Glioblastoma NOS (pseudoprogression)

Case contributed by A.Prof Frank Gaillard

Patient Data

Age: Adult

Single post contrast T1 C+ image demonstrates a large heterogeneously enhancing mass in the right temporal lobe. 

The patient went on to have a craniotomy. 


MICROSCOPIC DESCRIPTION: Paraffin sections show a densely hypercellular glial tumour. This consists predominantly of astrocytic cells with marked nuclear and cellular pleomorphism. Markedly pleomorphic multinucleated tumour cells are noted in several areas. There are frequent mitotic figures with some atypical mitoses noted and there is prominent vascular endothelial cell hyperplasia. Areas of both pallisaded and confluent necrosis are also identified. Some of these incorporate thin-walled necrotic and thrombosed blood vessels. A minor oligodendroglial component is identified.

FINAL DIAGNOSIS:  glioblastoma

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


Following resection, the patient undertook a course of combined chemo and radiotherapy. 


Day 1 post op

Day 1 post op scan demonstrates complete resection of enhancing tumor. 


4 months later (1 month after finishing chemoradiotherapy)

Enhancing nodule posterior to the resection cavity has reduced CBV and a flat MRS trace. 


Follow up MRI scans

Selected images from follow scans demonstrate gradual reduction in enhancement with no evidence of progression. Features are those of pseudoprogression. 

Case Discussion

Tumor pseudoprogression corresponds to an increase of lesion area related to treatment simulating a progressive disease. The term is largely used in brain tumors imaging follow-up, especially for high grade gliomas, like in this case, when observed after chemotherapy and radiotherapy treatment or after just radiotherapy treatment. 

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Case information

rID: 38496
Published: 22nd Jul 2015
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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