**4. Diagnosіs**

Despite the fact that advanced imaging techniques are more accessible and have advantages in certain scenarios, the computed tomography and MRI routine scans remain the standard investigations for patients with MAC [28]. Hyperostosis, bone structures, and anatomical syntopy could be assessed with standard protocols. CT is informative in assessing the bony structures of the skull base, especially anterior clinoid hyperostosis, as well as to determine the presence of petrifications in the tumor. This examination is routinely performed the next day after surgery to control the extent of the tumor removal and exclude the hematoma.

Some features are associated with more aggressive meningiomas and include increased signals on both T1- and T2-weighted MRI, irregular contour, extensive edema, lack of calcifications, central necrosis, and low apparent diffusion coefficient [29]. However, if normal anatomy is variable, the more challenging pathological anatomy influenced by the tumor makes the strategy individual.

Attention should be paid to the tumoral entrapment of the supraclinoid part of the ICA. The ICA is "enveloped" and can *potentially* be dissected from the tumor if the tumor does not invade the bone, CS, and grows expansively in the intracranial direction. Circular encasement of the ICA by the tumor that spreads from the CS along the artery makes its surgical separation almost impossible [30].

Thus, we tend to divide MAC into two main types. The first includes tumors that do not invade the anterior clinoid process and grow expansively into the cranial cavity. Type II meningiomas involve the ACP, spread into the CS, and concentrically entrap the supraclinoid segment of the ICA. There is a sense to separate the second subgroup of tumors: with the penetration to the CS and without it. Anatomical criteria for distribution are demonstrated in **Table 1** and **Figures 2**–**4**.


#### **Table 1.**

*Criteria for distribution of sphenoid meningiomas.*

**Figure 2.** *Type I sphenoid meningioma.*

**Figure 3.** *Type IIA sphenoid meningioma.*

**Figure 4.** *Type IIB sphenoid meningioma.*

Many surgeons recommend performing angiography before surgery to determine the tumor's blood supply and venous features. We totally agree with the expediency of this study, however, we would not insist on the absolute need to conduct it to all patients with this pathology.
