by A.Prof Frank Gaillard


Headache and seizure.

Patient Data

Age: 25 years

Sagittal and coronal pre and post contrast CT demonstrate a large partially calcified left frontal lobe mass. 


Left frontal lobe intra-axial lesion is demonstrated that involves cortex as well as subcortical white matter, expanding both, with moderate regional mass effect, compressing the frontal horns of the lateral ventricles and effacing regional sulci.

Scattered within the tumor are small nodular areas of contrast enhancement, particularly at the medial aspect and at the rim, with no discrete mass enhancing mass demonstrated. The rim of the tumor also demonstrates restricted diffusion (ADC 600-800 x 10^-6 mm^2/s).

There are areas of susceptibility artefact within and surrounding the tumor, some representing products of blood degradation. A small amount of calcification is probably also present within the lesion. The contrast enhancing components show increased rCBV, again more noticeably at the medial aspect.

MRS through the enhancing components also shows increased choline, increased lipid/lactate and slightly reduced NAA.

There are also multiple prominent vessels seen traversing the tumor, felt to be sulcal. 


The patient went on to have a resection. 


Paraffin sections show a densely cellular glial tumor. Tumor cells have oligodendroglial morphological features - round and oval nuclei with vesicular chromatin and perinuclear clearing with tumor cells arranged in lobules delimited by thin-walled capillaries. A very occasional mitotic figure is identified. There is no multilayering of atypical cells around vessel lumena and no necrosis is identified. There is patchy tumor calcification. Tumor extends through the full thickness of cerebral cortex, breaches the pia-arachnoid and extends into the sub-arachnoid space.


  • GFAP negative in tumor cells
  • NogoA positive
  • IDH-1 R132H positive (mutated)
  • ATRX positive (not mutated)
  • P53 positive
  • P16 CDK N2A positive
  • Topoisomerase labeling index: Approximately 10%

FISH for chromosome 1p/19q deletion.

Chromosome 1. Mean copies 1p per cell: 1.40 Mean copies 1q per cell: 2.17 1p/1q ratio: 0.65 Interpretation: 1p loss detected by FISH

Chromosome 19 Mean copies 19q per cell: 1.13 Mean copies 19p per cell: 1.88 19q/19p ratio: 0.60 Interpretation: 19q loss detected by FISH

FINAL DIAGNOSIS: oligodendroglioma IDH mutant chromosome 1p/19q co-deleted (WHO Grade II)

Case Discussion

Typical appearances of an oligodendroglioma based on histology and molecular profiling. 

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Case information

rID: 65587
Published: 22nd Jun 2019
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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