Micrograph of a<unk>  showing the characteristic whorling, HPS stain Micrograph of a<unk>  with brain invasion (WHO Grade II). The tumour (bottom/right of image) has the typical "pushing border" invasion into the cerebral cortex (top/left of image), HPS stain.<unk> ta arise from arachnoidal cap cells, most of which are near the vicinity of the venous sinuses, and this is the site of greatest prevalence for<unk>  formation. Some subtypes may arise from the pial cap cells that migrate during the development together with blood vessels into the brain parenchyma. They most frequently are attached to the dura over the superior parasagittal surface of frontal and parietal lobes, along the sphenoid ridge, in the olfactory grooves, the sylvian region, superior cerebellum along the falx cerebri, cerebellopontine angle, and the spinal cord. The tumor is usually gray, well-circumscribed, and takes on the form of the space it occupies. They usually are dome-shaped, with the base lying on the dura. Locations * Parasagittal/falcine (25%) * Convexity (surface of the brain) (19%) * Sphenoid ridge (17%) * Suprasellar (9%) * Posterior fossa (8%) * Olfactory groove (8%) * Middle fossa/Meckel's cave (4%) * Tentorial (3%) * Peri-torcular (3%) *Intraparenchymal (rare) Other uncommon locations are the lateral ventricle, foramen magnum, and the orbit/optic nerve sheath.<unk> ta also may occur as a spinal tumor, more often in women than in men. This occurs more often in Western countries than Asian. Histologically,<unk>  cells are relatively uniform, with a tendency to encircle one another, forming whorls and psammoma bodies (laminated calcific concretions). As such, they also have a tendency to calcify and are highly vascularized.<unk> ta often are considered benign tumors that can be removed by surgery, but most recurrent<unk> ta correspond to histologic benign tumors. The metabolic phenotype of these benign recurrent<unk> ta indicated an aggressive metabolism resembling that observed for atypical<unk> .
Meningioma
Metastasis
Glioma
Solitary fibrous tumor
Hemangioblastoma
Lymphoma
Astrocytoma
Schwannoma