TNOA Journal of Ophthalmic Science and Research

CASE REPORT
Year
: 2021  |  Volume : 59  |  Issue : 3  |  Page : 289--291

A mysterious case of transient proptosis


Debolina Deb, Chaitanya Aravind Ankem, Suhas Prabhakar, M Radhakrishnan 
 Department of Ophthalmology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. Debolina Deb
Sri Ramachnadra Institute of Higher Education and Research, Porur, Chennai - 600 116, Tamil Nadu
India

Abstract

A 42-year-old Indian woman presented with a slowly progressive and painless swelling in the superomedial aspect of right orbit over past 5 years. She succumbed to homeopathic treatment which controlled the swelling for some time, but eventually recurred. The swelling led to protrusion of her right eye down and out. The patient's vision in her right eye was reduced, with restricted movement on elevation and adduction. The right eye pupil was sluggishly reacting to light. The fundus examination of the right eye revealed hyperemic disc with disc edema and retinal folds. Whereas, left ocular examination was normal. The computed tomography and magnetic resonance imaging scans of the right orbit revealed an intraconal, multiloculated lesion in the superomedial aspect of the orbit, adhering to the optic nerve, giving us an array of differential diagnosis. She underwent right anterolateral orbitotomy under general anesthesia; the masses excised were sent for histopathological examination, which gave the definitive diagnosis of a schwannoma.



How to cite this article:
Deb D, Ankem CA, Prabhakar S, Radhakrishnan M. A mysterious case of transient proptosis.TNOA J Ophthalmic Sci Res 2021;59:289-291


How to cite this URL:
Deb D, Ankem CA, Prabhakar S, Radhakrishnan M. A mysterious case of transient proptosis. TNOA J Ophthalmic Sci Res [serial online] 2021 [cited 2022 Nov 29 ];59:289-291
Available from: https://www.tnoajosr.com/text.asp?2021/59/3/289/325725


Full Text



 Introduction



Rare orbital tumors like schwannomas account for only 1%–6% of all orbital tumors.[1] Schwannomas are benign tumors that arise from the Schwann cells of the peripheral nerve, most commonly occurring in the head and neck region.[2] This tumor is usually solitary, slowly growing, well defined, and asymptomatic. The patient may become symptomatic as the tumor increases in size. This tumor has no gender or age predilection. Schwannoma in the eye may be seen in the orbit (1%–2% of all orbital tumors), conjunctiva,[2] eyelid,[3] or uveal tract.[4] The orbital schwannomas may arise from supraorbital, infraorbital, ciliary, supratrochlear, oculomotor, abducens, or trochlear nerves.[5]

 Case Report



A 42-year-old Indian woman presented with a painless, slowly growing mass in the superomedial aspect of the right orbit for the past 5 years. She has no systemic illness or previous history of seizures. She visited multiple doctors, without a conclusive diagnosis and treatment. The swelling subsided with homeopathic treatment, but reappeared 15 days back. The patient was initially treated conservatively as pseudotumor.

Three years back, contrast enhanced computed tomography (CT) scan of right orbit revealed right intraorbital lesion [Figure 1]. Magnetic resonance imaging (MRI) orbit revealed a lobulated intraconal lesion in superomedial aspect of the right orbit, adherent to the optic nerve, suspecting cavernous hemangioma or space-occupying lesion.{Figure 1}

On clinical examination, her right eye distant and color vision was reduced. She had eccentric proptosis of 25 mm with vertical and horizontal dystopia [Figure 2]; positive retropulsion with restricted elevation and adduction of the right eye [Figure 3]. The solid mass was well defined, nontender, extending behind the right orbit. The mass measured approximately 45 mm × 26 mm. The swelling did not vary in size with Valsalva maneuver or posture. The mass was nonpulsatile And had negative transillumination through it. Corneal and infraorbital sensations were intact. Supraorbital sensation was slightly reduced. Her right eye pupil was sluggishly reacting to light. Other neurological examination was normal. Intraocular pressure of both eyes was normal. On dilated fundus examination, the right eye revealed hyperemic disc with disc edema and retinal folds. Left eye anterior segment and fundus examination was normal.{Figure 2}{Figure 3}

