Fig. 2

Differential diagnosis between bone invasive meningioma and concomitant meningioma and CFD. a1, 2 typical CFD showing asymmetric expansive lesion at the left frontal bone with typical ground-glass matrix; b1, b2 hyperostosis caused by meningioma revealing a sclerotic lesion of the left greater sphenoid wing with spiculated margins; c1, c2 hyperostotic intraosseous meningioma with irregular inner table; d1, d2 concomitant meningioma and CFD