Clinicopathologic features of primary and postirradiation cerebral gliosarcoma

Primary Intracranial Gliosarcoma: Is It Really a Variant of Glioblastoma? An Update of the Clinical, Radiological, and Biomolecular Characteristics

Gliosarcomas (GS) are sporadic malignant tumors classified as a Glioblastoma (GBM) variant with IDH-wild type phenotype. It appears as a well-circumscribed lesion with a biphasic, glial, and metaplastic mesenchymal component. The current knowledge about GS comes from the limited literature. Furthermore, recent studies describe peculiar characteristics of GS, such as hypothesizing that it could be a clinical-pathological entity different from GBM. Here, we review radiological, biomolecular, and clinical data to describe the peculiar characteristics of PGS, treatment options, and outcomes in light of the most recent literature. A comprehensive literature review of PubMed and Web of Science databases was conducted for articles written in English focused on gliosarcoma until 2023. We include relevant data from a few case series and only a single meta-analysis. Recent evidence describes peculiar characteristics of PGS, suggesting that it might be a specific clinical-pathological entity different from GBM. This review facilitates our understanding of this rare malignant brain tumor. However, in the future we recommend multi-center studies and large-scale metanalyses to clarify the biomolecular pathways of PGS to develop new specific therapeutic protocols, different from conventional GBM therapy in light of the new therapeutic opportunities.

Prognostic and predictive factors of secondary gliosarcoma: A single-institution series of 18 cases combined with 89 cases from literature

Introduction

Secondary gliosarcomas (SGS) are rare malignancies that are diagnosed subsequent to pre-existing glioma. Clinical features and optimal treatment strategies for SGS have not been conclusively established. This study aimed to assess the clinicopathological features and outcomes of SGS.

Methods

We assessed the clinicopathological features and outcomes of SGS via retrospective analysis of data for SGS patients at Tangdu Hospital. Data from SGS patients in prior publications were also analyzed in accordance with PRISMA guidelines.

Results

Eighteen SGS patients who had been treated at Tangdu Hospital between 2013 and 2020 were enrolled in this study. Additional 89 eligible SGS patients were identified from 39 studies. The median age for the patients was 53 years old, and the most common location was the temporal lobe. The most common initial diagnosis was glioblastoma (GBM) (72.0%). Radiology revealed enhanced masses in 94.8% (73/77) of patients. Ten patients (10/107, 9.35%) had extracranial metastases at or after SGS diagnosis. Patients with initial diagnosis of non-GBM and who were younger than 60 years of age were significantly associated with a long duration of disease progression to SGS. After SGS diagnosis, patients with initial non-GBM diagnosis, gross total resection and chemoradiotherapy exhibited prolonged survival outcomes. Patients who had been initially diagnosed with GBM and received both chemoradiotherapy and active therapy after disease progression to SGS, had a significantly longer overall survival than patients who did not.

Conclusion

Initial diagnosis of GBM was a poor prognostic factor for SGS. Patients who underwent gross total resection and chemoradiation had better overall survival outcomes than those who did not. However, during treatment, clinicians should be cognizant of possible extracranial metastases.

Prognostic Factors of Gliosarcoma in the Real World: A Retrospective Cohort Study

Purpose

Gliosarcoma is a histopathological variant of glioblastoma, which is characterized by a biphasic growth pattern consisting of glial and sarcoma components. Owing to its scarcity, data regarding the impact of available treatments on the clinical outcomes of gliosarcoma are inadequate. The purpose of this retrospective cohort study was to analyze the prognostic factors of gliosarcoma.

Methods

By screening the clinical database of neurosurgical cases at a single center, patients with gliosarcoma diagnosed histologically from 2013 to 2021 were identified. Clinical, pathological, and molecular data were gathered founded on medical records and follow-up interviews. Prognostic factors were derived using the Cox proportional hazards model with backward stepwise regression analysis.

Results

Forty-five GSM patients were included. Median overall survival was 25.6 months (95% CI 8.0-43.1), and median relapse-free survival was 15.2 months (95% CI 9.7-20.8). In multivariable analysis, total resection (p = 0.023, HR = 0.192, 95% CI 0.046-0.797) indicated an improved prognosis. And low expression of Ki-67 (p = 0.059, HR = 2.803, 95% CI 0.963-8.162) would be likely to show statistical significance. However, there might be no statistically significant survival benefit from radiotherapy with concurrent temozolomide (n = 33, 73.3%, log-rank p = 0.99) or adjuvant temozolomide (n = 32, 71.1%, log-rank p = 0.74).

Conclusion

This single-center retrospective study with a limited cohort size has demonstrated the treatment of gross total resection and low expression of Ki-67 which are beneficial for patients with GSM, while radiotherapy or temozolomide is not.

Primary versus secondary gliosarcoma: a systematic review and meta-analysis

INTRODUCTION

Gliosarcomas are extremely rare malignant brain tumors, which can be classified as primary gliosarcoma (PGS) if the tumors arise de novo or secondary gliosarcoma (SGS) in patients who had previously been treated for glioblastoma. Given their rarity, it is unclear if PGS is clinically and genetically different from SGS. This meta-analysis aimed to investigate the clinicopathological features, prognostic survivals, and molecular profiles of these rare tumors.

METHODS

We searched PubMed and Web of Science for relevant studies. Odds ratio (OR), hazard ratio (HR), and their 95% confidence intervals (CI) were pooled using the random-effect model.

RESULTS

We included eight studies with 239 PGS and 79 SGS for meta-analyses. Compared to PGS, SGS occurred at a younger age and had lower rates of gross total resection and radiation therapy. Bevacizumab was more commonly administered in SGS. SGS patients had a significantly worse PFS (HR 0.60; 95% CI 0.40-0.89) and OS (HR 0.46; 95% CI 0.31-0.68) in comparison to PGS. The incidences of EGFR mutation, IDH mutation, and MGMT methylation were not statistically different between PGS and SGS.

CONCLUSION

Our results demonstrated that PGS and SGS had distinct clinicopathological profiles and prognoses but shared similar genetic profiles. This study facilitates our understanding of how these two malignant brain tumors behave clinically, but future studies will be required to elucidate the genetic pathways of PGS and SGS.

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.

Spinal metastasis of glioblastoma multiforme before gliosarcomatous transformation: a case report

Background

Glioblastoma multiforme (GBM) is one of the most aggressive malignant brain tumors. Intracranial GBM metastases to the spine are rarely detected clinically. Secondary gliosarcomas after treatment of primary GBM are rarely described.

