Diffuse astrocytoma NOS ("protoplasmic")

Case contributed by Dr Bruno Di Muzio



Patient Data

Age: 50 years

CT Brain

There is a bad-defined expansile lesion in the left frontal lobe with signs of cortical involvement and local vasogenic oedema. Further investigation with MRI is mandatory for a better characterisation of this finding. 

Ventricular system and cisternal spaces appear normal.

There is no shift of the midline structures.


MRI Brain

There is a left frontal lobe tumour characterised by focal cortical involvement in the inferior frontal gyrus associated with an extensive area of high T2 signal in the adjacent white matter which slightly and partially suppress on FLAIR , extending partially to the adjacent insula and middle frontal gyrus. No contrast enhancement is observed. Mild areas of restricted diffusion are observed within the tumour. 

Ventricular system and cisternal spaces appear normal. There is no shift of the midline structures. The visualized orbits, paranasal sinuses and calvarium appear unremarkable.

Case Discussion

This case represents a left frontal solid tumour involving the cortex and with features suggesting a low-grade glioma. The tumour was resected and confirmed as a protoplasmic astrocytoma

Note: Until recently, protoplasmic astrocytomas were classified as a subtype low-grade astrocytoma, however, in the latest (2016) update to WHO classification of CNS tumours, protoplasmic astrocytomas no longer exists as a distinct entity, but rather are considered as a pattern of certain gliomas, requiring IDH +/- 1p19q status for classification. 

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 diffuse astrocytoma NOS.


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Case information

rID: 38789
Case created: 4th Aug 2015
Last edited: 22nd Jun 2017
Tag: rmh
Inclusion in quiz mode: Included

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