<unk>  is a relatively common neoplasm of the central nervous system that arises from arachnoidal cells which are normally involved in the protection of the brain and spinal cord by forming a thick envelope of meninges around them.<unk>  is the most common benign tumors of the brain. About 90% of<unk> s are benign with about 2% being malignant.<unk>  was first discovered by Dr Felix Platter, a Swiss physician, in the 16th century.<unk>  may be classified according to the histological criteria of the WHO. It is classified into 3 groups: benign classic<unk>  (WHO grade 1), atypical<unk>  (WHO grade 2), and anaplastic malignant<unk>  (WHO grade 3). Neurofibromatosis type II, cowden syndrome, and multiple endocrine neoplasia 1 are among a few conditions that are associated with<unk> . There are no established direct causes for<unk> .<unk>  must be differentiated from other diseases that cause similar presentation such as schwannoma, hemangiopericytoma, and solitary fibrous tumor. The incidence of<unk>  is approximately 7.62 per 100,000 individuals in the United States. The prevalence of<unk>  was estimated to be 97.5 cases per 100,000 individuals in the United States. Common risk factors in the development of<unk>  are history of radiation treatment, increasing age, and female gender. There is insufficient evidence to recommend routine screening for<unk> .<unk>  could present with complications such as peritumoral brain edema, stroke, and increased intracranial pressure. The hallmark symptom of<unk>  is headache. Other common symptoms of<unk>  include visual impairment, hearing loss/tinnitus, focal neurological deficits, behavioral changes. Head CT scan may be diagnostic of<unk> . Some of the findings on CT scan suggestive of<unk>  include edema, CSF attenuation cleft, round/elongated extraaxial mass, and hyperostosis of the adjacent skull.  MRI with gadolinium is the investigation of choice for the diagnosis of<unk> . On MRI,<unk>  is characterized by a homogeneous, well circumscribed, and extra-axial mass with a broad dural base. Other findings on MRI suggestive of<unk>  include CSF vascular cleft sign, dural tail sign, and central necrosis or calcification that do not enhance. In asymptomatic<unk> s, the decision of surgical resection must be weighed against the possibility of conservative management according to the patient's age, clinical presentation, and the anatomical location of the tumor. The predominant therapy for<unk>  is surgical resection. Current data suggest that both external beam radiotherapy and radiosurgery play an important role in the management of grade II and III<unk> s.
Meningioma
Glioma
Hemangioblastoma
Astrocytoma
Hemangiopericytoma
Ameloblastoma
Protoplasmic astrocytoma
Medulloblastoma