Suprasellar Meningioma Classification: Endoscopic Transnasal Perspective

Abstract

Objectives: Midline suprasellar meningiomas include planum sphenoidale, tuberculum sellae, and diaphragma sellae meningiomas. Over the past few decades, multiple classifications have been documented, but they have had controversial value and limitations, including their surgical implications. The aim of this study was to classify suprasellar meningiomas based on their behavior toward the underlying bone and neurovascular structures. Methods: Patients with newly diagnosed suprasellar meningiomas that underwent extended endoscopic transnasal approach (EETA) between 2015 and 2021 were included. Demographic data, clinical presentation, perioperative visual status, and preoperative radiological features were analyzed. Parameters evaluated are: chasmatic sulcus length, location of the optic chasim and nerves, optic canal involvement, and vascular displacement. Results: We identified 30 cases of midline suprasellar meningiomas; one diaphraghma sellae meningioma (Type A), 10 tuberculum sellae meningiomas (Type B), 9 chiasmatic Sulcus meningiomas (Type C), and 10 planum sphenoidale meningiomas (Type D). Asymmetrical visual complaints were most common in chiasmatic sulcus meningiomas, followed by tuberculum sellae meningiomas (66 and 50%, respectively). Chiasmatic sulcus meningiomas showed increased separation between the optic chiasm and the A1/A2 complex (8.9 mm) compared to tuberculum sellae (2.7 mm) and planum sphenoidale (1.9 mm) meningiomas. An increased chiasmatic sulcus length was also observed in chiasmatic sulcus meningiomas, compared to other types. Conclusions: Preoperative evaluation of bone involvement and tumor relation to neurovascular structures can be used to classify suprasellar meningiomas. Chiasmatic sulcus meningioma is a distinct subtype of suprasellar meningiomas. Its unique behavior towards nearby neurovascular structures could be of surgical value during tumor resection