Gliosarcoma with neuroaxis metastases

An autopsy case of primary gliosarcoma with multiple extracranial metastases: pathology after administration of bevacizumab and genetic profile

Gliosarcoma (GS), a morphological variant of glioblastoma, pathologically shows a biphasic pattern with gliomatous and sarcomatous components. It has been reported that GS has much higher metastatic capacity than glioblastoma. A few reports on the pathology of the extracranial metastasis of GS have shown that metastatic lesions had a sarcomatous component alone or a mixture of gliomatous and sarcomatous ones. Therefore, it is considered that GS tends to disseminate hematogenously due to its mesenchymal sarcomatous component. Herein, we report an autopsy case of GS with multiple extracranial metastases treated by craniotomy, radiotherapy, and bevacizumab. In this case, metastatic lesions at autopsy contained a gliomatous component alone, but no sarcomatous component. In addition, the sarcomatous component disappeared from the intracranial lesion at autopsy after the administration of bevacizumab. In this report, we discuss the clinical course and pathological findings at the initial state, recurrence, and autopsy, including the results of whole-genome analysis.

Metastatic secondary gliosarcoma: patient series

BACKGROUND

Gliosarcoma is a rare and highly malignant cancer of the central nervous system with the ability to metastasize. Secondary gliosarcoma, or the evolution of a spindle cell-predominant tumor after the diagnosis of a World Health Organization grade IV glioblastoma, has also been shown to metastasize. There is little information on metastatic secondary gliosarcoma.

OBSERVATIONS

The authors present a series of 7 patients with previously diagnosed glioblastoma presenting with recurrent tumor and associated metastases with repeat tissue diagnosis consistent with gliosarcoma. The authors describe the clinical, imaging, and pathological characteristics in addition to carrying out a systematic review on metastases in secondary gliosarcoma.

LESSONS

The present institutional series and the systematic review of the literature show that metastatic secondary gliosarcoma is a highly aggressive disease with a poor prognosis.

A Rare Tumor in a Rare Location: Radiology and Pathology Findings With a Literature Review on Intraventricular Gliosarcoma

Gliosarcoma (GS) is an extraordinarily rare variant of glioblastoma, which is differentiated by its distinct biphasic histopathological morphology consisting of both glial and mesenchymal elements. Although GS has a predilection for the cortical hemispheres, rare occurrences of intraventricular gliosarcoma (IVGS) have been documented in the literature. In this report, we present a 68-year-old female patient with a primary IVGS arising from the frontal horn of the left ventricle with corresponding left ventricular entrapment. The clinical course as well as associated tumor features as observed on computed tomography (CT), magnetic resonance imaging (MRI), and immunohistochemical studies are presented along with a relevant review of the current literature.

Multidisciplinary approaches to gliosarcoma: A case report and review of the literature

A 58-year-old right-handed man presented to our tertiary care center with gliosarcoma (GS) infiltration through the dura, skull, and soft tissue. Patient had a previous history of right temporal GS, with four intracranial surgeries prior to presentation. A multidisciplinary approach was used to treat the lesion and perform reconstruction.

Machine Learning-Based Analysis of Magnetic Resonance Radiomics for the Classification of Gliosarcoma and Glioblastoma

Objective

To identify optimal machine-learning methods for the radiomics-based differentiation of gliosarcoma (GSM) from glioblastoma (GBM).

Materials and Methods

This retrospective study analyzed cerebral magnetic resonance imaging (MRI) data of 83 patients with pathologically diagnosed GSM (58 men, 25 women; mean age, 50.5 ± 12.9 years; range, 16-77 years) and 100 patients with GBM (58 men, 42 women; mean age, 53.4 ± 14.1 years; range, 12-77 years) and divided them into a training and validation set randomly. Radiomics features were extracted from the tumor mass and peritumoral edema. Three feature selection and classification methods were evaluated in terms of their performance in distinguishing GSM and GBM: the least absolute shrinkage and selection operator (LASSO), Relief, and Random Forest (RF); and adaboost classifier (Ada), support vector machine (SVM), and RF; respectively. The area under the receiver operating characteristic curve (AUC) and accuracy (ACC) of each method were analyzed.

Results

Based on tumor mass features, the selection method LASSO + classifier SVM was found to feature the highest AUC (0.85) and ACC (0.77) in the validation set, followed by Relief + RF (AUC = 0.84, ACC = 0.72) and LASSO + RF (AUC = 0.82, ACC = 0.75). Based on peritumoral edema features, Relief + SVM was found to have the highest AUC (0.78) and ACC (0.73) in the validation set. Regardless of the method, tumor mass features significantly outperformed peritumoral edema features in the differentiation of GSM from GBM (P < 0.05). Furthermore, the sensitivity, specificity, and accuracy of the best radiomics model were superior to those obtained by the neuroradiologists.

Conclusion

Our radiomics study identified the selection method LASSO combined with the classifier SVM as the optimal method for differentiating GSM from GBM based on tumor mass features.

Hypermutated phenotype in gliosarcoma of the spinal cord

Gliosarcoma is a variant of glioblastoma with equally poor prognosis and characterized by mixed glial and mesenchymal pathology. Metastasis is not uncommon but the involvement of the spinal cord is rare, and comprehensive genetic characterization of spinal gliosarcoma is lacking. We describe a patient initially diagnosed with a low-grade brain glioma via biopsy, followed by adjuvant radiation and temozolomide treatment. Nearly 2 years after diagnosis, she developed neurological deficits from an intradural, extramedullary tumor anterior to the spinal cord at T4, which was resected and diagnosed as gliosarcoma. Whole-exome sequencing (WES) of this tumor revealed a hypermutated phenotype, characterized by somatic mutations in key DNA mismatch repair (MMR) pathway genes, an abundance of C>T transitions within the identified somatic single nucleotide variations, and microsatellite stability, together consistent with temozolomide-mediated hypermutagenesis. This is the first report of a hypermutator phenotype in gliosarcoma, which may represent a novel genomic mechanism of progression from lower grade glioma.

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.