Central skull base meningioma.

Posterior clinoid process meningiomas are extremely rare lesions and comprise about 0.7% of central skull base meningiomas

Clinical and radiological features or characteristics of posterior clinoid process (PCP) meningiomas have rarely been described because of their extreme scarcity and terminological confusion.

Geng et al. subdivided the dorsum sellae meningiomas into two groups:

Type 1 (dorsum sellae, inferior third ventricle type)

Type 2 (dorsum sellae, third ventricular type), depending upon the site and direction of growth ^{1) 2) 3)}.

Lesions in this region are primarily of two anatomic types:

Centrally placed meningiomas located between the two posterior clinoid processes (PCPs) and arising from the dorsum sellae or upper clival region – which should be referred to as dorsum sellae or upper clival meningiomas.

Eccentrically placed meningiomas centered on the PCP are true posterior clinoid process meningiomas ⁴⁾.