Her blood investigations, including thyroid profile, were normal. Repeat CT brain revealed a large heterogeneous lobulated cystic lesion in the superomedial aspect of the right orbit, displacing superior rectus laterally and medial rectus inferiorly, and no lesions in the brain. MRI orbit revealed a right, intraconal, multiloculated lesion, adherent to optic nerve [Figure 4].{Figure 4}

The patient underwent right transseptal anteromedial orbitotomy under general anesthesia, and mass was removed en bloc. Intraoperatively, two encapsulated masses were excised and sent for histopathological examination. On gross examination, the specimens were seen as grayish white solid masses. Microscopically, the tumor cells were seen in a biphasic pattern with benign spindle cells having fusiform nuclei and eosinophilic cytoplasm, along with myxoid tissue and ovoid cells. These cells were arranged in a palisading pattern representing classic Verocay bodies [Figure 5]. There was no evidence of any malignant transformation. The final diagnosis of Benign schwannoma of the right orbit was thus made. Her postoperative recovery was uneventful [Figure 6].{Figure 5}{Figure 6}

 Discussion



Orbital tumors of neurogenic origin are a rare finding. Among all orbital tumors, orbital schwannomas account for 1%–6% of cases.[1] Schwannoma was defined first by Verocay in 1908 as benign tumors arising from the Schwann cells of peripheral nerves.[6] Orbital schwannomas may arise from one of the sensory or cranial nerves traversing the orbit such as supraorbital, supratrochlear, infraorbital, ciliary, oculomotor, abducens, or trochlear nerve. It is commonly encountered between the second to fourth decades of life, which gradually evolves in size over months to years.[7]

Orbital schwannoma is a slowly progressive tumor with variable presentation and location. These benign tumors are asymptomatic when they are small in size but become symptomatic as their size increases in size, as seen in our patient. It generally does not affect extraocular movements unless the tumor is large enough to compress the optic nerve or is located at the orbital apex.[8] The tumor in our patient increased slowly posteriorly, thereby causing eccentric proptosis of the right eye. Clinically on palpation, it is seen as a solitary, soft, well-defined mass.[9] As the size of the tumor increased, it displaced the superior rectus and medial rectus and also compressed the optic nerve. Thus, the patient had mechanical restriction of elevation and adduction of her right eye. As the optic nerve was compressed, her vision dropped, pupil reaction was sluggish, and features of disc edema were seen in the right eye.

We can draw a list of differential diagnosis for slow-growing painless orbital mass such as meningioma, cavernous hemangioma, hemangiopericytoma, or optic nerve gliomas. On CT Orbit, schwannoma is seen as a poorly enhancing extraconal mass, which may be confused with epidermoid cyst, hemangioma, inflammatory pseudotumor, lymphoma, fibrous histiocytomas, leiomyoma, meningioma, solitary fibrous tumor, and hemangiopericytomas. Whereas, MRI with contrast enhancement is a better radiological tool to determine orbital schwannoma. These tumors are seen as low-intensity signals on T1 weighted MRI and high-density signals on T2 weighted MRI. On contrast, these tumors have homogenous or heterogeneous enhancement, which helps us to differentiate it from hemangioma.[10] Contrary to the radiological findings in other studies, our patient's orbital CT scan showed intraconal mass and MRI orbit showed intraconal homogenously enhanced lesions. The definitive diagnosis of schwannoma can only be confirmed by histopathological examination of the excised mass.

The definitive treatment for such tumors is surgical excision with intact capsule. The location of lesion as seen in CT and MRI scans determines the surgical approach such as anterior, lateral, frontal, or combined orbitotomy. As our patient had the tumor arising from the superomedial aspect of the right orbit, We approached the tumour from antero-lateral aspect of the orbit.

Orbital Schwannomas are a diagnostic challenge for ophthalmologists due to their rarity and variable presentations and locations. It is difficult to locate the origin of orbital tumors owing to the complexity of orbital structures. As it is difficult to rule out other differential diagnoses of a slow-growing, painless orbital mass by noninvasive investigations, surgical excision and histopathological examination is warranted as definitive management for these tumors.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Acknowledgment

We would like to acknowledge the Department of Pathology, SRIHER, for the gross and microscopic examination of the specimens. We would also like to acknowledge Dr. Aravind Babu for helping with the follow-up of the patient.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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