Rib-Origin Ewing Sarcoma With Cranial Nerve Involvement From Orbital Metastasis: A Rare Case Report

Area of Science:

• Oncology
• Pathology
• Medical Imaging

Background:

• Ewing sarcoma (ES) is an aggressive bone tumor in young adults, often originating in the pelvis or long bones.
• It is characterized by the EWSR1-FLI1 fusion gene due to a specific chromosomal translocation.
• While lung metastasis is common, orbital and cranial involvement is exceptionally rare.

Purpose of the Study:

• To report a rare case of Ewing sarcoma with unusual orbital and cranial involvement.
• To emphasize the importance of early detection and aggressive treatment for improving patient outcomes in ES.
• To highlight the diagnostic utility of immunohistochemistry in resource-limited settings.

Main Methods:

• Case report of a 23-year-old male with progressive shortness of breath, chest swelling, and proptosis.
• Diagnostic imaging included Computed Tomography (CT) and Magnetic Resonance Imaging (MRI).
• Histopathological analysis involved CT-guided biopsy, immunohistochemistry (CD99, NKX2.2), and Ki-67 index assessment. Pleural fluid analysis was also performed.

Main Results:

• The patient presented with a large chest mass, pleural effusion, and orbital mass causing proptosis and diplopia.
• Initial pleural fluid analysis mimicked tuberculosis but biopsy confirmed small round blue cell tumor.
• Immunohistochemistry confirmed Ewing sarcoma with a high Ki-67 proliferation index.

Conclusions:

• Ewing sarcoma with orbital and cranial involvement is a rare but critical presentation.
• Prompt diagnosis and multimodal therapy (chemotherapy, radiation, surgery) are vital for survival.
• Immunohistochemistry plays a key role in diagnosing ES, particularly in resource-limited environments.