Isolated Intraconal Meningioma
Purpose: To report a rare case of isolated intraconal meningioma.
Case Report: A 24-year-old woman presented with painless proptosis in her left eye which started and progressed during her pregnancy about 10 months ago. Hertel exophthalomometry revealed anterior displacement of the globe with 4 mm of proptosis which was remarkable. Magnetic resonance imaging (MRI) demonstrated an intraconal circumscribed oval-shaped mass with hypointense signals on T1- weighted images and hyperintense signals on T2-weighted images, mimicking cavernous hemangioma. This mass, however, was free of any connections to optic nerve or bones. Due to the imaging characteristics, more prevalent diagnoses like cavernous hemangioma were placed on the top of the differential diagnoses list. However, during the surgical excision, the tumor’s consistency and gross features were not compatible with cavernous hemangioma. The pathologic findings instead determined meningotheliomatous meningioma, a very rare condition, which was far from our expectations prior to the surgery.
Conclusion: Ectopic orbital meningiomas are rare tumors that are not easily diagnosed without postoperative histopathology. Despite its low prevalence, they should be considered in the differential diagnosis list of intraconal masses with hypointense signals on T1-weighted images and hyperintense signals on T2- weighted images.
Ectopic Meningioma, Intraconal Meningioma, Orbital Meningioma, Primary Meningioma
1. Bondy M, Ligon BL. Epidemiology and etiology of intracranial meningiomas: a review. J Neurooncol 1996;29:197–205.
2. Lang FF, Macdonald OK, Fuller GN, DeMonte F. Primary extradural meningiomas: a report on nine cases and review of the CT-era literature. J Neurosurg 2000;93:940– 950.
3. Decock CE, Kataria S, Breusegem CM, Van Den Broecke CM, Claerhout IJ. Ectopic meningioma anterior to the lacrimal gland fossa. Ophthalmic Plast Reconstr Surg 2009;25:57–59.
4. Arai KS, T. Matsumoto, H. Free-lying ectopic meningioma within the orbit. Br J Neurosurg 1997;11:560–563.
5. Farah SE, Konrad H, Huang DT, Geist CE. Ectopic orbital meningioma: a case report and review. Ophthalmic Plast Reconstr Surg 1999;15:463–466.
6. Johnson TE, Weatherhead RG, Nasr AM, Siqueira EB. Ectopic (extradural) meningioma of the orbit: a report of two cases in children. J Pediatr Ophthalmol Strabismus 1993;30:43–47.
7. Pushker N, Shrey D, Kashyap S, Sen S, Khurana S, Sharma S. Ectopic meningioma of the orbit. Int Ophthalmol 2013;33:707–710.
8. Tan K, Lim A. Primary extradural intra-orbital meningioma in a Chinese girl. Br J Ophthalmol 1965;49:377.
9. Yokoyama T, Nishizawa S, Sugiyama K, Yokota N, Ohta S, Uemura K, et al. Primary intraorbital ectopic meningioma. Skull Base Surg 1999;9:47–50.
10. Gündüz K, Kurt RA, Erden E. Ectopic orbital meningioma: report of two cases and literature review. Surv Ophthalmol 2014;59:643–648.
11. Tendler I, Belinsky I, Abramson DH, Marr BP. Primary extradural ectopic orbital meningioma. Ophthalmic Plast Reconstr Surg 2017;33:S99–S101.
12. Tan LT, Stewart CM, Sheerin F, MacDonald B, Silva P, Norris JH. Ectopic orbital meningioma: Fact or fiction? Orbit 2017;36:144–146.
13. Huang X, Tang D, Wu T, Jian T, Sun F. Ectopic orbital meningioma: a retrospective case series. BMC Ophthalmol 2018;18:296.