Endoscopic Endonasal Resection of Orbital Apex Schwannoma: A Case Report and Review of the Literature

Background To describe a rare case of orbital apex schwannoma—its presentation, diagnosis, initial treatment, and eventual surgical management. A review of the literature of orbital apex lesions was additionally performed

Case Report A 49-year-old woman who in May 2014 developed diplopia, headache, and right eye vision changes. On ophthalmoscope exam, her right optic nerve was swollen and edematous. Subsequent MRI of the brain revealed the lesion and right orbital apex mass. The patient was initially monitored with serial imaging; however, her symptoms progressed and the tumor was noted to be enlarging. She subsequently underwent a pterional craniotomy for optic nerve and orbital decompression. The tumor was not able to resect at that time. She received radiation after surgery in addition to oral steroid to curtail growth. Her vision and proptosis continued to worsen. She underwent endoscopic endonasal approach to right orbital apex and right medial orbital decompression with resection of the extradural orbital apex mass in a combined neurosurgical/otolaryngology procedure. Preoperative MRI demonstrated a T2 hyperintense well-demarcated mass measuring 1.2 × 0.5 cm centered at the right orbital apex abutting the optic nerve. Pathology was consistent with schwannoma. Postoperative MRI demonstrated low T1, heterogeneous T2 signal focus in the surgical bed with associated enhancement representing residual tumor. At the initial postoperative visit, the patient reported significantly improved proptosis with partial return of vision in her right eye. She is currently being followed with yearly imaging and routine clinical exam without evidence of tumor recurrence—her visual symptoms continue to incrementally improve.

Discussion In review of the literature, a variety of orbital apex lesions have been encountered. Lesions most commonly include cavernous hemangioma, squamous cell carcinoma, or fibrous dysplasia. However, there only three previously reported cases of schwannoma resection from the orbital apex utilizing a minimally invasive endonasal endoscopic approach. Multiple approaches to the orbital apex exist. Traditional open approaches include transconjunctival or frontotemporal craniotomy. In addition, a transmaxillary, transantral Caldwell–Luc’s approach has been described as an approach to the medial and inferior orbital apex. As endoscopic techniques improve, access to the orbital apex is increasingly achievable with skilled endoscopic technique. This particular case offers an excellent backing for the endoscopic approach. The endonasal route offered an alternative for a previously operated and radiated patient. Most importantly, the patient’s vision was markedly improved after resection.

Conclusion This is a description of a rare orbital neoplasm. The case reports offer an excellent example for the versatility of endoscopic endonasal surgical approach for surgical management of orbital apex neoplasms.