Skull-Base Chordoma Mimicking Optic Neuritis

Clinical Correspondence Section Editors: Robert Avery, DO Karl C. Golnik, MD Caroline Froment, MD, PhD An-Guor Wang, MD Skull-Base Chordoma Mimicking Optic Neuritis Abdullah A. Ali, MD, Fatmah Dashti, FFR-RCSI, Raed S. Behbehani, FRCSC C hordoma is a slow-growing tumor which comprises approximately 1% of intracranial tumors, with 35% arising from the skull base and 0.1%–0.2% of the intracranial neoplasms located within the sellar region. The tumor originates from cell remnants of the primitive notochord and usually becomes symptomatic between the third and fifth decade. The neuroophthalmic manifestations of chordoma include diplopia due to cranial nerve palsy and visual loss due to optic nerve or chiasmal compression (1). The authors describe a patient with chordoma of the seller region with an atypical presentation of rapid monocular visual loss associated with pain, mimicking optic neuritis. A 37-year-old woman presented with a 1-week history of visual loss in the left eye associated with pain worsening with eye movement. She had no other neurologic symptoms such as paresthesia, limb weakness, or diplopia and no significant medical or ophthalmic history. Visual acuities were 20/20 in the right eye and 20/400 in the left eye, and she recognized 13 of 13 Ishihara color plates in the right eye and none in the left eye. Pupillary testing showed a prominent left relative afferent pupillary defect. The intraocular pressure was 18 mm Hg in both eyes, and her anterior segment examination was normal in both eyes. Ocular motility testing showed that she was orthotropic with full ductions and versions in both eyes. Fundus examination showed normal-looking optic discs in both eyes. Automated visual field testing (Automated 24–2, Carl Zeiss, Dublin, CA) was normal in the right eye and showed generalized total depression in the left eye (See Supplemental Digital Content, Figure 1, http://links. lww.com/WNO/A674). The patient was initially diagnosed with left optic neuritis based on her clinical presentation. However, a MRI of the brain with contrast showed a central skull-base mass with high signal intensity Al-Bahar Ophthalmology Center (AAA, RSB), Ibn Sina Hospital, Kuwait City, Kuwait; and Department of Radiology (FD), Ibn Sina Hospital, Kuwait City, Kuwait. The authors report no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www. jneuro-ophthalmology.com). Address correspondence to Abdullah A. Ali, MD, Al-Bahar Ophthalmology Center, Ibn Sina Hospital, P.O Box 1180, Kuwait; E-mail: [e-mail] Ali et al: J Neuro-Ophthalmol 2023; 43: e219-e220 on T2 and low T1 signal intensity with multiple punctate nonenhancing foci encroaching more on the left optic nerve and chiasm. There were no signal changes in the intraorbital or intracranial optic nerve suggestive of inflammation (Fig. 1). Spectral domain optical coherence tomography (Topcon 2000 3D OCT, Tokyo, Japan) of the optic disc showed normal retinal nerve fiber layer (RNFL) thickness in both eyes (See Supplemental Digital Content, Figure 1, http://links.lww.com/WNO/A674). Although the patient was initially diagnosed with optic neuritis, intravenous methylprednisolone was not administered. Transsphenoidal resection of the mass was subsequently performed to decompress the optic chiasm and optic nerve. Histopathological examination of the lesion showed cells arrangement in lobules separated by fibrous septae. Immunohistochemical staining of the cells was positive for CK, EMA, and S100 protein with a low proliferation index, consistent with chondroblastic chordoma. Three weeks after surgery, her visual acuity improved markedly to 20/20 in both eyes and her color vision was full in both eyes with the resolution of the left relative afferent pupillary defect. Follow-up 3 months later showed improvement of her left visual field defect. Optical coherence tomography showed preservation of the normal RNFL thickness in both eyes (See Supplemental Digital Content, Figure 1, http://links.lww.com/WNO/A674). The patient was scheduled to receive stereotactic radiosurgery for the residual tumor. Chordoma is a rare midline tumor that originates from the embryogenic notochord. The most common neuroophthalmic manifestations include headache and diplopia resulting from the sixth nerve palsy. Volpe et al reported 25 patients with chordoma and 4 of whom had chronic progressive visual loss due to compressive optic neuropathy. In 2 patients, vision loss was accompanied by the sixth nerve palsy (1). Atypical presentation of precipitous rapid vision loss simulating optic neuritis is rare and has been reported in other sellar tumors and pituitary masses (2). Our patient had acute deterioration of vision over a few days associated with ocular pain with eye movement, which led to the initial clinical diagnosis of optic neuritis. Chordomas grow slowly, and their symptoms tend to develop insidiously. The reported mean duration between the onset of symptoms and tumor diagnosis is variable between 16 and 41 months (3). Intermittent cranial nerve dysfunction has been reported in chordoma. The proposed e219 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Clinical Correspondence FIG. 1. MRI of the brain with contrast. (A) Sagittal T2 midline central skull base (3.2 · 3.2 · 4.5 cm) high-intensity signal mass with multiple punctate foci. (B) Coronal T2 section at the level of sella turcica showing skull-base chordoma (C) Sagittal T1 midline low signal intensity mass compressing the pituitary gland and optic chiasm (D) Coronal reformation T1 view of the mass and optic chiasm. mechanism is compression leading in the early stage to dislocation of the nodes of Ranvier and in the later stages into invagination of one paranoid into the adjacent one, thereby suppressing saltatory conduction (4). Temporary demyelination due to the compression of the optic nerve or chiasm in the patient has also been proposed to explain the clinical presentation simulating acute optic neuritis (5). Although ischemic mechanisms because of compression and vascular interruption have been proposed, the almost complete vision recovery would argue against this (2). In this patient, surgical decompression and debulking of the tumor resulted in good visual recovery. Moreover, the recovery of visual field defect and the preservation of the retinal fiber layer thickness by OCT suggest that the optic neuropathy was recent and rules out chronic compression. Clinicians need to be aware of the atypical presentation of acute rapid vision loss in patients with skull base and sellar chordomas. Prompt neuroimaging is critical even in “typical optic neuritis” to rule out mimickers such as compressive lesions of the optic nerve and chiasm. e220 STATEMENT OF AUTHORSHIP Conception and design: R. Behbehani; Acquisition of data: R. Behbehani; Analysis and interpretation of data: R. Behbehani, F. Dashti; Drafting the manuscript: R. Behbehani, F. Dashti; Revising the manuscript for intellectual content: R. Behbehani, F. Dashti; Final approval of the completed manuscript: R. Behbehani, F. Dashti. REFERENCES 1. Volpe NJ, Liebsch NJ, Munzenrider JE, Lessell S. Neuroophthalmologic findings in chordoma and chondrosarcoma of the skull base. Am J Ophthalmol. 1993;115:97–104. 2. Wu JK, Hedges TR III, Anderson ML, Folkerth RD. Surgical reversal of a subacute complete unilateral visual loss from an ovarian metastasis to the pituitary gland. Neurosurgery. 1992;31:349–352. 3. Rich TA, Schiller A, Suit HD, Mankin HJ. Clinical and pathologic review of 48 cases of chordoma. Cancer. 1985;56:182–187. 4. Ochoa J, Danta G, Fowler TJ, Gilliatt RW. Nature of the nerve lesion caused by a pneumatic tourniquet. Nature. 1971;233:265–266. 5. Clifford-Jones RE, Landon DN, McDonald WI. Remyelination during optic nerve compression. Trans Ophthalmol Soc U K. 1980;100:274–275. Ali et al: J Neuro-Ophthalmol 2023; 43: e219-e220 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.