Gliosarcoma is a rare type of

glioma A glioma is a type of primary tumor that starts in the glial cells of the brain or spinal cord. They are malignant but some are extremely slow to develop. Gliomas comprise about 30% of all brain and central nervous system tumors and 80% of ...

, a

cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...

of the brain that comes from

glial Glia, also called glial cells (gliocytes) or neuroglia, are non-neuronal cell (biology), cells in the central nervous system (the brain and the spinal cord) and in the peripheral nervous system that do not produce Action potential, electrical ...

, or supportive, brain cells, as opposed to the

neural In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes t ...

brain cells. Gliosarcoma is a malignant cancer, and is defined as a

glioblastoma Glioblastoma, previously known as glioblastoma multiforme (GBM), is the most aggressive and most common type of cancer that originates in the brain, and has a very poor prognosis for survival. Initial signs and symptoms of glioblastoma are nons ...

consisting of gliomatous and

sarcoma A sarcoma is a rare type of cancer that arises from cells of mesenchymal origin. Originating from mesenchymal cells means that sarcomas are cancers of connective tissues such as bone, cartilage, muscle, fat, or vascular tissues. Sarcom ...

tous components. Primary gliosarcoma (PGS) is classified as a grade IV tumor and a subtype of glioblastoma multiforme in the 2007 World Health Organization classification system (GBM). Because of a lack of specific and clear diagnostic criteria, the word "gliosarcoma" was frequently used to refer to glial tumours with mesenchymal properties, such as the ability to make collagen and reticulin.Feigin I, Gross SW (1954) Sarcoma arising in glioblastoma of the brain. Am J Pathol 31:633–653 It is estimated that approximately 2.1% of all glioblastomas are gliosarcomas. Although most gliomas rarely show metastases outside the

cerebrum The cerebrum (: cerebra), telencephalon or endbrain is the largest part of the brain, containing the cerebral cortex (of the two cerebral hemispheres) as well as several subcortical structures, including the hippocampus, basal ganglia, and olfac ...

, gliosarcomas have a propensity to do so, most commonly spreading through the blood to the

lungs The lungs are the primary organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the backbone on either side of the heart. Their function in the respiratory syste ...

, and also

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

and

lymph nodes A lymph node, or lymph gland, is a kidney-shaped Organ (anatomy), organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphoc ...

. They most commonly present in the

temporal lobe The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe is involved in pr ...

and

frontal lobe The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a Sulcus (neur ...

Pathogenesis

Early reports claimed that the hyperplastic blood vessels that are frequently present in high grade gliomas underwent neoplastic change to become the sarcomatous components. Feigin's early reports components of perivascular sarcomatous and hyperplastic arteries in gliosarcoma offered evidence for the "collision tumor" hypothesis. Also, Studies demonstrating the sarcomatous component's histological sensitivity to markers of vascular endothelium such factor CD34, von Willebrand factor, and VIII supported this theory. An alternative view that has recently gained support suggests that both gliosarcoma components have a monoclonal origin, with the sarcomatous component deriving from abnormal differentiation of malignant gliomal mesenchyma. First, gliomatous and sarcomatous components were shown to have similar p53 alterations by Biernat and colleagues. In both tumor regions, Reis and colleagues found similar nuclear accumulation of p53, deletion of p16, mutations of PTEN,and amplifications of CDK4. Other scientists then noted that both gliosarcoma components had similar genetic changes and chromosomal abnormalities of the kind often seen in GBM.

Clinical characteristics

Gliosarcoma is rare; incidence ranges from 1.8 to 2.8 percent lower than that of GBMs. Lutterbach J, Guttenberger R, Pagenstecher A (2001) Gliosarcoma: a clinical study. Radiother Oncol 61:57–64 PGS affects persons in their 6th to 7th years of life, and it is much more frequent in males than in females (with 1.4-1.8:1 ratio). Depending on where the tumor is located, the reported presenting signs and symptoms, such as aphasia, headaches, hemiparesis, seizures, and cognitive loss, are similar with those of a fast developing intracranial tumor. Many researchers have come to the conclusion that these tumors are clinically identical to GBM due to their clinical similarities.

Imaging

On CT imaging, the lesions might show as Well-defined high-density lesion edges and homogeneous enhancement, replicating the meningioma appearance, or as lesions with large necrotic regions and GBM-like heterogeneous contrast enhancement. Marked peritumoral edema is a characteristic and frequent hallmark of gliosarcomas observed on MRI.

Metastasis

GBM and other cerebral gliomas rarely metastasize outside the brain. Numerous authors described incidences of metastatic foci that mixed gliomatous and sarcomatous components, while others reported metastatic foci that were entirely composed of the sarcomatous component. Most gliosarcoma extracranial metastases are found in the lung and liver, but there have been reports of metastases elsewhere as well, including evidence of intramedullary metastases to the cervical spine.

Treatment

Tumor removal, postoperative radiation treatment, and chemotherapy with nitrosureas, misonidazole, dacarbazine, temozolomide, doxorubicin , vincristine, cisplatin, mithramycin, ametophterin, thalidomide, or irinotecan have all been recorded as treatment options for gliosarcoma and radiotherapy with temozolomide.

Prognosis

PGS has a poor prognosis, a prognosis of median survival of 4 months in untreated individuals. Morantz R, Feigin I, Ransohoff J (1976) Clinical and pathological study of 24 cases of gliosarcoma. J Neurosurg 45:398–408 The

National Cancer Institute The National Cancer Institute (NCI) coordinates the United States National Cancer Program and is part of the National Institutes of Health (NIH), which is one of eleven agencies that are part of the U.S. Department of Health and Human Services. ...

states that the relative

five-year survival rate The five-year survival rate is a type of survival rate for estimating the prognosis of a particular disease, normally calculated from the point of diagnosis. Lead time bias from earlier diagnosis can affect interpretation of the five-year surv ...

of gliosarcoma is only 5.6%.

References

External links

Gliosarcoma
entry in the public domain NCI Dictionary of Cancer Terms
Gliosarcoma - National Cancer Institute
{{Central nervous system tumors Rare cancers Brain tumor