Intraosseous intracranial meningioma

Abstract

Primary intraosseous lytic meningiomas are rare tumors, with only 16 cases described in the literature. We present a case in which CT and MR imaging with contrast agent helped diagnose preoperatively an enlarging skull mass as a primary intraosseous lytic meningioma in a 70-year-old woman. Radiographic findings revealed a lytic mass centered on the coronal suture line that separated and thinned both the outer and inner tables of the frontal bone.

Fig 1.

A, Noncontrast CT axial projection of a 41-mm minimally hyperattenuated homogeneous lytic mass centered at the coronal suture line with the inner and outer bony tables thinned and partially interrupted. B, Bone window exhibiting an osteolytic lesion with anterior hyperostosis. C, Axial T1-weighted precontrast MR image demonstrating an isointense biconvex mass. D, Axial T1-weighted postcontrast MR image demonstrating intense homogeneous enhancement with a mild dural reaction.

Fig 2.

Intraoperative image demonstrating an exophytic relatively vascular skull mass.

Fig 3.

A, Light microscopy (H&E; original magnification × 2) of resected tumor involving bone. B, Light microscopy (H&E; original magnification × 40) reveals sheets of small cells with uniform nuclei forming small whorls.