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Show PHOTO ESSAY Neurosarcoidosis Mimicking a Malignant Optic Glioma Jeffrey M. Pollock, MD, Francis G. Greiner, MD, Jason B. Crowder, MD, Jessica W. Crowder, MD, and Eugene Quindlen, MD Abstract: A 55-year-old African-American man de-veloped progressive unilateral optic neuropathy and periocular pain. MRI showed thickening and enhance-ment of the mid-orbital segment of the ipsilateral optic nerve. Optic neuritis was diagnosed, and he was treated with corticosteroids without improvement. After being lost to follow-up, he returned with wors-ening vision in the affected eye, aggravated pain, and proptosis. MRI now showed thickening and enhance-ment of the entire orbital and intracranial segments of the optic nerve. Because the patient had no light per-ception vision in that eye and a malignant glioma was suspected, he underwent optic nerve biopsy that revealed non-caseating granulomas throughout the optic nerve tissue. CT body imaging failed to disclose other evidence of sarcoidosis. Neurosarcoidosis lim-ited to the optic nerve is rare but should always be suspected in such circumstances. An exhaustive effort to find extracranial evidence for this diagnosis should be undertaken before resorting to optic nerve biopsy. (J Neuro-Ophthalmol 2008;28:214-216) A 25-year-old African-American man presented to the neurology clinic with progressive left eye vision loss, proptosis, and periocular pain. ‘‘Atypical optic neuritis'' had been diagnosed 9 months previously. MRI at that time had shown enhance-ment in the mid-portion of the left optic nerve (Fig. 1A). He had been treated with 1 g of intravenous prednisolone for 4 days, followed by oral prednisone in a tapering dose for 14 days with slight symptomatic improvement. Against medical advice, the patient did not return to the clinic for follow-up examinations. The patient finally returned 9 months later because left eye visual loss had recurred, together with left periocular pain and proptosis progressing over several months. The patient had no light perception in the left eye. The left globe was mildly proptotic (3 mm) without lid retraction and was deviated laterally. There was a left afferent pupillary defect. Ophthalmoscopy revealed mild left optic nerve pallor. Results of the remainder of the ophthalmic examination were unremarkable. MRI now showed diffuse enlargement and enhance-ment of the left optic nerve extending from the globe to the optic chiasm (Fig. 1B). Coronal sections revealed that the signal abnormalities affected the meninges and parenchyma of the optic nerve (Fig. 2). The patient had a radiograph of the chest and CT of the chest, abdomen, and pelvis, which showed no radio-graphic manifestations of sarcoidosis. Because of concern for a neoplastic process such as a malignant glioma, the left FIG. 1. A. Postcontrast T1 axial MRI performed at our first encounter with the patient shows mid-orbital thickening and enhancement of the left optic nerve. B. Postcontrast T1 axial MRI performed 9 months after our first encounter with the patient now shows that the thickening and enhancement of the left optic nerve extends from the globe to the chiasm. Department of Neuroradiology (JMP), Wake Forest University, Winston-Salem, North Carolina; and Departments of Neuroradiology (FGG, JBC), Neurology (JWC), and Neurosurgery (EQ), University of South Alabama, Mobile, Alabama. Address correspondence to Jeffrey M. Pollock, MD, Wake Forest University School of Medicine, Radiology Department, Medical Center Boulevard, Winston-Salem, NC 27157; E-mail:jeffmpollock@gmail.com 214 J Neuro-Ophthalmol, Vol. 28, No. 3, 2008 optic nerve was biopsied. At the time of biopsy, the visual appearance and frozen section suggested glioma. But the final histologic examination revealed non-caseating gran-ulomas with giant cells completely replacing the meninges and normal architecture of the nerve, a pattern consistent with sarcoidosis. The patient was treated with cortico-steroids without improvement in his vision. Sarcoidosis involves the meninges, brain, spinal cord, or nerves (neurosarcoidosis) in fewer than 5% of patients (1). Neurosarcoidosis most commonly presents with cranial nerve palsies, usually those of the facial and optic nerves (2). Optic nerve sarcoidosis may present as isolated involv-ement of the nerve, optic chiasm, or optic nerve sheath. Most cases show mixed involvement (3). Tabulation of case reports and case series yielded 134 patients with in-tracranial sarcoidosis confirmed by MRI or CT. Lesions were seen in the optic nerve in 26.8% (n = 36), in the optic chiasm in 16.4% (n = 22), and in the optic nerve sheath in 5.8% (n = 8) of patients (3-16). Lesions of the nerve sheath have a better prognosis and can mimic a meningioma, idiopathic orbital inflammation (orbital pseudotumor), or leptomeningeal spread of tumor, whereas