Combined simultaneous transcranial and endoscopic endonasal resection of sphenoorbital meningioma extending into the sphenoid sinus, pterygopalatine fossa, and infratemporal fossa

BACKGROUND Sphenoorbital meningiomas are surgically challenging because of their nature to extend to adjacent structures. Here, we describe a case of recurrent sphenoorbital meningioma extending into the sphenoid sinus, pterygopalatine fossa, and infratemporal fossa, which was resected using combined simultaneous transcranial and endoscopic endonasal approaches. CASE DESCRIPTION A 62-year-old man who had 15 years earlier undergone partial resection of a left sphenoorbital meningioma presented with a 1-year history of progressive proptosis of the left eye. Magnetic resonance imaging (MRI) showed a Gd-enhancing tumor occupying the left sphenoid wing and orbital lateral wall and extending into extracranial structures such as the sphenoid sinus, pterygopalatine fossa, and infratemporal fossa as well as adjacent structures such as the cavernous sinus and superior orbital fissure (SOF). Based on the MRI findings of tumor extension into the sphenoid sinus with broad continuity, the risk of postoperative cerebrospinal fluid (CSF) leakage through the large defect in the sphenoid sinus was considered high. Subtotal resection using combined simultaneous transzygomatic and endoscopic endonasal approaches was performed, leaving residual tumor in the cavernous sinus and SOF. The large skull base defect between the middle fossa and sphenoid sinus was covered with a free graft of fascia lata from the transcranial side and with a vascularized nasoseptal flap from the endonasal side. No CSF rhinorrhea and no neurological deficits developed postoperatively. CONCLUSION Combined simultaneous transcranial and endoscopic endonasal approaches may become a safe and feasible alternative for sphenoorbital meningioma with a large skull base defect penetrating to the paranasal sinus.