Case presentation

Herein, we report the case of a 53-year-old woman who presented to our emergency room with progressive headache and weakness on the left side. Plain computed tomography and contrast magnetic resonance imaging of the brain revealed an approximately 6.8 cm × 4.5 cm right temporoparietooccipital intraaxial cystic tumor with surrounding diffuse perifocal edema that caused midline shift toward the left. Emergency craniotomy was performed to remove the tumor, and pathological examination revealed GBM. The patient received proton beam therapy, Gliadel implantation, and oral temozolomide chemotherapy as well as targeted therapy with bevacizumab. Approximately 15 months after diagnosis, she underwent surgical resection of the right temporal recurrent tumor and was newly diagnosed as having a metastatic spinal tumor. Pathologically, the right temporal and metastatic spinal tumors were gliosarcoma and GBM, respectively.

Conclusions

Concurrent spinal metastasis and gliosarcomatous transformation, which are two types of GBM complications, are rare. To our knowledge, this is the first report of a case of recurrent GBM with gliosarcoma after proton bean therapy.

Evaluating Surgical Resection Extent and Adjuvant Therapy in the Management of Gliosarcoma

Introduction: Gliosarcomas are clinically aggressive tumors, histologically distinct from glioblastoma. Data regarding the impact of extent of resection and post-operative adjuvant therapy on gliosarcoma outcomes are limited.

Methods: Patients with histologically confirmed gliosarcoma diagnosed between 1999 and 2019 were identified. Clinical, molecular, and radiographic data were assembled based on historical records. Comparisons of categorical variables used Pearson's Chi-square and Fisher's exact test while continuous values were compared using the Wilcoxon signed-rank test. Survival comparisons were assessed using Kaplan-Meier statistics and Cox regressions.

Results: Seventy-one gliosarcoma patients were identified. Secondary gliosarcoma was not associated with worse survival when compared to recurrent primary gliosarcoma (median survival 9.8 [3.8 to 21.0] months vs. 7.6 [1.0 to 35.7], p = 0.7493). On multivariable analysis, receipt of temozolomide (HR = 0.02, 95% CI 0.001–0.21) and achievement of gross total resection (GTR; HR = 0.13, 95% CI 0.02–0.77) were independently prognostic for improved progression-free survival (PFS) while only receipt of temozolomide was independently associated with extended overall survival (OS) (HR = 0.03, 95% CI 0.001–0.89). In patients receiving surgical resection followed by radiotherapy and concomitant temozolomide, achievement of GTR was significantly associated with improved PFS (median 32.97 [7.1–79.6] months vs. 5.45 [1.8–26.3], p = 0.0092) and OS (median 56.73 months [7.8–104.5] vs. 14.83 [3.8 to 29.1], p = 0.0252).

Conclusion: Multimodal therapy is associated with improved survival in gliosarcoma. Even in patients receiving aggressive post-operative multimodal management, total surgical removal of macroscopic disease remains important for optimal outcomes.

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.

Gliosarcoma case report and review of the literature

Gliosarcoma is an unusual subtype of glioblastoma multiforme. Its characteristic features are biphasic configuration, constituting a definite, separate glial and sarcomatous differentiation, on histological evaluation. Herein, we present a rare case of Gliosarcoma that had presented only once in our center in last 13 years. A 60 years old, diabetic, hypertensive male patient came to e emergency department with disturbed level of consciousness and right sided hemiplegia which was progressive over four days. On examination he was, conscious, unoriented in time, person or place, his mouth deviated to left and vitally stable. After initial evaluation, CT scan and MRI were advised. These showed a complex left parieto-occipital heterogeneous mass lesion with cystic and solid components, measuring approximately 5.2x4cm. The mass lesion was seen displacing the occipital horn anteriorly and inferiorly with probable extension into the lateral ventricular cavity. There was no associated midline shift or definite herniation. The lesion was diagnosed as highly suggestive of brain tumor with a differential diagnosis of glioblastoma multiforme or ependymoma. Blood picture revealed a rapidly increasing level of anemia. Surgical intervention comprising left parieto-occipital craniotomy and near total resection of the tumor was carried out. On histopathological and immunohistochemical evaluation the diagnosis of GS was established. A plan of a combination of adjuvant chemotherapy and radiation was formulated that was however, declined by the family. On regular follow up, the patients clinical state rapidly deteriorated with persistence of seizures and requirement of repeated blood transfusions. The patient finally passed away after eighth months.

Clinical Characteristics of Gliosarcoma and Outcomes From Standardized Treatment Relative to Conventional Glioblastoma

Background: Gliosarcoma (GS) is a rare histopathologic variant of glioblastoma (GBM) characterized by a biphasic growth pattern consisting of both glial and sarcomatous components. Reports regarding its relative prognosis compared to conventional GBM are conflicting and although GS is treated as conventional GBM, supporting evidence is lacking. The aim of this study was to characterize demographic trends, clinical outcomes and prognostic variables of GS patients receiving standardized therapy and compare these to conventional GBM. Methods: Six hundred and eighty GBM patients, treated with maximal safe resection followed by radiotherapy with concomitant and adjuvant temozolomide at a single institution, were retrospectively reevaluated by reviewing histopathological records and tumor tissue for identification of GS patients. Clinico-pathological- and tumor growth characteristics were obtained via assessment of medical records and imaging analysis. Kaplan-Meier survival estimates were compared with log-rank testing, while Cox-regression modeling was tested for prognostic factors in GS patients. Results: The cohort included 26 primary gliosarcoma (PGS) patients (3.8%) and 7 secondary gliosarcoma (SGS) patients (1.0%). Compared to conventional GBM tumors, PGS tumors were significantly more often MGMT-unmethylated (73.9%) and located in the temporal lobe (57.7%). GS tumors often presented dural contact, while extracranial metastasis was only found in 1 patient. No significant differences were found between PGS and conventional GBM in progression-free-survival (6.8 and 7.6 months, respectively, p = 0.105) and in overall survival (13.4 and 15.7 months, respectively, p = 0.201). Survival following recurrence was not significantly different between PGS, SGS, and GBM. Temporal tumor location and MGMT status were found associated with PGS survival (p = 0.036 and p = 0.022, respectively). Conclusion: Despite histopathological and location difference between GS and GBM tumors, the patients present similar survival outcome from standardized treatment. These findings support continued practice of radiation and temozolomide for GS patients.

Clinical implications of multiple glioblastomas: An analysis of prognostic factors and survival to distinguish from their single counterparts

PURPOSE

Glioblastoma (GBM) has the highest fatality rate among primary malignant brain tumors. GBMs with synchronous multiple foci (multiple GBMs) is rarely diagnosed in the clinical scenario. This study aims to compare the clinical characteristics between multiple and single GBMs and to identify factors associated with the survival of GBM and evaluate their effects.

