Our patient was a 17-year-old female who presented with a one-month history of left lower eyelid swelling that was preceded by an upper respiratory infection. She had no underlying medical problems and no constitutional symptoms.

THE OCULAR EXAM

Our exam revealed the following:

• Distance VA without correction: 20/20-2 OD, 20/20-1 OS
• Pupils: reactive without afferent pupillary defect OU
• IOP: 21 mm Hg OD, 22 mm Hg OS with Tono-Pen
• External exam: left lower lid edema with distensible, cystic nontender lesions of the inferior and lateral orbit present on palpation that did not enlarge with Valsalva maneuver, with associated superonasal displacement of the left globe and 3-mm proptosis (Figure 1)



• Anterior and posterior segments: unremarkable

CT (scan) maxillofacial demonstrated a cystic bilobed lesion of the inferior and lateral left orbit (Figure 2, page 55).

A PRELIMINARY DIAGNOSIS

Given the patient’s age and history, she was initially thought to have an orbital lymphangioma. Orbital lymphangiomas are abnormal, low-flow vascular channels that form due to cellular signaling dysregulation, which leads to irregular proliferation of endothelial cells.^1,2 Orbital lymphangiomas usually are diagnosed before 16 years. Patients present with eyelid swelling, ptosis, proptosis, pain or eye motility restriction.³ Management consists of surgical resection or intralesional injection of a sclerosing agent such as sodium morrhuate 5% or doxycycline, which has been shown to decrease lesion size.^1,4 The patient was started on prednisone and referred to interventional radiology (IR) for sclerotherapy.

AN UNEXPECTED TURN

Care with IR began, but the patient experienced multiple failed attempts at percutaneous sclerotherapy. Our service then performed an orbitotomy with excisional biopsy, wherein intraoperative frozen tissue sections demonstrated small blue cells; final pathology read orbital embryonal rhabdomyosarcoma, with immunohistochemical studies demonstrating antibodies to the protein desmin.

Orbital rhabdomyosarcoma (RMS) is the most common mesenchymal tumor of childhood.⁵ While cases have been reported across age groups, orbital RMS typically presents in the first decade with rapidly worsening proptosis and/or globe displacement.^6,7 CT imaging of RMS often shows a well-delineated, homogenous mass external to the muscle cone, isodense to muscle tissue, and if diagnosed early in the disease course, usually without associated bony destruction.⁸

The three histological subtypes of RMS are pleomorphic, embryonal and alveolar. Embryonal is the most common, and alveolar has the worst, meaning life-threatening, prognosis.^9,10 Immunohistochemical studies are diagnostically valuable in RMS as antibodies to desmin and vimentin are sensitive markers of disease presence.¹¹ Treatment selection and regimen intensity are determined by postbiopsy staging. The earliest stage warrants chemotherapy only, and later stages require chemotherapy plus radiotherapy at progressively larger doses.¹²

After biopsy results were finalized, the patient was referred to an oncologist for systemic work-up and initiation of chemotherapy and radiation.

TAKE-HOME POINT

Rhabdomyosarcoma is one of the few life-threatening diagnoses that presents to ophthalmologists. This case demonstrates the importance of maintaining a high index of suspicion for this malignancy in a young patient with a new and rapidly growing orbital mass. OM

REFERENCES

1. Nassiri N, Rootman J, Rootman DB, Goldberg RA. Orbital lymphaticovenous malformations: Current and future treatments. Surv Ophthalmol. 2015 Sept-Oct;60:383-405.
2. Vikkula M, Boon LM, Mulliken JB, Olsen BR. Molecular basis of vascular anomalies. Trends Cardiovasc Med. 1998 Oct;8:281-292.
3. Greene AK, Burrows PE, Smith L, Muliken JB. Periorbital lymphatic malformation: clinical course and management in 42 patients. Plast Reconstr Surg. 2005 Jan;115:22-30.
4. Schwarcz RM, Simon GJ, Cook T, Goldberg RA. Sclerosing therapy as first line treatment for low flow vascular lesions of the orbit. Am J Ophthalmol. 2006 Feb;141:333-339.
5. Conneely MF, Mafee MF. Orbital rhabdomyosarcoma and simulating lesions. Neuroimaging Clin N Am. 2005 Feb;15:121-136.
6. Rootman J, editor. Neoplasia. Vol. 54. Lippincott Williams and Wilkins; Philadelphia: 2003. pp. 262-268. (Diseases of the orbit: a multidisciplinary approach).
7. Turner JH, Richmon JD. Head and neck rhabdomyosarcoma: a critical analysis of population-based incidence and survival data. Otolaryngol Head Neck Surg. 2011 Dec;145:967-973.
8. Sohaib SA, Moseley I, Wright JE. Orbital rhabdomyosarcoma — the radiological characteristics. Clin Radiol. 1998 May;53:357-362.
9. Shields JA, Shields CL. Rhabdomyosarcoma: review for the ophthalmologist. Surv Ophthalmol. 2003 Jan-Feb;48:39-57.
10. Jurdy L, Merks JH, Pieters BR, et al. Orbital rhabdomyosarcomas: A review. Saudi J of Ophthalmol. 2013 Jul;27:167-175.
11. Sun XL, Zheng BH, Li B, et al. Orbital rhabdomyosarcoma. Immunohistochemical studies of seven cases. Chin Med J (Engl). 1990 Jun;103:485-488.
12. Raney RB, Walterhouse DO, Meza JL, et al. Results of the Intergroup Rhabdomysosarcoma Study Group D9602 protocol, using vincristine and dactinomycin with or without cyclophosphamide and radiation therapy, for newly diagnosed patients with low-risk embryonal rhabdomyosarcoma: a report from the Soft Tissue Sarcoma Committee of the Children’s Oncology Group. J Clin Oncol. 2011 Apr;29:1312-1318.

About the Authors

Claire Kiernan, MD, is a resident physician in ophthalmology at the University of Tennessee Health Science Center, Hamilton Eye Institute, Memphis, Tenn. Her e-mail address is ckierna2@uthsc.edu.

Brian Fowler, MD, is an assistant professor of ophthalmology at the University of Tennessee Health Science Center, Hamilton Eye Institute, Memphis, Tenn.