الفهرس 
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Abstract
Meningiomas are the most common primary brain tumor and comprise nearly one-third of all newly diagnosed primary brain tumors. Meningiomas are thought to be arachnoid cap cell derived and are dural (intracranial extraparenchymal) in location. Meningiomas are most common in the elderly although they occur at all ages, majority of patients are female (there is a 60:40 female to male ratio in intracranial meningioma).The prevalence of Meningioma is estimated to be ~97.5/100,000 in the United States, with more than 160,000 individuals currently diagnosed with this tumor (Rogers L, et al. 2015).
The majority of meningiomas are supratentorial, with a large number located along the convexities. Approximately 17 to 25% occur in a frontobasal location; however, only about 10% occur in the posterior fossa. Within the frontobasal region, the olfactory grooves, tuberculum sellae and parasellar region, and the petrous bone are preferred sites. Approximately 5% occur along the cerebellar convexity, 2 to 4% at the tentorium cerebelli and 2 to 4% within the cerebellopontine angle. Uncommonly, meningiomas are found within the ventricular system or arise within the optic nerve sheath (Buetow MP, et al. 1991).
Meningiomas of the suprasellar region involving the tuberculum sellae, anterior clinoid processes, diaphragma selae, and planum sphenoidale are rare tumors that have proved difficult to treat, partly because of their intimate association with the optic nerves and chiasm, hypothalamus, and internal carotid arteries (Zhao-Feng Lu et al ,2013).
The advances in diagnostic techniques and instrumentation have led to an increase in the identification of incidental meningiomas which account for almost half of the meningiomas diagnosed in the growing elderly population. The intimate relationship between Supra-sellar meningiomas and the optic apparatus characterizes the clinical picture of chiasmatic syndrome (visual field defect).
Other clinical symptoms usually correlate with the size of the tumor and its extension. Extension of the tumor into the cavernous sinus region may result in associated cranial neuropathies (Kuratsu J, et al. 2000).
Occasionally some of the tumors extend to the middle temporal fossa and may enlarge laterally to compress the temporal lobe, resulting in seizures, or may even compress the brain stem, resulting in hemiparesis (Kuratsu J, et al. 2000).
Recent years have witnessed the development of advanced imaging techniques, such as MR spectroscopy, MR perfusion and positron emission tomography (PET), which at times aid in the diagnosis of meningiomas. Although these studies are becoming more standardized and their usefulness in certain clinical scenarios better defined, these newer techniques remain peripheral at present and serve only as adjuncts to CT and routine MRI sequences (Rockhill J, et al. 2011).
Approximately 85 to 90% of meningiomas have typical features, including an extra-axial mass with signal intensity isointense to cortex on T1 and T2 MRI sequences, homogeneous enhancement following administration of gadolinium contrast, and an enhancing “dural tail” , which reflects neoplastic dural infiltration or reactive vascularity (or both) draining into the adjacent dura (Rockhill J, et al. 2011).
The goal of treatment cannot be more eloquently stated than the words of Cushing: “There is today nothing in the whole realm of surgery more gratifying than the successful removal of a meningioma with subsequent perfect functional recovery. (Nevo M., et al. 2013).
One must admit that not every meningioma can be removed totally, and the surgeon is forced in some cases to accept residual tumor, but it should be the surgeon’s goal to attempt a total removal while preserving or improving the patient’s neurological function (Nevo M. et al. 2013).
The ideal surgical approach should provide enough exposure of the tumor and the surrounding structures, including its dural attachment, to interrupt its blood supply early in the procedure (Saul F, et al., 2014).
Many different surgical approaches have been described for the resection of supra-sellar and para-sellar lesions. The common approaches include pterional, fronto-lateral approaches and its modifications (Saul F, et al., 2014).
In those patients where surgical cure is not anticipated or the risks of new neurologic deficits seem excessive, Gamma knife radiosurgery represents an important therapeutic option (Douglas A, et al., 2013).