METHODS

We retrospectively reviewed the medical records of patients with primary GBM in a referral medical center in Taiwan who were diagnosed between 2005 and 2016. They were identified from the cancer registry database of the center and followed from the date of diagnosis to october 2018. The primary endpoint of this study was overall survival (OS), and the independent factors for survival were identified through Cox regressions.

RESULTS

A total of 48 patients were identified, of whom 44 GBM (92%) and 4 gliosarcoma (GSM) (8%). Preoperative images showed five (10%) patients had multiple brain lesions. GSM showed a high ratio of multiple lesions (50%) than patients with GBM (5%) (p = 0.05). Those with multiple lesions had significantly worse median OS of 8.2 months compared to patients with a single lesion (16 months, p = 0.03). We found that multiple GBMs was a predictor of worse survival (hazard ratio [HR] = 3.57, 95% confidence interval [95%CI]: 1.26-10.13) after adjusting for other significant predictor of radiotherapy (HR = 0.47, 95%CI: 0.23-0.96).

CONCLUSION

Patients with multiple GBMs had worse survival compared to those with single GBM. GBM patients without post-operative radiotherapy were also a predictor of worse survival.

Prognostic factors among single primary gliosarcoma cases: A study using Surveillance, Epidemiology, and End Results data from 1973-2013

Background

Prognostic factors for single primary gliosarcoma (PGS) remain unknown.

Objective

The purpose of our study was to examine patient, tumor, and treatment characteristics as potential predictors of survival using Surveillance, Epidemiology, and End Results (SEER) program data (1973‐2013).

Methods

The patients of single PGS were selected based on the exclusion criteria from SEER. Kaplan‐Meier survival analysis, log‐rank test and Cox proportional hazards models were used to analyze all the data.

Results

Single PGS has an apparent popularity for the temporal lobe (35.2%, hazard ratio [HR] = 0.440, 95%CI = 0.251‐0.770) and frontal lobe (20.9%, HR = 0.408, 95%CI = 0.231‐0.720) which could achieve a better survival rate than cerebrum (P = .034). The mean age at diagnosis was 60.07 ± 14.161. The overall 6‐month, 1‐year, 2‐year, and 5‐year survival was 55.40%, 29.58%, 10.01%, and 2.73%. Age at diagnosis was proved to be a significant predictor of overall survival (OS) (P < .001). There is no significant difference in race, marital status, or grade. Patients' tumor size which is located in 41‐60 mm (P = .047, HR = 1.468, 95%CI = 1.004‐2.147) and >60 mm (P= .003, HR = 1.899, 95%CI = 1.244‐2.901) showed a higher risk of death. Surgery played a critical role in OS (P < .001). Radiation after surgery was another predictor of OS of PGS (P < .001). Among all the radiation methods, combination of beam with implants or isotopes (P = .000, HR = 0.491, 95%CI = 0.412‐0.585) or radiation NOS (P = .027, HR = 0.362, 95%CI = 0.148‐0.889) were more beneficial to patients.

Conclusion

This study indicated that single PGS has a poor prognosis. Prognosis of single PGS would become poorer along with patients' age and tumor size (>40 mm). Surgery intervention and radiation therapy were beneficial factors.

Primary Gliosarcoma of the Cerebellum in a Young Pregnant Woman: Management Challenges and Immunohistochemical Features

Background

Gliosarcoma (GS) represents a rare, high-grade (WHO Grade IV), central nervous system neoplasm, characterized by a very poor prognosis. Similar to other high-grade gliomas, GS affects mainly adults in the 5^th-7^th decade of life and presents a higher incidence in males. The most reported locations of GS are the temporal lobe and the frontal lobe, while only eight cases of GS originating from the posterior cranial fossa are reported in the literature.

Case Description

We report the first case occurring during pregnancy in a 33-year-old patient. Diagnosis was obtained on the 15^th week of gestation when patient presented with signs and symptoms of life-threatening raised intracranial pressure. Surgical excision was followed by early recurrence and eventually disease progression because the patient refused adjuvant treatment to save her fetus.

Conclusions

GS should be considered in the differential diagnosis of posterior cranial fossa tumors with radiological features of meningioma or glioblastoma, even in young patients. To this regard, sarcomas, solitary fibrous tumors, and even metastases should be considered, especially in light of the tendency of GS to give rise to extracranial localizations. Whenever an aggressive management with radical excision and adjuvant treatment is not safely achievable, disease progression is likely to be unavoidable.

Prognosis and management of gliosarcoma patients: A review of literature

Gliosarcoma (GSM) is a variant of glioblastoma (GBM), the most common primary malignant brain tumor that occurs in adults. GSM is characterized by its biphasic components: the gliomatous and sarcomatous components and categorized into primary and secondary GSM. Intrinsic to the brain parenchyma, GSM is usually managed by gross total resection, and radiotherapy with/without chemotherapy. While the benefits of treatment remain unclear, cases have always been managed similar to GBM cases yielding different treatment outcomes between the two groups. The scarcity of research done on GSM suggests that further investigation is needed. Genetic studies on tumor samples and an in-depth examination of tumor subtypes and categories could result in identification of certain targetable alterations. The objective of this review is to summarize the available findings on characteristics, prognosis and management of GSM patients.

Clinical and molecular characteristics of gliosarcoma and modern prognostic significance relative to conventional glioblastoma

Gliosarcoma is a rare histopathologic variant of glioblastoma traditionally associated with a poor prognosis. While gliosarcoma may represent a distinct clinical entity given its unique histologic composition and molecular features, its relative prognostic significance remains uncertain. While treatment of gliosarcoma generally encompasses the same standardized approach used in glioblastoma, supporting evidence is limited given its rarity. Here, we characterized 32 cases of gliosarcoma and retrospectively evaluated survival relative to 451 glioblastoma patients diagnosed during the same era within the same institution. Overall, we identified 22 primary gliosarcomas, representing 4.7% of WHO Grade IV primary glioblastomas, and 10 secondary gliosarcomas. With median age of 62, patients were predominately Caucasian (87.5%) and male (65.6%). Tumors with available molecular profiling were primarily MGMT-unmethylated (87.5%), IDH-1-preserved (100%) and EGFR wild-type (100%). Interestingly, while no significant median survival difference between primary gliosarcoma and glioblastoma was observed across the entire cohort (11.0 vs. 14.8 months, p = 0.269), median survival was worse for gliosarcoma specifically among patients who received modern temozolomide-based (TMZ) chemoradiotherapy (11.0 vs. 17.3 months, p = 0.006). Matched-pair analysis also trended toward worse median survival among gliosarcomas (11.0 vs. 19.6 months, log-rank p = 0.177, Breslow p = 0.010). While adjuvant radiotherapy (HR 0.206, p = 0.035) and TMZ-based chemotherapy (HR 0.531, p = 0.000) appeared protective, gliosarcoma emerged as a significantly poor prognostic factor on multivariate analysis (HR 3.27, p = 0.012). Collectively, our results suggest that gliosarcoma may still portend worse prognosis even with modern trimodality therapy.

