Clinico-Radiological Spectrum and Management of Orbital Schwannomas: A Tertiary Care Institute Study

Orbital schwannoma arising within inferior rectus muscle: A rare orbital tumor

Purpose

To report a rare orbital schwannoma arising within inferior rectus muscle in a young woman.

Observations

In this case report, we describe a young patient with slowly progressive proptosis for one year. Preoperative imaging was suggestive of a benign tumor arising within inferior rectus muscle, and histopathologic evaluation revealed an orbital schwannoma with cystic degeneration.

Conclusion and importance

This case report highlights the importance of including schwannoma in the differential diagnosis of any orbital tumor arising within muscle.

Orbital Tumors-Clinical, Radiologic and Histopathologic Correlation

Orbital masses include a broad spectrum of benign and malignant entities. Often these masses are asymptomatic or show a slow growth rate, so that emergence of clinical symptoms is prolonged. In this context, cross-sectional imaging plays an elementary role in the characterization of these lesions. Aside from the characterization of the underlying entity, an evaluation of the involved compartments is possible by sufficient imaging, which also facilitates optimal treatment and surgery planning. The purpose of this review is to explore different benign and malignant orbital tumors and their typical appearance in imaging together with histopathologic findings.

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.

Atypical, Extremely Rapid Growth of Pediatric Orbital Neurilemmoma

Solitary orbital neurilemmoma-a benign tumor of Schwann cells in a peripheral nerve-sheath-are typically very slow growing and present in middle age; in the absence of neurofibromatosis, they are almost never seen in childhood. We describe the clinical presentation, imaging, pathology, and management of this tumor in a 12 years old-the tumor growing extremely rapidly over 5 months and without any evidence of cystic degeneration, hemorrhage, or sarcomatous features. The possibility of tumor growth having been accelerated by prior biopsy is discussed.

Orbital Schwannoma

Orbital schwannomas are rare neoplasms of the orbit. The presenting symptoms are often nonspecific. Classic imaging characteristics seen on magnetic resonance imaging (MRI) and orbital ultrasound can be useful to help aid in the diagnosis of orbital schwannoma. When diagnosed, the goal of treatment is complete surgical excision. The location of the tumor within the orbit dictates which surgical approach would provide the best exposure. When complete excision is achieved, recurrence rates are very low. This article addresses the etiology, patient population, presentation, natural history, and differential diagnosis of orbital schwannomas. Imaging characteristics and histopathologic subtypes are reviewed. Treatment goals, approaches, and specialties involved in the management of these patients is discussed. Finally, a representative case is presented.

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.