Radiological findings in gliosarcoma. A single institution experience

Clinicopathological and Neuroimaging Features of Primary Gliosarcoma: A Case Series and Review of Literature

BACKGROUND

Gliosarcoma (GS) is a rare primary high-grade brain neoplasm with a poor prognosis and challenging surgical resection. Although it is now considered a morphologic variant of IDH-wildtype glioblastoma (World Health Organization Classification of Tumours 2021), GS may display peculiarities that hamper both surgical and oncological management.

METHODS

In this retrospective study, we searched our registry for histologically confirmed GS patients between 2006 and 2020. Cases were reviewed for clinical information, pathologic characteristics, imaging findings, management, and outcome.

RESULTS

21 patients with histologically confirmed GS were identified with a median age of 62 years. Twelve were men and 9 women. The temporal lobe was the most common location (9 patients, 42.9%). Nineteen patients underwent surgical resection, and only 4 (19%) demonstrated gross total resection on postsurgical MRI, with an overall median survival of 7 months (range, 0.5-37). Diagnostic MRI demonstrated heterogenous lesions with necrotic-cystic areas and a ring-enhancement pattern. Only 1 case of extracranial extension was seen in our sample, and no patient showed distant metastases.

CONCLUSIONS

The rarity of primary GS and the absence of specific therapeutic guidelines represent a significant clinical challenge. Our study provides a comprehensive analysis of clinical and neuroimaging characteristics in a real-world patient cohort and compares our findings with the available literature.

Do gliosarcomas have distinct imaging features on routine MRI?

PURPOSE

The aim of this study was the development and external validation of a logistic regression model to differentiate gliosarcoma (GSC) and glioblastoma multiforme (GBM) on standard MR imaging.

METHODS

A univariate and multivariate analysis was carried out of a logistic regression model to discriminate patients histologically diagnosed with primary GSC and an age and sex-matched group of patients with primary GBM on presurgical MRI with external validation.

RESULTS

In total, 56 patients with GSC and 56 patients with GBM were included. Evidence of haemorrhage suggested the diagnosis of GSC, whereas cystic components and pial as well as ependymal invasion were more commonly observed in GBM patients. The logistic regression model yielded a mean area under the curve (AUC) of 0.919 on the training dataset and of 0.746 on the validation dataset. The accuracy in the validation dataset was 0.67 with a sensitivity of 0.85 and a specificity of 0.5.

CONCLUSIONS

Although some imaging criteria suggest the diagnosis of GSC or GBM, differentiation between these two tumour entities on standard MRI alone is not feasible.

Gliosarcoma in patients under 20 years of age. A clinicopathologic study of 11 cases and detailed review of the literature

BACKGROUND

Gliosarcoma is a rare variant of IDH- wild type glioblastoma with both glial and mesenchymal differentiation. It accounts for approximately 2% of glioblastomas and has a poor prognosis similar to that of classic glioblastoma. It is seen mostly between 40 and 60 years of age with a mean age over 50 years. Pediatric gliosarcoma is even rarer than gliosarcoma in adults. We describe the clinicopathological features of gliosarcoma in patients under 20 years of age and determine whether there are significant differences from gliosarcoma in adults. We also present detailed review of published literature on pediatric gliosarcoma.

METHODS

Slides of gliosarcomas in patients under 20 years of age were reviewed. Clinicopathological features were noted in detail and follow up was obtained.

RESULTS

Eleven cases of gliosarcoma were reported in patients under 20 years of age. Ages ranged from three to 19 years (mean age 13 years). Frontal, parietal and temporal lobes were the commonest locations. Mean and median tumor size was six and five cm respectively. All 11 cases demonstrated the classic biphasic pattern. In 10 cases, glial component was astrocytic and was highlighted on GFAP. Sarcomatous component in most cases resembled fibrosarcoma and was high grade in 72.7%. Glial areas were reticulin poor while sarcomatous areas were reticulin rich. In over 45% cases, bizarre tumor giant cells were seen in the sarcomatous areas. In 1 case, sarcomatous areas showed extensive bone and cartilage formation. Other histologic features included hyalinized blood vessels, hemorrhage, infarction, gemistocytic cells, rhabdoid cells etc. Follow up was available in nine patients, five received chemoradiation post resection while three received radiotherapy only. Prognosis was dismal and eight patients died within one to 14 months following resection.