lesions of the optic nerve can mimic optic neuritis or an optic glioma (9). Regardless of location in relation to the optic nerve, sar-coidosis in these reports presented with progressive vision loss (3). A patient presenting with isolated optic nerve sar-coidosis without additional lesions is very unusual (3,17). Over the last 40 years, 20 patients with isolated biopsy-proven optic nerve sarcoidosis have been described (7,9, 11). The majority of these reports predated the availability of MRI. Preoperative suspicion of an optic nerve menin-gioma or glioma was based on optic canal enlargement on plain radiography (11). How many of these patients may have had additional intracranial lesions is not known. Most low-grade optic gliomas present in children. The differential diagnosis for optic nerve enhancement in the adult includes optic neuritis, sarcoidosis, and optic glioma (18). The adult form of optic nerve glioma is highly aggressive, very rare, and usually fatal within 1 year (19). Several authors have advocated a trial of corticosteroids before biopsy of the optic nerve, given that most menin-giomas or gliomas will not show clinical or radiologic improvement, whereas neurosarcoidosis typically will show improvement (3). An adult patient presenting with optic pathway symp-toms, isolated optic nerve enhancement, and features atypical for demyelinating optic neuritis will be a diagnostic challenge that can be frequently resolved by short-term follow-up examinations and a careful clinical history. Sarcoidosis should be remembered because of its ability to mimic multiple imaging findings. A systemic imaging eval-uation for characteristic lesions or a successful trial of cor-ticosteroids may suggest this diagnosis and obviate the need for optic nerve biopsy. REFERENCES 1. Johns CJ, Michele TM. The clinical management of sarcoidosis. A 50-year experience at the Johns Hopkins Hospital. Medicine (Baltimore) 1999; 78:65-111. 2. Dubois PJ, Beardsley T, Klintworth G, et al. Computed tomog-raphy of sarcoidosis of the optic nerve. Neuroradiology 1983;24: 179-82. 3. Carmody RF, Mafee MF, Goodwin JA, et al. Orbital and optic pathway sarcoidosis: MR findings. AJNR Am J Neuroradiol 1994;15: 775-83. 4. Segal EI, Tang RA, Lee AG, et al. Orbital apex lesion as the presenting manifestation of sarcoidosis. J Neuroophthalmol 2000;20: 156-8. 5. Beardsley TL, Brown SV, Sydnor CF, et al. Eleven cases of sarcoidosis of the optic nerve. Am J Ophthalmol 1984;97:62-77. 6. Engelken JD, Yuh WT, Carter KD, et al. Optic nerve sarcoidosis: MR findings. AJNR Am J Neuroradiol 1992;13:228-30. 7. Jennings JW, Rojiani AM, Brem SS, et al. Necrotizing neuro-sarcoidosis masquerading as a left optic nerve meningioma: case report. AJNR Am J Neuroradiol 2002;23:660-2. 8. Lexa FJ, Grossman RI. MR of sarcoidosis in the head and spine: spectrum of manifestations and radiographic response to steroid therapy. AJNR Am J Neuroradiol 1994;15:973-82. 9. Ng KL, McDermott N, Romanowski CA, et al. Neurosarcoidosis masquerading as glioma of the optic chiasm in a child. Postgrad Med J 1995;71:265-8. 10. Zajicek JP, Scolding NJ, Foster O, et al. Central nervous system sarcoidosis-diagnosis and management. Q J Med 1999;92:103-17. 11. Ing EB, Garrity JA, Cross SA, et al. Sarcoid masquerading as optic nerve sheath meningioma. Mayo Clin Proc 1997;72:38-43. FIG. 2. Postcontrast T1 coronal MRI performed at our first encounter with the patient shows that the thickening and enhancement affect the meninges and parenchyma of the left optic nerve. A. Anterior orbit. B. Mid-orbit. C. Posterior orbit. D. Optic nerve-chiasm junction. 215 Neurosarcoidosis J Neuro-Ophthalmol, Vol. 28, No. 3, 2008 12. Roberti F, Lee HH, Caputy AJ, et al. ‘‘Shave'' biopsy of the optic nerve in isolated neurosarcoidosis. J Neurosurg Sci 2005;49:59-63. 13. Lamirel C, Badelon I, Gout O, et al. Neuro-ophthalmologic initial presentation of sarcoidosis (in French). J Fr Ophtalmol 2006;29:241-9. 14. Frohman LP, Guirgis M, Turbin RE, et al. Sarcoidosis of the anterior visual pathway: 24 new cases. J Neuroophthalmol 2003;23:190-7. 15. Cooper SD, Brady MB, Williams JP, et al. Neurosarcoidosis: evaluation using computed tomography and magnetic resonance imaging. J Comput Tomogr 1988;12:96-9. 16. Castagna I, Salmeri G, Fama F, et al. Optic nerve granuloma as first sign of systemic sarcoidosis. Ophthalmologica 1994;208:230-2. 17. Jordan DR, Anderson RL, Nerad JA, et al. Optic nerve involvement as the initial manifestation of sarcoidosis. Can J Ophthalmol 1988; 23:232-7. 18. Lury KM, Smith JK, Matheus MG, et al. Neurosarcoidosis-review of imaging findings. Semin Roentgenol 2004;39:495-504. 19. Millar WS, Tartaglino LM, Sergott RC, et al. MR of malignant optic glioma of adulthood. AJNR Am J Neuroradiol 1995;16:1673-6. 216 q 2008 Lippincott Williams & Wilkins J Neuro-Ophthalmol, Vol. 28, No. 3, 2008 Pollock et al |
