Beyond the Bones: A Case Report of Extraosseous Ewing Sarcoma

Ewing sarcoma (ES) is primarily recognized as a primary bone tumor; however, its extraosseous variant is exceptionally rare and presents unique clinical challenges. In this article, we report the case of a 22-year-old male who initially presented with abdominal swelling. Diagnostic tests included abdominal imaging and a CT scan, revealing a solid liver mass. A thorough evaluation confirmed it to be an extraosseous ES, supported by liver biopsy and immunohistochemistry demonstrating positive expression for AE1/AE3 and CD-99, along with genetic analysis revealing a rearrangement of the EWSR1 gene (translocation 22q12). The patient’s treatment involved a multimodal approach, including perioperative chemotherapy, surgery, and postoperative chemotherapy, following which the patient remained in complete remission after 24 months. This case emphasizes the importance of considering rare malignancies such as ES in differential diagnoses for young patients with liver masses. It also accentuates the pivotal role of family physicians in early detection and holistic patient care, underscoring the need for comprehensive investigations when encountering persistent symptoms.