Primary gliosarcoma: epidemiology, clinical presentation, management, and survival

BACKGROUND

Gliosarcomas are malignant tumors of the central nervous system. As a variant of glioblastomas (GBM), they are treated in a similar fashion. However, there is growing evidence to suggest that they may be a separate entity.

METHODS

Due to the rarity of primary gliosarcomas (PGS), here we publish data from a single center spanning over 14 years, comprising possibly one of the biggest case series in the literature to our knowledge.

RESULTS

The mean age at presentation was 59 years with male preponderance (1.75:1). The most common presenting symptoms were balance and mobility issues (61%), followed by headaches (50%) and visual problems (39%). Tumours were most likely to involve the frontal and parietal lobes (27% and 21% respectively). Patients under 50 had a significant survival advantage (50% versus 32%). All patients had surgery, 79% had adjuvant radiotherapy, with a further 21% also receiving chemotherapy. Median survival from surgery of patients diagnosed with PGS was 6.6 months. Median and one-year survival were significantly better for patients who received radiotherapy (14 months; 46% one year survival) and improved further with combined radio- and chemotherapy (30 months; 77%, one year survival).

CONCLUSIONS

For patients of good functional status, adjuvant chemo-radiotherapy is warranted and should be offered as it confers a much-improved overall survival.

Detailed magnetic resonance imaging features of a case series of primary gliosarcoma

Objective We aimed to characterise the magnetic resonance imaging (MRI) features of a case series of primary gliosarcoma, with the inclusion of diffusion-weighted imaging and perfusion imaging with dynamic susceptibility contrast MRI. Materials and methods We conducted a retrospective study of cases of primary gliosarcoma from the Pathology Department database from January 2006 to December 2014. Clinical and demographic data were obtained. Two neuroradiologists, blinded to diagnosis, assessed tumour location, signal intensity in T1 and T2-weighted images, pattern of enhancement, diffusion-weighted imaging and dynamic susceptibility contrast MRI studies on preoperative MRI. Results Seventeen patients with primary gliosarcomas had preoperative MRI study: seven men and 10 women, with a mean age of 59 years (range 27-74). All lesions were well demarcated, supratentorial and solitary (frontal n = 5, temporal n = 4, parietal n = 3); 13 tumours abutted the dural surface (8/13 with dural enhancement); T1 and T2-weighted imaging patterns were heterogeneous and the majority of lesions (12/17) showed a rim-like enhancement pattern with focal nodularities/irregular thickness. Restricted diffusion (mean apparent diffusion coefficient values 0.64 × 10^-3 mm²/s) in the more solid/thick components was present in eight out of 11 patients with diffusion-weighted imaging study. Dynamic susceptibility contrast MRI study ( n = 8) consistently showed hyperperfusion in non-necrotic/cystic components on relative cerebral volume maps. Conclusions The main distinguishing features of primary gliosarcoma are supratentorial and peripheral location, well-defined boundaries and a rim-like pattern of enhancement with an irregular thick wall. Diffusion-weighted imaging and relative cerebral volume map analysis paralleled primary gliosarcoma with high-grade gliomas, thus proving helpful in differential diagnosis.

Analysis of Outcomes of Multidisciplinary Management of Gliosarcoma: A Single-Center Study, 2000-2013

BACKGROUND

Gliosarcoma is a rare tumor of the central nervous system with a reported incidence of ∼2%-8% of all gliomas. We reviewed the outcomes of patients treated at our institution over a 14-year period from 2000 to 2013 to characterize overall survival (OS) and progression-free survival as well as to elucidate the additive effect of chemoradiotherapy.

METHODS

From January 1, 2000 to December 31, 2013, we retrospectively reviewed the clinical notes of all patients treated at our institution with a histopathologic diagnosis of gliosarcoma. This review yielded 21 patients whose clinicoradiologic data were analyzed with respect to age, sex, ethnicity, preoperative/postoperative Glasgow Coma Scale and Karnofsky Performance Scale, location, extent of resection, methylguanine DNA methyl transferase methylation status, and administration of adjuvant therapy.

RESULTS

The median age was 58 years (range, 40-80 years) with a male preponderance (1.6:1). Tumor location was mainly temporal (n = 6) but also parietal (n = 5), frontal (n = 4), multilobar (n = 4), and cerebellar (n = 1). Surgical resection was deemed to be total in 15 patients and subtotal in 6 patients. Methylguanine DNA methyl transferase methylation status was available for only 5 patients, with a methylation rate of 60% (3/5) and no impact on survival. Nine patients received both radiotherapy and chemotherapy (OS, 7.9 months), 7 received radiotherapy only (OS, 5.7 months), and 5 patients received no adjuvant therapy (OS, 1.4 months). The overall median survival was 5.7 months (range, 1-21.5 months) and median progression-free survival was 5 months (range, 1.4-12.4 months).

CONCLUSIONS

Despite an overall poor prognosis, a multimodality approach aiming for complete resection followed by radiotherapy and chemotherapy appears to be associated with better outcomes.

[Primary cerebral gliosarcoma: about two cases and review of the literature]

Gliosarcoma is a very rare brain tumor accounting for 1.8 -8% of all glial tumors. It has been classified by the World Health Organization as a variant of glioblastoma. It is a tumor with double glial and sarcomatous component. Patient's clinical picture is polymorphic, imaging data are evocative, diagnosis is based on histology. Treatment is always surgical. Prognosis is closely linked to the quality of resection. We here report two clinical cases with the aim of assessing the diagnostic, therapeutic and prognostic features of this rare entity.

Gliosarcoma in Young Adults: A Rare Variant of Glioblastoma

Gliosarcoma is a rare central nervous system (CNS) malignancy. It is characterized by classical biphasic histological pattern with both glial and sarcomatous components, often seen in fifth and sixth decade of life. They are generally located in the supratentorial region. Due to its rarity, exact treatment recommendations are not available in literature. Since it is considered as a variant of glioblastoma multiforme (GBM), it is treated with surgery followed by adjuvant radiotherapy and temozolomide-based chemotherapy. We present a series of four cases of this rare malignancy that were treated at our institute.

