Inferior oblique schwannoma: diagnosis and management

Orbital Schwannoma With Frontal Bone Lysis

Orbital schwannoma is an exceptionally rare cause of ptosis. Diagnosis may be elusive given its slow rate of growth and its various presentations depending on localization. Herein, we report the case of a 50-year-old male who presented to our clinic with a complaint of unilateral, recurrent ptosis of the left eye. He underwent levator palpebrae resection, which was unsuccessful at improving his ptosis. He later represented with acute-onset diplopia for which magnetic resonance imaging was obtained. Magnetic resonance imaging showed a lesion in the superior orbit with secondary bony dehiscence of the orbital roof. Through a vertical lid-split incision, the lesion was removed, and the frontal lobe was observed protruding through the defect in the orbital roof. This case highlights the importance of diagnostic skepticism in the face of recurrent ptosis and emphasizes the utility of the vertical lid-split approach for anterior lesions of the superior orbit.

Orbital schwannoma management: a case report, literature review, and potential paradigm shift

PURPOSE

To present a case of orbital schwannoma and assess the literature on treatment modalities.

METHODS

A MEDLINE literature search for cases of orbital schwannomas was performed using the PubMed search tool using the search terms "orbital schwannoma" and "orbital neurilemmoma." Papers were included if they were peer-reviewed, published in English, discussed management, and included the search terms. Each article was rated using the scale developed by the British Centre for Evidence-Based Medicine. In addition, we present a case report of an orbital schwannoma.

RESULTS

A total of 428 articles were found. 102 met the criteria for inclusion. Only two articles met Level 1 evidence and 16 were important to the clinical care process. We report a case of a biopsy-proven orbital schwannoma managed conservatively with observation over a 4-year period due to risk of cosmetic disfigurement with tumor removal. There has been no change in tumor size and no associated complications during follow up.

CONCLUSIONS

There is a paucity of data on the natural history of orbital schwannomas. Based on our review of the literature, we recommend observation for asymptomatic or minimally symptomatic orbital schwannomas with minimal growth over an extended period of time. For rapidly growing tumors or large tumors affecting key structures causing visual loss, diplopia, aesthetic disfigurement, or patient discomfort, a more aggressive approach may be necessary.

Orbital Schwannoma With Atypical Presentation

Orbital schwannomas are characteristically slow-growing benign tumors arising from peripheral sensory nerves. However, the authors' case illustrates the atypical presentation of such a tumor.A 71-year-old male presented with proptosis, visual loss, and periorbital inflammation. Sequential imaging showed continuous and rapid growth of an intraconal mass arising from the medial rectus. Excision of the mass was performed and it was histopathologically proven to be an orbital schwannoma.This patient demonstrates the atypical presentation of an orbital schwannoma, arising from an extraocular muscle with rapid progressive growth and inflammation, indicating it should be considered a differential diagnosis in orbital masses presenting as such.