Cranial Intraosseous Meningiomas: CT and MRI Findings.
Intraosseous meningiomas (IOMs) comprise a subset of primary extradural meningiomas and represent approximately two-thirds of all the extradural meningiomas. This study evaluated computed tomography (CT) and magnetic resonance imaging (MRI) findings of cranial IOMs. This study included ten patients (six females and four males) with IOMs who underwent cranial CT and/or MRI examinations during May 2009-June 2018. Lesions were classified based on the following locations: the sphenoid ridge, the calvarial convexity, other skull base bones, and the sphenoid ridge + calvarial extension. Bony extension, contour irregularity or radial bone spiculation, bony changes (hyperostotic, lytic, or mixed patterns), dural calcification, cerebral edema, and the presence of soft tissue were evaluated. Age of patients was 46-80 (mean: 55.30 ± 9.84) years. A total of eleven IOMs were identified in ten patients. Five of lesions were located in the sphenoid ridge + calvarium, three in the sphenoid ridge, two in the skull base, and one in the calvarial convexity. Nine lesions exhibited radial bone spiculation. Moreover, nine lesions exhibited hyperostotic CT pattern; while, two exhibited a mixed pattern. Three IOMs were accompanied with dural calcification, and peritumoral edema was observed in six IOMs. IOMs are predominantly low-grade tumors, commonly located in the periorbital area and often accompanied by soft tissue components and dural infiltrations. They most commonly lead to radial bone spiculation and bone expansion. Patients primarily have single lesions but may occasionally have multiple ones.