High prevalence of TP53 mutations is associated with poor survival and an EMT signature in gliosarcoma patients

Gliosarcoma (GS) is a rare variant (2%) of glioblastoma (GBM) that poses clinical genomic challenges because of its poor prognosis and limited genomic information. To gain a comprehensive view of the genomic alterations in GS and to understand the molecular etiology of GS, we applied whole-exome sequencing analyses for 28 GS cases (6 blood-matched fresh-frozen tissues for the discovery set, 22 formalin-fixed paraffin-embedded tissues for the validation set) and copy-number variation microarrays for 5 blood-matched fresh-frozen tissues. TP53 mutations were more prevalent in the GS cases (20/28, 70%) compared to the GBM cases (29/90, 32%), and the GS patients with TP53 mutations showed a significantly shorter survival (multivariate Cox analysis, hazard ratio=23.9, 95% confidence interval, 2.87-199.63, P=0.003). A pathway analysis showed recurrent alterations in MAPK signaling (EGFR, RASGRF2 and TP53), phosphatidylinositol/calcium signaling (CACNA1s, PLCs and ITPRs) and focal adhesion/tight junction (PTEN and PAK3) pathways. Genomic profiling of the matched recurrent GS cases detected the occurrence of TP53 mutations in two recurrent GS cases, which suggests that TP53 mutations play a role in treatment resistance. Functionally, we found that TP53 mutations are associated with the epithelial-mesenchymal transition (EMT) process of sarcomatous components of GS. We provide the first comprehensive genome-wide genetic alternation profiling of GS, which suggests novel prognostic subgroups in GS patients based on their TP53 mutation status and provides new insight in the pathogenesis and targeted treatment of GS.

Case of glioblastoma patient treated with tumor treating fields therapy at recurrence degenerating to sarcoma

Optune^® treatment is a US FDA-approved treatment for glioblastoma (GBM) that employs alternating electric fields. Tumor treating field (TTF) therapy can exert its effects on GBM via cell cycle mitosis disruption and cytokinesis. We describe a patient with recurrent GBM who had disease progression following standard surgical treatment and concomitant chemoradiotherapy, and was found to have sarcomatous transformation after initiation of TTF therapy with bevacizumab. Upon tumor progression, repeat surgical resection revealed transformation into a GFAP-negative, reticulin-positive sarcoma with rhabdomyoid features. The possibility of a causal connection between TTF therapy and sarcomatous transformation needs to be further evaluated. No such case of apparent sarcoma formation in the CNS following chemoradiotherapy and/or TTF treatment for GBM has been reported.

An IDH1-mutated primary gliosarcoma: case report

The authors present the case of a primary gliosarcoma with an isocitrate dehydrogenase-1 (IDH1) mutation. A 75-year-old man presented with a 3-day history of multiple focal seizures and was found on MRI to have a 2.2-cm left parietal enhancing mass lesion. Brain MRI for tremor performed 8 years prior to this presentation was normal. En bloc resection revealed a high-grade glioma with sarcomatous components that was immunoreactive for the R132H variant of IDH1 by antibody. Gliosarcoma is a rare variant of glioblastoma that arises most frequently as a primary tumor, and has equal or worse survival and an increased propensity for extracranial metastases compared with other Grade 4 gliomas. In contrast, isocitrate dehydrogenase-1 and -2 mutations are associated with low-grade gliomas with increased survival and less commonly with glioblastoma. To the authors' knowledge, there has been only 1 other published report of a primary gliosarcoma carrying an isocitrate dehydrogenase mutation. This rare genetic-histological combination highlights potential differences between glioblastoma and gliosarcoma and may warrant additional study.

Brachium Pontis Gliosarcoma With Well-Differentiated Cartilaginous Tissue: A Case Report

Gliosarcoma (GS) belongs to World Health Organization grade IV neoplasm and displaying glial and mesenchymal differentiation. Only rare cases of GS have been reported in the brachium pontis and 4th ventricle region. Here, we report a rare case of GS located on brachium pontis region and extending into the 4th ventricle with well-differentiated cartilaginous metaplasia. A 28-year-old male patient experienced intermittent headache, vomiting, and gait disorders for 3 months. Magnetic resonance imaging (MRI) showed a heterogeneous ring-enhancement lesion with weak central enhancement in left brachium pontis and 4th ventricle region. Histology revealed the GS was constituted with glial and sarcomatous elements. After immunohistochemical analysis, a diagnosis of GS with cartilaginous differentiation was then made.Symptoms of GS, including headache, aphasia, hemiparesis, cognitive decline, and seizures, mainly determined by the location. The clinical manifestation and radiologic characteristic is not significantly different from that of glioblastoma. The grade of resection is the significant factor related to prognosis of GS, and the clinical effect of adjuvant radiotherapy and chemotherapy need further study. Reporting additional cases would be of great help in better understanding of this location and pathologic type of GS.

Primary and secondary gliosarcomas: clinical, molecular and survival characteristics

Gliosarcoma is classified by the World Health Organization as a variant of glioblastoma. These tumors exhibit biphasic histologic and immunophenotypic features, reflecting both glial and mesenchymal differentiation. Gliosarcomas can be further classified into primary (de novo) tumors, and secondary gliosarcomas, which are diagnosed at recurrence after a diagnosis of glioblastoma. Using a retrospective review, patients seen at MD Anderson Cancer Center between 2004 and 2014 with a pathology-confirmed diagnosis of gliosarcoma were identified. 34 patients with a diagnosis of gliosarcoma seen at the time of initial diagnosis or at recurrence were identified (24 primary gliosarcomas (PGS), 10 secondary gliosarcomas (SGS)). Molecular analysis performed on fourteen patients revealed a high incidence of TP53 mutations and, rarely, EGFR and IDH mutations. Median overall survival (OS) for all patients was 17.5 months from the diagnosis of gliosarcoma, with a progression free survival (PFS) of 6.4 months. Comparing PGS with SGS, the median OS was 24.7 and 8.95 months, respectively (from the time of sarcomatous transformation in the case of SGS). The median OS in SGS patients from the initial diagnosis of GB was 25 months, with a PFS of 10.7 months. Molecular analysis revealed a higher than expected rate of TP53 mutations in GS patients and, typical of primary glioblastoma, IDH mutations were uncommon. Though our data shows improved outcomes for both PGS and SGS when compared to the literature, this is most likely a reflection of selection bias of patients treated on clinical trials at a quaternary center.

Cerebral gliosarcoma: Analysis of 16 patients and review of literature

BACKGROUND

Gliosarcoma (GS), a subtype of glioblastoma (GBM), is a rare primary neoplasm of the central nervous system. Certain features like temporal lobe affinity, tendency for extraneural metastasis and poorer outcome compared to GBM indicate that GS may indeed be a separate clinicopathologic entity. This led us to revisit this entity in our settings.

MATERIALS AND METHODS

Between 2009 and 2014, 16 cases of histologically proven GSs (14 primary, two secondary) were treated. Patient data were retrieved retrospectively. Statistical analysis was performed with? Statistical Package for Social Sciences, version 17.0. (Chicago, Illinois, USA). Survival was analyzed by Kaplan-Meier method.

