Endoscopic Endonasal Multimodular Approach for Resection of Concomitant Trigeminal Schwannoma and Pituitary Adenoma: A Single Corridor for Different Pathologies

Background Trigeminal schwannomas (TS) represent significant challenge in their surgical management due to their anatomical diversity, and the varied relationship with multiple cranial nerves along different skull base compartments. They can originate anywhere along the trigeminal nerve root, ganglion, or nerve branches. Different skull base approaches have been described for attacking TS, depending on their anatomical location and extension. Endoscopic endonasal approach (EEA) has been described previously as a minimally invasive, yet effective, option for surgical management of TS existing in the Meckel’s cave, pterygopalatine fossa, and infratemporal fossa. There are few reports of intrasellar TS; however, concomitant TS and pituitary adenoma (PA) have not been reported. To the best of our knowledge, we report the first case of concomitant TS and PA, where the two lesions were resected via a single approach through endoscopic endonasal corridor.

Case Description A 39-year-old man presented for consultation regarding TS with concomitant PA that were diagnosed and observed since he was asymptomatic. He started to have blurred vision 7 years later. Visual field examination demonstrated superior bitemporal defects. Physical examination revealed numbness and hypoesthesia in V2 and V3 distribution, and decreased tonus in right masseter muscle. The rest of his neurological examination was unremarkable. MRI of the brain was obtained which revealed progressive increase in the size of both lesions with considerable brain edema and mass effect on the optic apparatus. Since TS was located mainly in the Meckel’s cave, middle cranial fossa, and infratemporal fossa, the option of EEA for resection of both lesions was discussed with the patient and he opted for surgery. EEA was performed with combination of different modules in sagittal and coronal planes to achieve the maximum degree of exposure and resection of both lesions. The PA was addressed first via transsellar approach. The TS was resected via transpterygoid and infratemporal fossa approaches. We achieved complete extracapsular resection of the PA and subtotal resection of the TS. There were no intraoperative complications. The postoperative course was uneventful except for a single episode of seizure that was related to hyponatremia, and it was well controlled. Histopathological examination confirmed the diagnosis of TS and null-cell type PA. At 4 months follow-up, visual field examination showed improvement of preoperative field defects. At 5 years follow-up, the patient was doing very well with no new neurological deficits, and MRI of the brain demonstrated complete resection of the PA along with stability of the residual portion of the TS with no progression in size.

Conclusion EEA can be deemed an effective and safe option for surgical resection of TS involving the Meckel’s cave, pterygopalatine fossa, and/or infratemporal fossa. EEA provides an excellent corridor for resection of multiple pathologies affecting the ventral skull base, through combination of different surgical modules in the sagittal and coronal planes.

No conflict of interest has been declared by the author(s).