Oman Journal of Ophthalmology

: 2022  |  Volume : 15  |  Issue : 2  |  Page : 228--230

Wolf in sheep's clothing: Primary orbital Ewing sarcoma in a child masquerading as internal angular dermoid

Teena Mariet Mendonca1, Harsha Prasada Lashkari2, Pooja K Suresh3, Rahul Kondaveti1, Faraz Ali4, Gladys R Rodrigues1,  
1 Department of Ophthalmology, Kasturba Medical College, Mangalore Manipal Academy of Higher Education Manipal, Kozhikode, Kerala, India
2 Division of Pediatric Hematology/Oncology, Department of Pediatrics, Kasturba Medical College, Mangalore Manipal Academy of Higher Education Manipal, Kozhikode, Kerala, India
3 Department of Pathology, Kasturba Medical College, Mangalore Manipal Academy of Higher Education Manipal, Kozhikode, Kerala, India
4 Consutant, Oculoplasty and Ocular Oncology Services Malabar Super-Speciality Eye Hospital, Kozhikode, Kerala, India

Correspondence Address:
Dr. Teena Mariet Mendonca
Department of Ophthalmology, Kasturba Medical College Hospital, Manipal Academy of Higher Education, Manipal - 575 001, Karnataka


Ewing sarcoma is one of the rare, highly malignant neuroectodermal tumors frequently involving bones. Primary orbital Ewing sarcoma is extremely uncommon. We report a rare case of a 5-year-old boy who presented to us with a painless, slow-growing mass above the medial canthus of the left eye, the clinical appearance of which was masquerading as an internal angular dermoid. The child was subsequently diagnosed to have primary orbital Ewing sarcoma. Primary orbital Ewing sarcoma is a rare tumor with poor prognosis, poses diagnostic challenges, and demands a high index of clinical suspicion.

How to cite this article:
Mendonca TM, Lashkari HP, Suresh PK, Kondaveti R, Ali F, Rodrigues GR. Wolf in sheep's clothing: Primary orbital Ewing sarcoma in a child masquerading as internal angular dermoid.Oman J Ophthalmol 2022;15:228-230

How to cite this URL:
Mendonca TM, Lashkari HP, Suresh PK, Kondaveti R, Ali F, Rodrigues GR. Wolf in sheep's clothing: Primary orbital Ewing sarcoma in a child masquerading as internal angular dermoid. Oman J Ophthalmol [serial online] 2022 [cited 2022 Nov 28 ];15:228-230
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Full Text


Ewing sarcoma family of tumors (ESFTs) are highly malignant tumors of neuroectodermal origin primarily arising from bone.[1] ESFTs include primitive neuroectodermal tumors (PNET) and Ewing sarcoma as they belong to family of small round cell tumors which share common characteristics of having CD99 protein expression.[1] Commonly seen in while males with peak incidence in the second decade, these tumors usually present in the lower limbs, pelvis, and chest.[2] The incidence in head and neck region is found to be <4%.[2],[3],[4] Primary orbital Ewing sarcoma is found to be extremely rare.[5],[6] There are less than 50 cases of primary orbital Ewing sarcoma reported in literature.[4],[6] Our case is a rare orbital presentation of Ewing sarcoma involving the left orbit in a 5-year-old boy.

 Case Report

A 5-year-old boy presented with a painless swelling over the medial aspect of left upper eyelid for 6 months. There was no history of decreased vision, proptosis, headache, fever, and other associated symptoms.

On examination, the best-corrected visual acuity in both eyes was 20/20. Anterior segment and fundus examination were normal in both eyes. In the left eye, a globular swelling was present superior to medial canthus measuring 1.5 cm × 2 cm [Figure 1]a. The swelling was nontender, had smooth surface, and firm in consistency. The swelling was adherent to the underlying bone. The swelling was suspected to be internal angular dermoid by many ophthalmologists before the presentation to our center.{Figure 1}

Laboratory investigation including complete blood count and serum lactate dehydrogenase levels were normal. A contrast-enhanced computed tomography (CT) section through the orbit showed a cystic lesion with thick enhancing walls devoid of calcification confined to the anterior part of superomedial orbit without adjacent bone erosions or orbital invasion [Figure 1]b.