RESULTS

GS predominantly affected males in their fifth decade of life. Raised intracranial pressure was the most common mode of clinical presentation. Temporal lobe was the most commonly affected part of the brain and majority of primary and all of secondary GBM were located peripherally. In 7 (43.8%) patients, tumor was radiologically well-demarcated and enhanced strongly and homogenously on contrast as compared to 9 (56.2%) patients where the tumor was ill-defined and showed heterogenous patchy or ring enhancement. Extent of excision was total in seven patients (43.8%), near total in 4 (25%) and subtotal in five patients (31.2%). Median survival was 6 months. Patients with well-demarcated, enhancing mass on imaging intraoperatively had firm tumors with a good plane of cleavage and had a better survival (8 months) compared to those in whom the tumor radiologically and intraoperatively mimicked GBM (2 months).

CONCLUSION

GS is associated with poor survival (median survival 6 months). Radiological and intraoperative findings help categorize these tumors into GBM like GS and meningioma like GS. While the former histologically mimics GBM and has very poor survival (2 months), GS with meningioma like feature tends to have better survival (8 months).

Impact of changing trends of treatment on outcome of cerebral gliosarcoma: A tertiary care centre experience

AIM

To assess clinicopathological features and outcomes in patients of primary gliosarcoma with changing trends of treatment.

MATERIALS AND METHODS

Medical records were reviewed and data collected on primary gliosarcoma over a 5-year period (2009-2013) from the departmental case files.

RESULTS

A total 27 patients were included in this study. The median age of presentation was 54 years. There was a slight male preponderance, with male to female ratio of 1.25:1. The most common location of the tumor was temporal lobe (44.4%). Gross total resection was possible in 19 cases, near total excision was done in five cases, and only partial excision with decompression in three cases. Of the 27 patients, 80.8% patients received post-operative radical external beam radiotherapy of 60 Gy/30#/6 weeks. Concurrent and adjuvant temozolomide was used in 42.3% cases, depending on affordability and tolerance. Median overall survival was 9 months. On subgroup analysis, median overall survival in the radiotherapy plus temozolomide group was 10 months as compared to 9 months in the radiotherapy alone group; however, this was not statistically significant.(P = 0.244).

CONCLUSION

Treating Gliosarcoma is a major therapeutic challenge for a clinician because of its poor prognosis, aggressive clinical behavior, rarity, and limited clinical experience. With surgery and concurrent chemoradiation, we were able to achieve a median overall survival of 9 months. Addition of temozolomide has shown a better trend in survival though it is not statistically significant.

[Spinal cord metastasis from gliosarcoma. Case report and review of the literature]

INTRODUCTION

Gliosarcoma is a rare neoplasm of the central nervous system, similar to glioblastoma multiforme. In contrast to glioblastoma, it is characterised by its propensity for extracranial metastasis (11% of the cases) due to its sarcomatous component. Intramedullary metastasis from primary gliosarcoma is extremely rare.

CASE REPORT

A patient who had surgery for primary cerebral gliosarcoma developed paraparesis during the course of the disease. A magnetic resonance image showed an intramedullary spinal cord metastasis requiring surgical treatment. This article reviews the literature on intramedullary spinal cord metastasis from gliosarcoma, and highlights the characteristics, treatment and overall survival.

CONCLUSIONS

Only 4 cases of intramedullary gliosarcoma metastasis are described in the literature. This extremely rare entity should be suspected with the onset of spinal cord symptoms during the course of primary cerebral gliosarcoma.

Secondary gliosarcoma with extra-cranial metastases: a report and review of the literature

OBJECTIVE

To describe a unique case of secondary gliosarcoma (SGS) with widespread extra-cranial metastases that developed more than 5 years after the initial diagnosis of glioblastoma multiforme (GBM). This interval is the longest among the cases reported to date.

METHODS

A PUBMED search using the key words "secondary gliosarcoma" and "extra-cranial metastases" was performed followed by a review of cited literature.

RESULTS

Including our report, we found 44 cases of SGS, of which only 5 developed extra-cranial metastases.

CONCLUSION

SGS with extra-cranial metastases is extremely rare. Of previously reported cases, the longest survival was 2 months after the diagnosis of SGS. The present case had a survival of 6.5 months. Our case highlights the importance of screening for extra-cranial metastases in SGS. The optimal treatment of SGS is not known and strategies based on GBM and sarcoma treatments have been employed with limited success. A combination of treatment modalities may extend survival as in the present report; however the prognosis remains poor.

A case study of a patient with gliosarcoma with an extended survival and spinal cord metastases

Gliosarcoma is a rare brain tumor consisting of both glial and mesenchymal components. Metastatic gliosarcoma is rare; however, here we report a 31-year-old Chinese woman with cranial gliosarcoma metastatic to the liver, lymph nodes and the spinal cord. Initially, the patient presented with dizziness, headache and vomiting and after surgery and histological examination, was diagnosed with cranial gliosarcoma. The patient was treated with surgical resection followed by chemotherapy and radiotherapy. Three years after completing treatment, the patient again presented with similar symptoms with the addition of a seizure. Test revealed recurrence of the gliosarcoma, and the same treatment was prescribed. Three years after treatment completion, the patient again presented with dizziness and headache. Masses at the right temple and in the right side of the neck were found. Tumors were surgically removed from the brain, skull, scalp and neck, the latter three diagnosed as metastatic gliosarcomas. The patient received both chemotherapy and radiotherapy following resection. One month after treatment, bone scans revealed possible metastasis in the right skull, lumbar and left ileum, soft neck tissue, lungs, collarbone, humeri, vertebrae, liver and abdominal lymph nodes. No further therapy was recommended due to the poor condition of the patient. The patient died 5 months later.

Radiological findings in gliosarcoma. A single institution experience

Gliosarcomas are rare tumors with a poor prognosis composed of intermingled malignant glial and sarcoma elements with an estimated incidence of 1.8-8.0% of all malignant astrocytic neoplasms. We aimed to review the imaging findings in eight patients with gliosarcoma who were treated in our center between 2002 and 2010. The diagnosis was confirmed by morphological and immunohistochemical stains. This study, to the best of our knowledge, is the largest describing the imaging manifestations of this tumor. Although our study revealed no unique radiological features for gliosarcoma, it is important to note that they all demonstrated either dural or ependymal involvement or both. Calcification, hemorrhage or cystic components are described with a tendency for a ring enhancement pattern. Interestingly pre-existing benign looking lesions and associated remotely located small meningiomas are also described.

