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Ectopic intraconal orbital meningioma – A rare case report
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How to cite this article: Sharma AK, Gandhoke CS, Misra S, Ravi A, Gupta RK, Gupta SK. Ectopic intraconal orbital meningioma – A rare case report. Surg Neurol Int 2020;12:305.
Abstract
Background:
Ectopic orbital meningiomas (OM) are a rare subset of OMs which are neither attached to the optic nerve sheath nor to the surrounding bone.
Case Description:
We report the case of a 65-year-old female who presented with a 1 year history of proptosis followed by visual loss and restricted right eye movements since 3 months. Radiology of the orbits was suggestive of intraorbital, intraconal, and heterogeneous contrast enhancing right eye lesion which was completely excised through supraorbital orbitotomy approach. Intraoperatively, the right optic nerve, though compressed, and displaced inferiorly, was free from the lesion. The final histopathological diagnosis was “Meningioma WHO Grade I.” At 3 months follow-up, patient’s vision in the right eye improved from perception of light positive to 6/12 and there was no evidence of recurrence.
Conclusion:
Rarity of ectopic OM, total surgical excision with an excellent postoperative visual outcome prompted us to report this case.
Keywords
Ectopic orbital meningioma
Intraconal
Optic nerve
Proptosis
Visual loss
INTRODUCTION
Orbital meningiomas (OMs) comprise 0.4–2% of all meningiomas.[1] Primary OM arises from the optic nerve sheath arachnoid cap cells and constitutes less than 1/3rd of all OMs.[3] Secondary OM is a direct extension of intracranial meningiomas into the orbit and constitutes approximately 2/3rd of all OMs.[3] A third rare subset of OM, “ectopic orbital meningioma” arises from ectopic rests of arachnoid cells and is attached neither to the optic nerve sheath nor to the surrounding bone (sphenoid wing, anterior clinoid, tuberculum sellae, etc.).[4]
CASE REPORT
We report the case of a 65-year-old female who presented with complaints of painless proptosis of the right eye since 1 year followed by gradual progressive visual loss and restricted right eye movements since 3 months [Figure 1]. There was no history of diplopia. The patient underwent a complete clinical, ocular, and radiological evaluation. Visual acuity of the right eye was found to be perception of light positive. Hertel’s exophthalmometer revealed a 3 mm proptosis of the right eye [Figure 1]. The pupillary reaction was ill sustained. Fundoscopy revealed right eye optic atrophy.

Computed tomography and magnetic resonance imaging (MRI) of the orbits (plain plus contrast) revealed an intra-orbital, intra-conal, and heterogeneous contrast enhancing mass in the right eye [Figure 2]. The lesion was causing displacement of the globe anteriorly and slightly inferiorly, resulting in proptosis [Figure 2]. The right optic nerve was displaced inferiorly. The left eye and orbit did not reveal any abnormality. Intracranial structures were normal and there was no intracranial extension of the lesion.

Patient underwent total excision of the mass through supraorbital orbitotomy approach, using supra-brow incision. This approach allows an excellent exposure and optimal surgical operability in the orbit with minimal manipulation of the orbital structures, is not limited by tumor size, and has an excellent cosmetic result. Lesion was approached by a simple skin incision of 4 cm along the orbital rim. After detachment of the periosteum, the supraorbital nerve was dissected free and the periorbita was separated from the inner orbital roof. A single key burr hole was placed in the temporal fossa, at the frontosphenoidal suture just behind the zygomatic process of the frontal bone. An osteotomy of the middle part of the supraorbital rim was performed using a reciprocating saw and a small frontobasal trephination was carried out respecting the lateral border of the frontal sinus. The basal dura of the frontal lobe was pushed away and the orbital roof was removed. The tumor was identified after opening the periorbita [Figure 3].

Intraoperatively, the lesion was firm in consistency, encapsulated, well-defined with distinct borders and was excised completely. The right optic nerve, though compressed and displaced inferiorly, was free from the lesion [Figure 3]. The mass was completely removed using standard microsurgical techniques and sent for histopathological evaluation. Mini plates were used on both sides of the orbital rim for orbital reconstruction.
Microscopic examination of hematoxylin and eosin slides showed a tumor which was comprised of meningothelial cells arranged in microcystic pattern with cob-web like background admixed with variable sized dilated vascular channels and focal lympho-plasmacytic cell aggregates. The meningothelial cells showed slender elongated nuclei with degenerative changes. The final histopathological diagnosis was “Meningioma-mixed microcystic angiomatous pattern, WHO Grade I” [Figure 4].

