Gliosarcoma: a clinical and radiological analysis of 48 cases

Objectives: To retrospectively review the radiological and clinicopathological features of gliosarcoma (GSM) and differentiate it from glioblastoma multiforme (GBM).

Methods: The clinicopathological data and imaging findings (including VASARI analysis) of 48 surgically and pathologically confirmed GSM patients (group 1) were reviewed in detail, and were compared with that of other glioblastoma (GBM) cases in our hospital (group 2).

Results: There were 28 men and 20 women GSM patients with a median age of 52.5 years (range, 24-80 years) in this study. Haemorrhage (n = 21), a salt-and-pepper sign on T2-weighted images (n = 36), unevenly thickened wall (n = 36) even appearing as a paliform pattern (n = 32), an intra-tumoural large feeding artery (n = 32) and an eccentric cystic portion (ECP) (n = 19) were more commonly observed in the GSM group than in GBM patients. Based on our experience, GSM can be divided into four subtypes according to magnetic resonance imaging (MRI) features. When compared to GBM (group 2), there were more patients designated with type III lesions (having very unevenly thickened walls) and IV (solid) lesions among the GSM cases (group 1). On univariate prognostic analysis, adjuvant therapy (radiotherapy, chemotherapy, and radiochemotherapy) and existence of an eccentric cyst region were prognostic factors. However, Cox's regression model showed only adjuvant therapy as a prognostic factor for GSM.

Conclusions: When compared to GBM, certain imaging features are more likely to occur in GSM, which may help raise the possibility of this disease. All GSM patients are recommended to receive adjuvant therapy to achieve a better prognosis with radiotherapy, chemotherapy or radiochemotherapy all as options.

Key points: • Diagnosis of gliosarcoma can be suggested preoperatively by imaging. • Gliosarcoma can be divided into four subtypes based on MRI. • Paliform pattern and ECP tend to present in gliosarcoma more than GBM. • The cystic subtype of gliosarcoma may predict a more dismal prognosis. • All gliosarcoma patients should receive adjuvant therapy to achieve better prognosis.