An Eyelid Mass Revealing an Intraorbital Schwannoma: A Rare Case Report
ASMAE NAJAH *
Department of Ophthalmology, Arrazi Hospital, Mohammed VI University Hospital Center, Marrakech, Morocco.
SARAH BELGHMAIDI
Department of Ophthalmology, Arrazi Hospital, Mohammed VI University Hospital Center, Marrakech, Morocco.
HIND SAFI
Department of Ophthalmology, Arrazi Hospital, Mohammed VI University Hospital Center, Marrakech, Morocco.
YOUNES TLEMCANI
Department of Ophthalmology, Arrazi Hospital, Mohammed VI University Hospital Center, Marrakech, Morocco.
ABDELJALIL MOUTAOUAKIL
Department of Ophthalmology, Arrazi Hospital, Mohammed VI University Hospital Center, Marrakech, Morocco.
ZAKARIA AZIZ
Department of Maxillo-facial and Aesthetic Surgery, Ibn Tofail Hospital, Mohammed VI University Hospital Center, Marrakech, Morocco.
INTISSAR SALHI
Department of Maxillo-facial and Aesthetic Surgery, Ibn Tofail Hospital, Mohammed VI University Hospital Center, Marrakech, Morocco.
GASTLI SKANDER
Department of Maxillo-facial and Aesthetic Surgery, Ibn Tofail Hospital, Mohammed VI University Hospital Center, Marrakech, Morocco.
NADIA MANSOURI
Department of Maxillo-facial and Aesthetic Surgery, Ibn Tofail Hospital, Mohammed VI University Hospital Center, Marrakech, Morocco.
MARIA DREF
Department of Pathology, Arrazi Hospital, Mohammed VI University Hospital Center, Marrakech, Morphoscience Research Laboratory, Morocco.
HIND RACHADI
Department of Pathology, Arrazi Hospital, Mohammed VI University Hospital Center, Marrakech, Morphoscience Research Laboratory, Morocco.
HANANE RAIS
Department of Pathology, Arrazi Hospital, Mohammed VI University Hospital Center, Marrakech, Morphoscience Research Laboratory, Morocco.
*Author to whom correspondence should be addressed.
Abstract
Introduction: Orbital schwannomas are rare benign tumors arising from Schwann cells of peripheral nerve sheaths and account for a small percentage of orbital masses. They are most commonly located within the intraconal space, while involvement of extraocular muscles is exceptional. We report a rare case of an isolated schwannoma originating from the inferior rectus muscle.
Case Presentation: A 60-year-old woman with no significant medical history presented with a progressive left lower eyelid swelling evolving over three months, associated with binocular vertical diplopia. Ophthalmological examination revealed normal best-corrected visual acuity in both eyes, left hypertropia, a well-circumscribed inferior eyelid mass, and limitation of downgaze. Orbital magnetic resonance imaging demonstrated a well-defined lesion arising from the left inferior rectus muscle, measuring 21 × 13.5 × 12 mm, hypointense on T1-weighted images, hyperintense on T2-weighted images, with peripheral gadolinium enhancement. The lesion displaced the globe superiorly without intraocular extension. Histopathological examination following transconjunctival biopsy confirmed the diagnosis of schwannoma. Complete en bloc surgical excision was achieved via a subciliary approach. The postoperative course was uneventful, and no recurrence was observed after one year of follow-up.
Discussion: Orbital schwannomas represent approximately 1–6.5% of orbital tumors and typically present with slowly progressive symptoms related to mass effect. Imaging, particularly MRI, plays a crucial role in lesion characterization and surgical planning, while histopathological analysis remains essential for definitive diagnosis. Complete surgical excision is the treatment of choice and is associated with excellent outcomes and a low recurrence rate.
Conclusion: Although rare, intraorbital schwannoma should be considered in the differential diagnosis of atypical orbital masses presenting with diplopia. MRI findings are suggestive, but histological confirmation is necessary. Early and complete surgical excision offers a favorable prognosis.
Keywords: Schwannoma, muscle, orbital masses, exophthalmos