- Department of Neurosurgery, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
- Department of Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
DOI:10.4103/2152-7806.63910© 2010 Prabhu SS This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
How to cite this article: Prabhu SS, Bruner JM. Large oculomotor schwannoma presenting as a parasellar mass: A case report and literature review. Surg Neurol Int 31-May-2010;1:15
How to cite this URL: Prabhu SS, Bruner JM. Large oculomotor schwannoma presenting as a parasellar mass: A case report and literature review. Surg Neurol Int 31-May-2010;1:15. Available from: http://sni.wpengine.com/surgicalint_articles/large-oculomotor-schwannoma-presenting-as-a-parasellar-mass-a-case-report-and-literature-review/
Background:Large schwannomas arising from the oculomotor nerve are very rare. The common site of tumor occurrence in this nerve is the segment within the interpeduncular cistern and the cavernous sinus.
Case description:We report a case of a large left-sided oculomotor nerve schwannoma with minimal clinical signs and symptoms of oculomotor nerve involvement resembling a large parasellar mass. The radiological features of the mass were more consistent with a medial sphenoid wing meningioma causing brain stem compression. Complete resection of the tumor was achieved via a left pterional approach. The patient developed complete third nerve palsy postoperatively.
Conclusion:The management of these large benign tumors with brain stem compression includes surgical resection. Intraoperative anatomical preservation of the third nerve was impossible given its course in the tumor. We discuss the pertinent literature and management of large oculomotor schwannomas.
Keywords: Meningioma, oculomotor schwannoma, skull base
Schwannomas constitute about 7% of all intracranial tumors and commonly arise from the vestibulocochlear and trigeminal nerves. Motor nerve schwannomas arising from the oculomotor nerve are very rare. Approximately 30 cases of oculomotor nerve schwannomas have been described in the literature, of which 11 cases were described as large (≥2.5 cm). The management of these large tumors is especially challenging given the relationship of these tumors to the cranial nerves and the brainstem. Here we report a large oculomotor schwannoma and review the management of these uncommon tumors.
A 38-year-old female developed symptoms of headache, dizziness, occasional diplopia and drooping of the left eyelid. Imaging confirmed a large left suprasellar mass (3.5 cm in diameter) with midbrain compression, suggesting a meningioma [Figures
An axial gadolinium-enhanced contrasted T1-weighted MRI scan showing a large parasellar/ suprasellar mass with significant brainstem compression (a ). A postoperative axial gadolinium-enhanced T1-weighted MRI contrast scan 3 months later showing a complete resection of the mass with brainstem compression reversed (b)
A coronal gadolinium-enhanced contrasted T1-weighted MRI scan showing a large parasellar/ suprasellar mass with significant brainstem compression (a). A postoperative coronal gadolinium-enhanced T1-weighted MRI contrast scan 3 months later showing a complete resection of the mass with brainstem compression reversed (b). A combined subtemporal and anterior Sylvian fissure-splitting approach was used to reach the tumor
Pathologic description: Multiple rubbery fragments of tumor aggregated to a mass about 3.5 cm in diameter. Multiple histologic sections showed typical appearance of a benign schwannoma with short-spindled cells and random nuclear pleomorphism [
Schwannomas arising from the ocular nerves are extremely uncommon, unless associated with neurofibromatosis. Kovacs,[
Of the 12 patients (including our patient), there were 9 females and 3 males with a median age of 41.5 years. Celli et al.[
Seven (58%) out of 12 patients underwent a complete resection[
Hiscott and Symon[
Oculomotor nerve reconstruction may be important for cosmetic reasons (to avoid ptosis) and in cases involving blindness in the other eye. Nerve grafting, tried after resection of smaller tumors, produces only partial recovery.[
Large schwannomas of the third cranial nerve are a rare entity and are frequently misdiagnosed as meningiomas on preoperative imaging because of the paucity of clinical signs and symptoms of cranial neuropathies. Although a significant number of these patients are left with complete third nerve palsy following surgical intervention, gross total resection of these tumors is recommended for treatment or prevention of brainstem compression. The patients need to be adequately counseled regarding the high morbidity from third nerve palsy associated with resection of these tumors.
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