Gliosarcomas are rare, highly malignant (WHO grade IV) primary intra-axial neoplasms with both glial and mesenchymal elements. They are often considered a histological variant of glioblastoma (GBM) sharing a similar malignant course, prognosis and epidemiological pattern.
Peak presentation is around the 6th decade. There may be a slight male predilection.
The tumour is very similar to a GBM but with an added sarcomatous component (the tumour comprises of both glial and mesenchymal elements). Most lesions are primary but secondary tumours can occur in patients with previously resected GBM or cranial irradiation.
Can be very similar to GBM. There may be slight predilection towards the temporal lobes 1. They are usually broad based peripherally located lesions with possible direct dural invasion or only reactive dural thickening (dural tail) 3-7.
Gliosarcomas may be seen on CT as a sharply defined (often due to sarcomatous component 5), round or lobulated, hyperdense solid mass. It can have relatively homogeneous contrast enhancement and peritumoral oedema.
Reported signal characteristics include:
- T1: heterogeneous and hypointense mass
- T2: heterogeneous signal due hemorrhagic and necrotic components
- T1C+ (Gd): thick irregular and rim-like or ring enhancement 8
On angiography, mixed dural and pial vascular supply may be present 3. Early cortical venous drainage, irregular tumour vessels, and a prominent vascular stain with well-defined tumour margins may also be seen.
Treatment and prognosis
As with glioblastoma this tumour carries a very poor prognosis. Extracranial metastases can occur in up to 30% of cases.
General imaging differential considerations include:
- WHO classification of CNS tumours
- WHO grading of CNS tumours
- VASARI MRI feature set
- diffuse astrocytic tumours
- prognostic markers
- diffuse astrocytoma grading
- low grade astrocytoma
- anaplastic astrocytoma
- glioblastoma variant
- glioblastoma vs cerebral metastasis
- treatment response
- Stupp protocol
- glioma treatment response assessment in clinical trials
- multicentric glioblastoma
- multifocal glioblastoma
- radiation-induced gliomas
- gliomatosis cerebri (growth pattern)
- localised astrocytic tumours
- specific locations
- 1. Kozak KR, Mahadevan A, Moody JS. Adult gliosarcoma: epidemiology, natural history, and factors associated with outcome. Neuro-oncology. 2009;11 (2): 183-91. doi:10.1215/15228517-2008-076 - Free text at pubmed - Pubmed citation
- 2. Maiuri F, Stella L, Benvenuti D et-al. Cerebral gliosarcomas: correlation of computed tomographic findings, surgical aspect, pathological features, and prognosis. Neurosurgery. 1990;26 (2): 261-7. - Pubmed citation
- 3. Jack CR, Bhansali DT, Chason JL et-al. Angiographic features of gliosarcoma. AJNR Am J Neuroradiol. 8 (1): 117-22. AJNR Am J Neuroradiol (abstract) - Pubmed citation
- 4. Galanis E, Buckner JC, Dinapoli RP et-al. Clinical outcome of gliosarcoma compared with glioblastoma multiforme: North Central Cancer Treatment Group results. J. Neurosurg. 1998;89 (3): 425-30. doi:10.3171/jns.1998.89.3.0425 - Pubmed citation
- 5. Lutterbach J, Guttenberger R, Pagenstecher A. Gliosarcoma: a clinical study. Radiother Oncol. 2001;61 (1): 57-64. Radiother Oncol (link) - Pubmed citation
- 6. Lee YY, Castillo M, Nauert C et-al. Computed tomography of gliosarcoma. AJNR Am J Neuroradiol. 6 (4): 527-31. AJNR Am J Neuroradiol (abstract) - Pubmed citation
- 7. Chourmouzi D, Potsi S, Moumtzouoglou A et-al. Dural lesions mimicking meningiomas: A pictorial essay. World J Radiol. 2012;4 (3): 75-82. doi:10.4329/wjr.v4.i3.75 - Free text at pubmed - Pubmed citation
- 8. Mehmet BASMACI. Primary Gliosarcoma: Clinical and Pathological Evaluation of Four Cases. J Neurol Sci.28 (3): 402-409. J Neurol Sci (full text)