Glioblastoma - exophytic into ventricle

Case contributed by A.Prof Frank Gaillard


Increasing headaches over a number of weeks. This patient initially had a CT scan (not shown) which demonstrated a left sided lesion. MRI was performed to further characterise it.

Patient Data

Age: 40 years
Gender: Male

MRI of the brain

Modality: MRI

MRI with contrast demonstrates a large heterogeneous mass arising form the left thalamus and growing exophytically into the the lateral ventricle. It is associated with dilatation of both lateral ventricles, in keeping with obstruction of their out-flow at the foramen of Munro. Areas of the mass are intrinsically high on T1 weighted imaging and show signal drop out on T2 weighted sequences, suggestive of haemorrhage, and on DWI the mass is quite high signal (low on ADC - not shown) consistent with a degree of restricted diffusion, suggesting high cellularity. Following contrast administration the mass heterogeneously enhances.

In the posterior fossa, particularly on the ventral surface of the brainstem is leptomeningeal enhancement, likely representing CSF seeding. 

Annotated images

Modality: MRI

The large mass is comprised of a haemorrhagic component (yellow dotted line) and a solid enhancing cellular component (blue dotted line). 

Extensive leptomeningeal disease is also present (green arrows). 

This patient went on to have a craniotomy and debulking of the tumour. 


MICROSCOPIC DESCRIPTION: Paraffin sections confirm the  frozen section diagnosis.  This is a cellular astrocytic tumour showing moderate to marked nuclear pleomorphism, confluent  tumour   necrosis,  and  vascular   thrombosis.    Microvascular proliferation  is  not a well  developed   feature.   There are  occasional mitotic    figures,   and   apoptoses   are   relatively    frequent.    An oligodendroglial component is not identified.  A low grade component is not identified. 

FINAL DIAGNOSIS: Left thalamic astrocytoma WHO grade 4 (glioblastoma).

Case Discussion

This case elegantly demonstrates how intraparenchymal lesions can grow exophytically into the ventricles mimicking intraventricular masses. The key observation is the degree of involvement of the thalamus and adjacent white matter. Compare this case with a similar appearing case of central neurocytoma.

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Case Information

rID: 14249
Case created: 10th Jul 2011
Last edited: 19th Sep 2016
Inclusion in quiz mode: Included

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