A rare variant of glioblastoma IDH wildtype, comprising 2–8% of glioblastomas. Histology features a biphasic tissue pattern consisting of areas of glial differentiation alternating with areas of mesenchymal differentiation.
May arise de novo, or can develop following glioblastoma treatment. May also appear in conjunction with ependymoma (ependymosarcoma) and oligodendroglioma (oligosarcoma). Gliosarcomas that are predominantly sarcomatous may enhance homogeneously and can mimic a meningioma.
It is estimated that approximately 2.1% of all glioblastomas are gliosarcomas.
Gliosarcomas have an epidemiology similar to that of glioblastomas, with the average age of onset being 54 years, and males being affected twice as often as females. They are most commonly present in the temporal lobe.
Wu et al have selected a group of DNA aptamers with high affinity and selectivity against gliosarcoma cells K308 using cell-SELEX. All the dissociation constants of these aptamers against gliosarcoma cells were in the nanomolar range and aptamer WQY-9 has the highest affinity and good selectivity among them. Furthermore, truncated aptamer sequence, WQY-9-B, shows similar recognition ability to aptamer WQY-9. In addition, WQY-9-B was found to be able to bind selectively and internalize into cytoplasm of target cancer cell at 37°C. More importantly, compared to a random sequence, aptamer WQY-9-B showed excellent recognition rate (73.3%) for tissue sections of clinical gliosarcoma samples. These data suggests that aptamer WQY-9-B has excellent potential as an effective molecular probe for gliosarcoma diagnosis 3).
It is a highly invasive malignant tumor. Unfortunately, this disease still marked by poor prognosis regardless of modern treatments. It is of great significance to discover specific molecular probes targeting gliosarcoma for early cancer diagnosis and therapy.
In contrast to glioblastoma, it is characterised by its propensity for extracranial metastasis (11% of the cases) due to its sarcomatous component, most commonly spreading through the blood to the lungs, and also liver and lymph nodes.
An extensive analysis of the characteristics, treatments and outcomes of the gliosarcoma (GS) patients with central nervous system (CNS) metastases reported in literature until April 2013. PubMed and Web of Science searches for peer-reviewed articles pertaining to GBM/GS patients with metastatic disease were conducted using predefined keywords. Additionally, a hand search following the references from the selected papers. Cases in which the metastases exclusively occurred outside the CNS were excluded. 110 publications reporting on 189 patients were eligible. There was a significant increase in the number of reported cases over the last decades, with a median overall survival from diagnosis of metastasis (from initial diagnosis of GBM/GS) of 3.0 ± 0.3 (11 ± 0.7) months. On univariate analyses, gender, age, the histological subtype, the time interval between initial diagnosis and the occurrence of metastases and the location of CNS metastasis (intracranial versus spinal and parenchymal versus leptomeningeal, respectively) did not influence survival after diagnosis of metastasis. There was no substantial treatment progress over the recent decades. GBM/GS with CNS metastasis are associated with a dismal prognosis. Crucial treatment progress is not evident. A central registry should be considered to consecutively gain more information about the ideal therapeutic approach 4).
Hong et al. described 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 5).
A rare case of gliosarcoma arising from oligodendroglioma, isocitrate dehydrogenase (IDH) mutant and 1p/19q codeleted. A 36-year-old man presented with a non-enhanced calcified abnormal lesion on the right frontal lobe. The patient underwent subtotal surgical resection, PAV chemotherapy (procarbazine, nimustine (ACNU) and vincristine), and fractionated radiotherapy with 50 Gy. The pathological diagnosis was oligodendroglioma, IDH mutant and 1p/19q codeleted, World Health Organization 2016 grade II. Six years later, a new enhanced lesion appeared, and the recurrent tumor was surgically removed. Although the histopathological findings indicated gliosarcoma, the recurrent tumor still demonstrated the IDH mutation and 1p/19q codeleted. Thus, the recurrent tumor was considered to originate from oligodendroglioma, rather than being newly generated after chemoradiotherapy. Interestingly, the second recurrent tumor responded well to temozolomide chemotherapy. Based on the findings of this case, oligodendrogliomas have the potential for mesenchymal transformation on progression, while keeping their genotype 6).
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 7).
A 68-year-old male was hospitalized because of headache, nausea, and disturbance of consciousness. Neurological examination on admission disclosed somnolence, disorientation, marked neck stiffness, papilledema, and quadriparesis. Computed tomography (CT) scanning demonstrated a round mass with marked contrast enhancement in the right sylvian fissure and small contrast-enhanced masses in the interpeduncular, quadrigeminal and ambient cisterns. CT also showed marked peritumoral edema, a midline shift, and hydrocephalus. The patient’s consciousness level and respiration deteriorated 3 days after admission and a craniotomy was performed. The tumor, which was well demarcated, firmly attached to the sphenoidal ridge, and grossly appeared to be a meningioma, was totally removed. Histologically, the tumor had two well defined components, glioblastoma and fibrosarcoma. The patient underwent ventriculoperitoneal shunting, chemotherapy, and radiotherapy after surgery, but the primary tumor soon recurred, with scalp metastasis, and he died 5 months postoperatively. Autopsy revealed metastases to the liver, spleen, and spinal cord 8).
A report of array-based comparative genomic hybridization (aCGH) analysis of spinal gliosarcoma metastasis and the correlation to the clinical disease course shows that genotypic profiling may serve as a supplementary diagnostic tool in improving our knowledge of the biologic behavior of rare tumor variants 9).
Intramedullary gliosarcoma metastasis
Few 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 10) 11).