CONCLUSIONS

Gliosarcomas in patients under 20 comprised 13% of all gliosarcomas reported during the study period. Frequency and mean age were higher compared to other published reports. Pathological features were similar to those described in literature. Clinicopathological features and prognosis of pediatric gliosarcomas were similar to adult gliosarcomas.

The clinical, radiological, and immunohistochemical characteristics and outcomes of primary intracranial gliosarcoma: a retrospective single-centre study

Primary intracranial gliosarcoma is a rare malignant brain tumour, and the most effective treatment for gliosarcoma remains unclear. This study aimed to identify risk factors for progression-free survival (PFS) and overall survival (OS) in these cases. This retrospective single-centre study evaluated 103 patients (median age, 51 years; 67 men [65%]) with primary intracranial gliosarcoma between 2006 and 2017. Treatments included surgery (GTR, 63 patients; STR, 39 patients; biopsy, 1 patient), radiotherapy (adjuvant, 76 patients; exclusive treatment, 1 patient), and chemotherapy (adjuvant temozolomide, 52 patients; adjuvant nimustine/teniposide, 19 patients; adjuvant bevacizumab, 1 patient; exclusive nimustine/teniposide treatment, 1 patient). The median OS was 13.3 months, and the median PFS was 9.1 months. In the multivariate analyses, the poor prognostic factors were ependymal lining enhancement of the lateral ventricle (PFS, HR 2.406, p = 0.005; OS, HR 2.946, p = 0.009) and enhancement in the motor functional cortex (PFS, HR 2.892, p = 0.002; OS, HR 2.639, p = 0.009). Good OS was predicted by adjuvant radiotherapy alone (HR 0.071, p < 0.001), adjuvant temozolomide-based chemotherapy alone (HR 0.063, p = 0.005), adjuvant temozolomide-based chemotherapy with concurrent radiotherapy (HR 0.056, p < 0.001), and salvage surgery at recurrence (HR 0.449, p = 0.031). The present study revealed that, in patients with primary intracranial gliosarcoma, enhancement in the functional motor cortex and ependymal lining enhancement of the lateral ventricle were both poor prognostic factors. Survival was optimized in cases treated using maximal safe resection followed by adjuvant temozolomide-based chemotherapy with concurrent radiotherapy. Furthermore, salvage surgery provided meaningful therapeutic benefits for recurrent gliosarcoma.

Gliosarcomas: magnetic resonance imaging findings

BACKGROUND

Central nervous system (CNS) gliosarcoma (GSM) is a rare primary neoplasm characterized by the presence of glial and sarcomatous components.

OBJECTIVE

In this report, we describe the clinical and neuroimaging aspects of three cases of GSM and correlate these aspects with pathological findings. We also provide a brief review of relevant literature.

METHODS

Three patients were evaluated with magnetic resonance imaging (MRI), and biopsies confirmed the diagnosis of primary GSM, without previous radiotherapy.

RESULTS

The analysis of conventional sequences (T1, T1 after contrast injection, T2, Fluid attenuation inversion recovery, SWI and DWI/ADC map) and advanced (proton 1H MR spectroscopy and perfusion) revealed an irregular, necrotic aspect of the lesion, peritumoral edema/infiltration and isointensity of the solid component on a T2-weighted image. These features were associated with irregular and peripheral contrast enhancement, lipid and lactate peaks, increased choline and creatine levels in proton spectroscopy, increased relative cerebral blood volume (rCBV) in perfusion, multifocality and drop metastasis in one of the cases.

CONCLUSION

These findings are discussed in relation to the general characteristics of GSM reported in the literature.