Posterior fossa involvement in a recurrent gliosarcoma

Gliosarcoma (GSM) is a WHO grade 4 tumor and a variant of glioblastoma multiforme with predilection for the temporal lobe. We record, perhaps the first case in literature, of a temporal lobe GSM with recurrence involving the posterior fossa. A 50-year-old man presented to us with headache, vomiting, and lethargy of relatively recent onset. Magnetic resonance imaging revealed a well-circumscribed lesion in the left temporal lobe for which left temporal craniotomy with radical excision of the tumor was performed. Histopathology was suggestive of GSM. He presented to us within a month of the first surgery with a large recurrence involving the temporal lobe. He underwent a second surgery with radical excision of the tumor. Histopathology was confirmatory of GSM. He was administered concomitant chemotherapy and radiotherapy. Within a fortnight of starting adjuvant therapy, the bone flap started bulging and a repeat computed tomography scan revealed a large recurrence extending into the posterior fossa. The patient's relatives refused consent for third surgery and he finally succumbed on postoperative day 21. GSMs are aggressive tumors that have a temporal lobe predilection, but they may present anywhere in the brain. Detailed studies on larger cohort of cases are needed to understand the true nature of these biphasic tumors.

Clinicopathologic and genomic features of gliosarcomas

Gliosarcoma is a variant of glioblastoma (GBM) with both glial and mesenchymal differentiation. The genetic profile of gliosarcoma is similar to that of primary GBM, except for rare EGFR amplification. However, little is known about O6-methylguanine-DNA methyltransferase (MGMT) methylation and isocitrate dehydrogenase (IDH) 1/2 mutations in gliosarcomas. The objective of this study was to investigate the status of MGMT methylation and IDH1/2 mutations, and to determine the effect of current treatment options for 26 patients with gliosarcoma. Among 26 cases, 21 were primary gliosarcomas, four secondary gliosarcomas, and one radiation-induced gliosarcoma. MGMT methylation was detected in three cases (11.5%), of which one was found in primary gliosarcoma and two in secondary gliosarcoma. IDH1 mutation was found in two cases (7.7%), of which one was in secondary gliosarcoma and the other in primary gliosarcoma with MGMT methylation. A case of primary gliosarcoma with both IDH1 mutation and MGMT methylation had a focal oligodendroglial component. No IDH2 mutation was found. Patients who underwent gross total resection (GTR) during first surgery had better survival (mean overall survival 18.1 vs. 9.04 months; P = 0.0543). In multivariate analysis, GTR and/or gamma knife surgery at recurrence was the independent favorable prognostic factor (P = 0.0003). In conclusion, MGMT methylation and IDH1 mutation are rare events in gliosarcomas, and only aggressive and repetitive local control seems to be effective in treatment of gliosarcoma.

Gliosarcoma arising from a fibrillary astrocytoma

We report a 67-year-old woman who was diagnosed with a gliosarcoma at a second operation after diagnosis of a fibrillary astrocytoma 5 months previously. Initially, she underwent a CT-guided stereotactic biopsy. Histological examination showed fibrillary astrocytoma (World Health Organization [WHO] grade II). Loss of heterozygosity (LOH) on 1p, 10q, and 19q was not detected. She received chemotherapy, but no radiotherapy. Five months after the biopsy, MRI revealed rapid tumor growth. Tissue obtained from partial removal of the tumor revealed gliosarcoma (WHO grade IV), and LOH on 10q and 19q was detected. The history, histopathology, and genetic alterations of this patient are discussed.

Primary gliosarcoma--clinical experience from a regional cancer centre in north India

AIMS

We intended to assess the clinicopathological features and treatment outcome in patients of primary gliosarcoma, a rare malignant brain tumour.

MATERIALS AND METHODS

Medical records were reviewed and data collected on primary gliosarcoma over an 8-year period (2002-2009) from the departmental archives. Overall survival (OS) was analysed by Kaplan-Meier method.

RESULTS

Seventeen patients met the study criterion (male:female = 9:8). Median age and performance status at presentation were 50 years and Karnofsky performance scale (KPS) 70, respectively. Symptoms of raised intracranial tension (in 100%) and motor impairment (in 64.7%) were commonly observed. Tumour location was frontal in four patients, temporal in three, parietal in three, thalamic in one, multilobed in five and multicentric in one. All patients underwent maximal safe surgery (total excision-10, near-total excision-2, subtotal excision and decompression-5). On histopathology, all tumours showed biphasic pattern, glial component positive for glial fibrillary acidic protein (GFAP) and mesenchymal component positive for vimentin and reticulin. Atypia, mitoses, necrosis and endothelial proliferation were identified in the glial component. Post-operative radiotherapy (median dose--60 Gy/30#/6 weeks) was used in 15 patients (88.2%). Concurrent and adjuvant chemotherapy with temozolomide (TMZ) were used in two patients depending upon affordability. After the completion of treatment, 35.3% patients were asymptomatic, 23.5% had symptomatic improvement, while 41.2% deteriorated. Salvage therapy for local recurrence was used in three patients (temporal lobectomy-1; total excision-1; TMZ+bevacizumab-1). At last follow-up (FU), eight patients were alive, seven patients dead and two patients lost to FU with symptom. Median overall survival in the evaluable patients (N = 15) was noted to be 8.27 months (6 month survival 60.76%).

CONCLUSIONS

Primary gliosarcoma, a variant of glioblastoma poses clinical challenge because of rarity, poor prognosis and limited experience. In our centre, principle of therapy is akin to that of glioblastoma--surgery followed by radiation along with concurrent and adjuvant TMZ. However, chemotherapy is often cost-prohibitive in our setting as mirrored by limited use (17.6%). Median survival of only 8.27 months in our series is in concert with the existing survival result of primary gliosarcoma in world literature (6.25-11.5 months).

Gliosarcoma: a study of four cases

Gliosarcomas (GS) are highly malignant and rare tumors of the central nervous system with a poor prognosis. We report here on four patients with GS, the median survival for whom was 9.25 months. Prognosis of GS remains poor, and a multidisciplinary approach (surgery, radiation therapy, and chemotherapy) seems to be associated with slightly more prolonged survival times.

Secondary gliosarcoma after diagnosis of glioblastoma: clinical experience with 30 consecutive patients

OBJECT

Gliosarcoma can arise secondarily, after conventional adjuvant treatment of high-grade glioma. The current literature on the occurrence of secondary gliosarcoma (SGS) after glioblastoma multiforme (GBM) is limited, with only 12 reported cases. The authors present a large series of histologically confirmed SGSs, with follow-up to describe the clinical and radiological presentation, pathological diagnosis, and treatment outcomes.