In the immediate postoperative period, patient’s proptosis and vision improved (finger counting at 2 feet) [Figure 1]. At 3 months follow-up, patient’s vision in the right eye was 6/12 and there was no clinical or radiological evidence of recurrence [Figure 5].

DISCUSSION
Ectopic OM is a rare entity. The etiopathogenesis of ectopic OM is not fully understood. The possible hypothesis include congenitally dislocated arachnoid nests within the periorbita or regressed orbital meningoceles which undergo tumor transformation or the presence of tumors originally in the optic nerve sheath that become detached and migrate to an ectopic location.[2,11] Ectopic OM may be associated with penetrating trauma to the orbit, which serves to dislodge the meningeal tissues within the orbit that later act as a nidus for the development of meningiomas.[4,8] In our case, history of orbital trauma was not present.
Ectopic OM occurs more commonly in the younger age groups and predominates in the medial orbit.[5] Ectopic OM differ from optic nerve sheath meningiomas in having late visual affection as compared to optic nerve sheath meningiomas in which visual loss is a predominant and early symptom.[7,9] On MRI, ectopic OM usually appears as a well-defined, T1 hypointense and T2 hyperintense lesion with heterogeneous post contrast enhancement with or without extraocular muscular adhesions.[5] Ectopic OM may be associated with asymmetric development of the paranasal sinuses.[12] The most common histologic type of ectopic OM is the meningotheliomatous variety.[6,7] On immunohistochemistry, these tumors are positive for epithelial membrane antigen and vimentin.[7]
Treatment of choice for ectopic OM is complete surgical excision wherever feasible. Recurrence is rare after complete excision. Residual/recurrent tumors after subtotal resection can be offered a second surgery or radiotherapy. Gündüz et al. in their report of two cases of ectopic OMs gave adjuvant radiotherapy in both the cases after subtotal tumor resection.[5] One, out of the two patients, developed proliferative radiation retinopathy and vision loss.[5] Pushker et al. in their paper reported recurrence in two out of the three cases of ectopic OMs which were treated with repeat surgical excision with no further recurrence.[10] On the contrary, the literature advocates radiotherapy as the 1st line of treatment for optic nerve sheath meningiomas.[13]
CONCLUSION
Worldwide, only around 20 cases of ectopic OM have been reported.[7] Rarity of ectopic OM, total surgical excision with an excellent postoperative visual outcome prompted us to report this case.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
REFERENCES
- J Neurooncol. 1996;29:197-205.Epidemiology and etiology of intracranial meningiomas: A review.
- [Google Scholar]
- Ophthalmic Plast Reconstr Surg. 2009;25:57-9.Ectopic meningioma anterior to the lacrimal gland fossa.
- [Google Scholar]
- Surv Ophthalmol. 1992;37:167-83.Optic nerve sheath meningiomas.
- [Google Scholar]
- Ophthalmic Plast Reconstr Surg. 1999;15:463-6.Ectopic orbital meningioma: A case report and review.
- [Google Scholar]
- Surv Ophthalmol. 2014;59:643-8.Ectopic orbital meningioma: Report of two cases and literature review.
- [Google Scholar]
- Clin Rhinol An Int J. 2017;10:32-5.Ectopic inferior orbital meningioma.
- [Google Scholar]
- BMC Ophthalmol. 2018;18:296.Ectopic orbital meningioma: A retrospective case series.
- [Google Scholar]
- J Pediatr Ophthalmol Strabismus. 1993;30:43-7.Ectopic (extradural) meningioma of the orbit: A report of two cases in children.
- [Google Scholar]
- Br J Ophthalmol. 1969;53:169-73.Primary intraorbital meningioma.
- [Google Scholar]
- Int Ophthalmol. 2013;33:707-10.Ectopic meningioma of the orbit.
- [Google Scholar]
- Br J Ophthalmol. 1965;49:377-80.Primary extradural intra-orbital meningioma in a Chinese girl.
- [Google Scholar]
- Ophthal Plast Reconstr Surg. 2017;33:S99-101.Primary Extradural Ectopic Orbital Meningioma.
- [Google Scholar]
- Ophthalmology. 2002;109:890-900.A long-term visual outcome comparison in patients with optic nerve sheath meningioma managed with observation, surgery, radiotherapy, or surgery and radiotherapy.
- [Google Scholar]