He underwent excision biopsy of the mass under general anesthesia. Gross examination of the specimen showed a nodule measuring 2 cm × 2 cm × 1.5 cm. Outer surface was dark brown and cut surface was solid, dark brown infiltrative friable tumor. Histopathological examination revealed small round tumor cells arranged in sheets, nests, and cords [Figure 2]. The tumor cells are round, uniform, and have scant cytoplasm and hyperchromatic nucleus. Periodic acid-Schiff stain shows coarse magenta granules in the cytoplasm. Furthermore, immunohistochemical stain showed strong membrane positivity with CD99 and vimentin and focal cytoplasmic positivity for synaptophysin (syn), leukocyte common antigen, terminal deoxynucleotidyl transferase, desmin, smooth muscle actin, and chromogranin were negative in tumor cells. These histological features along with histochemical and immunohistochemical stains established the diagnosis of extraskeletal Ewing sarcoma. However, the resected tumor margins were positive for malignant cells. Thorough systemic evaluation and positron emission tomography scan showed a single hotspot in the left orbit with no systemic involvement or metastasis. Hence, the diagnosis of primary orbital Ewing sarcoma was made. The patient underwent chemotherapy for 14 cycles as per the Euro Ewing 2012 protocol with vincristine, ifosfamide, doxorubicin, and etoposide induction. He was disease-free for 18 months. Following nine cycles of chemotherapy, response assessment did not show any residual disease in the orbit. However, in view of margins, positivity on histopathology, local radiotherapy (50.4 Gy) was given with concomitant chemotherapy. Following 6 months of the completion of chemoradiotherapy, he was diagnosed to have pulmonary and intracranial metastasis. The patient is currently undergoing palliative chemotherapy.{Figure 2}


Clinically, primary orbital Ewing sarcoma patients often present with localized pain, proptosis, and eyelid swelling associated with systemic symptoms such as fever, fatigue, weight loss, or anemia.[4],[6] Our patient presented with a painless, palpable swelling in the left eye superior to the medial canthus with no other systemic features. In a case series published by Kaliki et al., out of 12 cases of orbital Ewing sarcoma, majority of the patients presented with proptosis and swelling of upper eyelid. In their series, the location of the tumor was mostly seen in the superior-lateral part of orbit with just one case having the epicenter in the medial orbit similar to our patient.[6]

In our case, the location of the mass which was superior to the medial canthus poses challenges in diagnosis with differentials involve, internal angular dermoid, frontal mucocele, and neoplasms. Superomedial orbit is a more common location for rhabdomyosarcoma in the first decade of life. Metastatic neuroblastoma could also be a clinical differential diagnosis in our patient.

CT scans and other radiographic modalities such as magnetic resonance imaging, although helpful in assessing the site of the mass do not play an essential role in the definitive diagnosis of Ewing sarcoma. Nonenhancing, soft tissue mass with adjacent needle-like bony reaction is commonly reported.[7] However; our patient had no bony reaction on CT scan.

Ewing sarcoma is known for its aggressive nature and exhibits poor prognosis. The tumor metastasis may occur to adjacent bone by direct spread thereby causing local extension to sinuses and nasal cavity. Intracranial metastasis and hematogenous spread to bone marrow and retroperitoneal lymph nodes are reported.[6] However, in our patient, the tumor was diagnosed successfully at an early stage and timely surgical excision was performed. He did not have any systemic involvement at the time of diagnosis and was disease-free for 18 months after surgery. The patient had received extensive chemotherapy and adjuvant radiotherapy after surgical excision, which has been considered the mainstay treatment of Ewing sarcoma.[8] However, the patient developed lung and intracranial metastasis and is currently on palliative chemotherapy.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The Guardian understands that names and initials will not be published and due efforts will be made to conceal patient identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


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