**6. Classification**

Despite their common features, SOMs are a heterogeneous group of tumors due to the complex anatomy of the sphenoid bone, which is a part of both the skull base and the orbit. Few attempts have been made to classify SOMs. Roser *et al.* approached the classification of SOMs by first identifying the morphology of the meningioma (globoid, *en plaque,* and purely intraosseous), then detailing the involvement of the sphenoid wing and the CS [17]. Kong *et al.* in turn proposed a slightly simplified version, focusing on the location of the tumor epicenter at the level of the greater wing of the sphenoid bone, which they divided into three thirds (medial, middle, and lateral) [18]. We suggest our own classification system derived from the previous schemes. Our proposed classification system successively takes into account the general morphology of the meningioma, its epicenter in the sphenoid wing, and the tumor invasion of specific anatomical regions and structures (**Figure 4**). These three main parameters are intended to assist in the surgical strategy planning by helping surgical teams determine the anatomical targets, how to reach them, and how to decompress them.

#### **Figure 4.**

*Classification of spheno-orbital meningiomas according to their morphology (a), sphenoid wing epicenter (b), and specific extensions (c).*
