Lateral Sphenoid Wing Meningiomas

Abstract

Lateral sphenoid wing meningiomas may exhibit two patterns of growth. One is globular, and a tumor showing this type of growth is, from a surgical standpoint, a low convexity meningioma, which is not discussed here further. The other is an en plaque type of growth, almost invariably with diffuse bone and dural invasion. These tumors tend to have a small intradural component, a wide dural component, and an even wider bony extension. As noted by Cushing, they tend to invade the greater wing of the sphenoid both in its lateral component, that is, the posterior portion of the lateral orbital wall, and in its medial component, the anterior portion of the middle cranial fossa and the posterior orbital wall [2]. It can be seen that they may invade the orbit both from its posterior and from its lateral wall. Their orbital invasion may be confined to the periorbita, representing the continuation of the outer dural layer, or extend to the dural layer of the optic nerve, representing the continuation of the inner part of the dura.