What Is Gliosarcoma?
Gliosarcoma is a primary central nervous system (CNS) tumor, including the brain and spinal cord. Glial cells of the brain are a type of central nervous system cell that is affected by this tumor. These cells are not nerve cells, but they maintain, nourish, and protect nerve cells in the brain and spinal cord. A biopsy of a small part of the tissue is performed to get an accurate diagnosis. A neuropathologist should then examine the tumor tissue.
How Are Gliosarcomas Classified?
Central nervous system tumors are classified depending on the following factors:
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Nature.
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Location.
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Genetic findings.
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The patient's age.
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The extent of dissemination.
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The amount of tumor that remains after surgery.
Gliosarcomas are all considered Grade IV tumors. This indicates that they are malignant and cancerous and rapidly expanding tumors. They are further classified as:
Primary: The tumor develops after the initial surgery or biopsy.
Secondary: The tumor develops from a pre-existing glioma following radiation therapy.
What Is the Etiology of Gliosarcomas?
Cancer is a genetic illness caused by genetic alterations regulating the cell's work. Genes can be mutated or altered in many types of cancer, leading to cancer cell formation and spread. The majority of gliosarcomas have no recognized etiology. However, previous radiation exposure and specific gene abnormalities passed down through families have increased the risk of glioblastomas.
What Is the Incidence of Gliosarcomas?
Gliosarcomas are most commonly detected on the brain's surface and spinal cord. Glial cells, which are brain support cells, give rise to them. Some are similar to astrocytes and star-shaped glial cells. Sarcomas are connective tissue cancer. It is usually seen in the cerebral hemispheres, particularly the frontal and temporal lobes. In rare cases, it can also be detected intraventricularly. It has a preference for males between the ages of 40 and 60. If it is not treated, it has a poor clinical result, with an average survival of fewer than six months.
What Is Infantile Gliosarcoma?
Gliosarcoma in a newborn is a malignant primary brain tumor that accounts for 1.8-8 percent of glioblastomas. The malignant transformation of cells in the blood vessels of a pre-existing multiforme is thought to cause gliosarcoma. Most gliosarcoma instances in young children are of the sarcoglioma type, a tumor formed of a central core of sarcoma with peripheral dispersion of gliomatous features and a progressive shift from reactive to neoplastic astrocytes.
What Are the Symptoms of Gliosarcoma?
The symptoms of gliosarcomas vary depending on where the tumor is located. However, the following are the symptoms of gliosarcoma:
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Numbness.
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Headaches.
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Weakness.
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Balance and mobility issues.
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Problems with thinking or remembering.
How Are Gliosarcomas Diagnosed?
Magnetic Resonance Imaging -
Gliosarcomas often manifest as solitary tumors with hazy margins. However, tumors can form near the brain's surface, and multiple tumors can develop in various locations. Gliosarcomas often manifest as solitary tumors with hazy margins. Tumors can form near the surface of the brain and get adhered to the brain's covering. The tumor frequently brightens with contrast, and multiple tumors can develop in various locations of the CNS. Gliosarcomas are frequently accompanied by edema.
Computed Tomography -
The lesions may present on CT imaging as well-defined high-density lesion edges with enhancement, mimicking the appearance of a meningioma (another type of tumor of the brain and the spinal cord), or as lesions with vast necrotic zones and GBM (glioblastoma) -like heterogeneous contrast enhancement. Peritumoral edema (swelling around the layers of the brain) is a common and typical feature of gliosarcomas shown on MRI.
What Is the Treatment of Gliosarcomas?
The patient's healthcare team decides on treatments depending on the patient's age, tumor location, and residual tumor after surgery.
Surgery -
It is the initial line of therapy for gliosarcoma. It aims to gather tissue to diagnose the kind of tumor and remove as much tumor as possible without exacerbating the patient's symptoms. As gliosarcomas are aggressive, most patients undergo various other therapies too.
Radiation -
A high total dosage of radiation (minimum dose of 54 Gy) is associated with better overall survival in people.
Chemotherapy -
Various chemotherapeutic drugs have been utilized in treating gliosarcoma, and multiple studies have been undertaken. Chemotherapeutic agents, such as Cisplatin, Lomustine, and Cytarabine, are beneficial.
Bevacizumab -
Bevacizumab is a recombinant (93 percent human) monoclonal IgG1 antibody that binds to VEGF (vascular endothelial growth factor) receptors on endothelial cells. This interaction reduces endothelial cell growth and the development of new vessels. Gliosarcoma is a promising target for bevacizumab therapy because it is a highly vascularized tumor that produces pro-angiogenic factors.
Temozolomide -
It is part of a therapeutic regimen for people with gliosarcoma.
Does Gliosarcoma Metastasize to Other Organs?
Although it is uncommon, gliosarcoma can cause extracranial metastasis. Extracranial metastasis has been documented in roughly 0.5 percent of malignant glioma patients. There are various theories as to why extracranial metastases of high-grade glioma are uncommon. The average survival duration for high-grade gliomas ranges from 6 to 14.8 months. Because metastasis is uncommon, systemic staging imaging scans are not standard. Thus, extracranial metastases may be more common but not detected before deadly brain herniation.
Another explanation is that the absence of a lymphatic system within the brain and spinal cord and the tight dura surrounding intracranial veins are intrinsic biological impediments that prevent tumor cells from entering and surviving outside the neural environment.
The liver, vertebrae, lungs, and lymph nodes are the most common sites of extracranial metastases. Furthermore, metastasis in the scalp, spleen, skin, paranasal sinuses, small intestine, eyes, pancreas, parotid gland, pleura, kidneys, bone, and peritoneum has been observed.
What Is the Prognosis of Gliosarcomas?
Gliosarcoma has a 5-year relative survival rate of 5.6 percent. However, various variables might alter the prognosis. This includes the grade and kind of tumor, the person's age, cancer features, health at the time of diagnosis, and how they respond to therapy.
Conclusion:
Gliosarcoma is a rare histological form of glioblastoma with prominent mesenchymal differentiation. The sarcomatous differentiation includes the formation of bone, cartilage, or epithelial metaplasia (transformation of one cell type to another). Gliosarcoma is a histological biphasic tumor with discrete glial cells. It is a highly unusual clinicopathological disease. It is linked to an aggressive clinical course, with people rapidly deteriorating and having dismal results.
