Glioblastoma NOS

Case contributed by Dr Sara Wein



Patient Data

Age: 60 years
Gender: Female

There is a large intracranial mass lesion centered on the right frontal lobe measuring approximately 45 mm in maximum diameter with a large amount of surrounding vasogenic edema. The lesion leads to a mass effect with effacement of the frontal horn of the right lateral ventricle and is approximately 13 mm of right-to-left subfalcine herniation and midline shift. No other parenchymal lesions. No acute intra orextra-axial hemorrhage.


Multiple peripherally enhancing lesions with central hypodensity in the right frontal lobe. Significant surrounding vasogenic edema. There is effacement of the frontal horn of the right lateral ventricle, subfalcine herniation and right-to-left midline shift of 13mm at the level of the septum pellucidum. No tonsillar or uncal herniation. The left ventricle is not dilated

No other areas of abnormal contrast enhancement. Mastoid air cells and paranasal sinuses are clear.


Multiple peripherally enhancing lesions in the right frontal lobe resulting in significant mass effect. In the setting of fever, the findings are suspicious for cerebral abscesses. The differential includes metastatic lesions and a primary brain tumor. MRI is recommended to further evaluate.


Within the right frontal lobe, there is a cluster of multiple adjacent peripherally enhancing lesions. This is surrounded by a large amount of FLAIR hyperintensity which extends across the genu of the corpus callosum into the left frontal lobe and involves the right internal capsule, lentiform nucleus and thalamus. The signal abnormality and enhancement involve the right frontal cortex as well as white matter. Within the right frontal lobe just superior to the Sylvian fissure, there is a separate 10 mm nodule of enhancement.

There is a large amount of mass effect, characterized by right frontal cortical sulcal effacement, compression of the right lateral and third ventricles and 11 mm of right to left shift and subfalcine herniation.

There is a slight dilatation of the left lateral ventricle consistent with early hydrocephalus. Within the right frontal lobe, there is mild diffusion restriction.


Findings are strongly favored to represent a high-grade glioma.

Case Discussion

The patient went on to have surgery. 


MICROSCOPIC FEATURES: Paraffin sections show extensive replacement of white matter by a densely hypercellular glial tumor. This is composed predominantly of fibrillary and gemistocytic astrocytes which show moderate nuclear and cellular pleomorphism. In addition, there is a minor oligodendroglial component. Frequent mitotic figures are identified. There is prominent microvascular proliferation with multi-layering of atypical cell around vascular lumens. Several areas of palisaded necrosis are also noted. These incorporate thin-walled necrotic and thrombosed blood vessels. Tumor extensively involves cerebral cortex and there is prominent peri-neuronal, perivascular and subpial secondary structuring. The features are of glioblastoma with a minor oligodendroglioma component (WHO Grade IV).

FINAL DIAGNOSIS: glioblastoma with a minor oligodendroglioma component


Note: IDH mutation status is not provided in this case and according to the current (2016) WHO classification of CNS tumors, this tumor would, therefore, be designated as a glioblastoma NOS

Note: The diagnosis of glioblastoma is actually not entirely established in this case as the IDH wild-type status has not been assessed. Although in this age group it is likely to reflect an IDH wild-type glioblastoma, it is possible that this is a IDH mutant glioblastoma (secondary glioblastoma). If an IDH mutation were to be found, then 1p19q codeletion status would also need to be established

This is important from a classification and prognosis point of view as if an IDH mutation was found and 1p19q was co-deleted then this tumor would actually represent an anaplastic oligodendroglioma and not a glioblastoma.

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Case information

rID: 33414
Published: 13th Jan 2015
Last edited: 2nd Feb 2020
Inclusion in quiz mode: Included

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