Extra-axial tumors

The msot common extra-axial neoplasm of adults.
Peak age 50-60 and women more commonly. Hormonally sensitive and may increase in pregnancy.
On CT see a well defined, hyperdense mass with variable surrounding edema and intense homogeneous enhancement on postcontrast studies. Can also see hyperostosis of the adjacent inner table.
MR: typically isointense to hypointense to gray matter on T1 and isointense to hyperintense on T2. (if bright on T2 is the angiomatous type)
CSF clefts around teh margin of the tumor confirm the extra-aaxial location.
Broad dural base and adjacent ddural thickening or "dural tail".

Peak incidence at 30 to 50
Arises from modified pericapillary smooth muscle cells
Associated with an aggressive biologic behavior and a high recurrence rate and shows a predilection for late distant mets.
Similar appearance to meningioma except has narrow base of attachment to the dura instead of broad base. Also multilobulated instead of being "hemispheric"
Bone destruction is also more ccommon.

Iinvolvement of the brain by systemic lymphoma is rare but when it occurs it much more commonly involves the leptomeninges.
May be hard to distinguish from a meningioma

Dural mets is most common form of extra axial spread.
Skull lesions, usually from breast, lung, prostate or renal CA give rise to epidural mets.