الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Anterior skull base is the plane over both orbits and paranasal sinuses, multiple benign and malignant varieties of anterior cranial fossa tumors arc encountered. Tumors may originate from the base itself or from structures below or above the plan of anterior skull base. These tumors may invade the base through weak cribriform plate of ethmoid bone. The most common extra axial neoplasms in the anterior skull base are meningiomas, which have characteristic anatomic locations. As skull base tumors are derived from different embryological compartments, including glandular, epithelial, neural, ectodermal, and mesenchymal tissues so, many other neoplasms are encountered as haemangioma, fibrous histiocytoma and olfactory schwannoma. Anterior cranial fossa neoplasms are more common in females. The age was between 27-73 years for all cases, with the mean age (53.5 years) The initial subjective symptom is usually headache which is typical of increased intracranial pressure in most cases. Some tumors especially olfactory groove rneningiomas may be discovered late when the tumor size becomes large allowing compression of some important structures as optic nerve and chiasm so, diminished vision either unilateral or bilateral with or without field defect, is another important symptom especially in deep sphenoid and tuberculum sellae types. Another important symptom unique the olfactory groove meningiomas is anosmia. This complaint may pass unoticed in some patients. Less common clinical symptoms was found like frontal manifestations, diplopia, focal neurological deficit, and nasal complaint in tumor arising from nasal sinuses. MRI brain is the most useful diagnostic modality for diagnosis, evaluation, differential diagnosis and follows up of patients having anterior skull base extra axial neoplasm. CT scan is more sensitive in demonstrating skull base bony details. Preoperative angiography is important in delineating the displacement and narrowing of the internal carotid artery and its branches. Also, it is helpful in preoperative embolization. MRA is non invasive and also can dlineate the position and state of the neighboring vessels-There are many approaches to deal with anterior skull base extra axial neoplasms, according to the pathology and location of the lesion. Medline anterior skull base neoplasm extending to suprasellar area can be approached using anterior transcranial corridor. Tumors involving the facial skin with extension into the paranasal sinus region and skull base can also be encompassed by an anterior transfacial approach. While the anterolateral corridor is one of the most common routes through which sphenoid ridge, suprasellar and olfactory groove tumors can be approached. The only definitive cure for meningiomas is complete surgical resection. The more complete the resection, the less chance of recurrence. Malignant tumors need early radical resection via combined approaches with safety margins. Postoperative radiotherapy is helpful in these cases. Newer techniques in reconstruction, improvement of neuroanaesthesia, adjuvant therapy, intensive postoperative care and rehabilitation methods has dramatically improved the outcome of these cases Key considerations in meningioma surgery include; early CSF drainage, minimal brain retraction, keeping always limited to arachnoid plane, early cutting tumoral blood supply, doing an extensive internal decompression for large tumors, retracting the tumor capsule into the area of decompression to keep traction on the frontal lobes to a minimum and lastly careful separation of the tumor from attachments to optic nerves and anterior cerebral arteries. The use of microsurgical techniques considerably widens the possibilities for surgical treatment of anterior skull base neoplasm and makes it possible to be successfully removed.