METHODS

Gliosarcoma cases were identified using the University of California, San Francisco's Departments of Neurological Surgery and Neuropathology databases. Through a retrospective chart review, cases of gliosarcoma were considered SGS if the following inclusion criteria were met: 1) the patient had a previously diagnosed intracranial malignant glioma that did not have gliosarcoma components; and 2) the histopathological tissue diagnosis of the recurrence confirmed gliosarcoma according to the most current WHO criteria. Extensive review of clinical, surgical, and pathology notes was performed to gather clinical and pathological data on these cases.

RESULTS

Thirty consecutive patients in whom SGS had been diagnosed between 1996 and 2008 were included in the analysis. All patients had previously received a diagnosis of malignant glioma. For the initial malignant glioma, all patients underwent resection, and 25 patients received both external-beam radiation and chemotherapy. Three patients received radiotherapy alone, 1 patient was treated with chemotherapy alone, and 1 patient's tumor rapidly recurred as gliosarcoma, requiring surgical intervention prior to initiation of adjuvant therapy. The median time from diagnosis of the initial tumor to diagnosis of gliosarcoma was 8.5 months (range 0.5-25 months). All but 1 patient (who only had a biopsy) underwent a second operation for gliosarcoma; 8 patients went on to receive radiotherapy (4 had brachytherapy, 3 had external-beam radiation, and 1 had Gamma Knife surgery); and 14 patients received additional chemotherapy. The median length of survival from the time of gliosarcoma diagnosis was 4.4 months (range 0.7-46 months). The median survival from the time of the original GBM diagnosis was 12.6 months (range 5.7-47.4 months). Patients who had received concurrent and adjuvant temozolomide for GBM had worse outcomes than those who had not (4.3 and 10.5 months, respectively; p = 0.045). There was no difference in time to diagnosis of gliosarcoma in these 2 groups (8 and 8.5 months; p = 0.387). Two patients who had not received radiation therapy for GBM had an anecdotally very prolonged survival (20.9 and 46.4 months).

CONCLUSIONS

The data underscore the difficulty associated with management of this disease. The strikingly poor survival of patients with SGS who had previously received combined radiation and temozolomide chemotherapy for GBM may reflect a unique molecular profile of GBM that eventually recurs as SGS. Further work will be required, controlling for multiple prognostic factors with larger numbers of patients.

Gliosarcoma stem cells undergo glial and mesenchymal differentiation in vivo

Cancer stem cells (CSCs) are characterized by their self-renewing potential and by their ability to differentiate and phenocopy the original tumor in orthotopic xenografts. Long-term propagation of glioblastoma (GBM) cells in serum-containing medium results in loss of the CSCs and outgrowth of cells genetically and biologically divergent from the parental tumors. In contrast, the use of a neurosphere assay, a serum-free culture for selection, and propagation of central nervous system-derived stem cells allows the selection of a subpopulation containing CSCs. Gliosarcoma (GS), a morphological variant comprising approximately 2% of GBMs, present a biphasic growth pattern, composed of glial and metaplastic mesenchymal components. To assess whether the neurosphere assay would allow the amplification of a subpopulation of cells with "gliosarcoma stem cell" properties, capable of propagating both components of this malignancy, we have generated neurospheres and serum cultures from primary GS and GBM surgical specimens. Neurosphere cultures from GBM and GS samples expressed neural stem cell markers Sox2, Musashi1, and Nestin. In contrast to the GBM neurosphere lines, the GS neurospheres were negative for the stem cell marker CD133. All neurosphere lines generated high-grade invasive orthotopic tumor xenografts, with histological features strikingly similar to the parental tumors, demonstrating that these cultures indeed are enriched in CSCs. Remarkably, low-passage GS serum cultures retained the expression of stem cell markers, the ability to form neurospheres, and tumorigenicity. The GS experimental tumors phenocopied the parental tumor, exhibiting biphasic glial and mesenchymal components, constituting a clinically relevant model to investigate mesenchymal differentiation in GBMs.

Transformation of intracranial anaplastic astrocytoma associated with neurofibromatosis type I into gliosarcoma: case report

Gliosarcoma is an uncommon malignant brain tumor composed of distinct sarcomatous and malignant glial cell elements. These tumors are defined as a variant of glioblastoma, and it can be developed by progression of the malignant glial cell tumors or primary tumors. We report a rare case with gliosarcomatous recurrence of anaplastic astrocytoma with neurofibromatosis type 1 (NF-1) followed by chemoradiation therapy. A 26-year-old male patient was presented with headache. Five years before admission, he had been diagnosed with NF-1. Magnetic resonance imaging (MRI) showed a well-demarcated, enhanced lesion in the right frontal lobe and multiple enhanced lesions in the scalp, lower cervical, thoracic, and upper lumbar regions. He underwent an osteoplastic craniotomy with total tumor resection. Histopathology of the tumor showed findings corresponding with anaplastic astrocytoma. He was followed by radiotherapy and chemotherapy postoperatively. A month later, his spinal lesion was also resected and confirmed pathologically as plexiform neurofibroma. The subsequent follow-up period of 27 months was uneventful until he developed a generalized tonic-clonic seizure. MRI showed tumor recurrence in the original site of the tumor. Re-exploration was carried out. Pathological examination displayed a biphasic pattern of the glial and sarcomatous components suggesting gliosarcoma.

Clinical characteristics and outcomes for a modern series of primary gliosarcoma patients

BACKGROUND

Primary gliosarcoma (PGS) is a rare central nervous system tumor with limited experience reported in the literature. In the current study, the authors present a modern series of confirmed PGS cases treated in the era of magnetic resonance imaging (MRI), after the accepted glioblastoma management of resection, radiation, and temozolomide.

METHODS

Using a retrospective review, patients with confirmed PGS were identified (1996-2008). Cases were determined to be PGS by central pathology review using the 2007 World Health Organization criteria. Extensive chart review was performed to gather clinical and pathologic data on these cases.

RESULTS

All but 1 patient had undergone a preoperative MRI, with 1 patient receiving a computed tomography scan due to a cardiac pacemaker. A total of 10 patients received radiotherapy with concurrent and adjuvant temozolomide chemotherapy, and 8 patients received radiotherapy alone or in combination with other chemotherapeutic agents. In 2 patients, the history of adjuvant treatment could not be confirmed. The overall median survival was 13.9 months (range, 2.2-22.9 months). Patients with gliosarcomas resembling meningioma were found to have a significantly prolonged median survival compared with patients harboring gliosarcoma resembling glioblastoma multiforme (16 months vs 9.6 months; P = .011). However, no difference in survival was noted between patients who received concurrent radiotherapy and temozolomide compared with those who did not (10.4 months vs 13.9 months; P = .946).

CONCLUSIONS

The results of the current study support previous hypotheses that there are 2 distinct types of PGS. The type mimicking the appearance of a meningioma appears to carry a significantly more favorable prognosis, most likely due to an increased chance at achieving macroscopic total resection.