Intraosseous Meningiomas

Abstract

Meningiomas limited primarily to the bone (intraosseous or intradiploic meningiomas) are rarely seen [8, 17]. Since the term meningioma was introduced and popularized by Cushing in 1922 [4] there have been sporadic reports of intraosseous meningiomas involving the temporal bone [2, 6, 9, 11, 12], bony orbit [5, 7, 14, 15, 18], and other areas of the skull [1, 10, 13, 16, 18]. These tumors are extremely rare, but no age group is spared -a case was reported in a 7-month-old child [3]. The frequency of intraosseous meningiomas is not known exactly. Cushing in his classic monograph of meningiomas did not mention any such case [4], and the frequency of primary intraosseous meningiomas has not been reported in any major neurosurgical series. In the course of their growth intraosseous meningiomas may eventually thin out and break through the bone (just as subdural meningiomas invade bone by breaking through the dura), adding an extraosseous portion to their mainly in traosseous tumor, and may eventually infiltrate the dura locally. Their primary intraosseous origin may be inferred from the location of the main tumor mass and from the very limited dural invasion [1, 18].