Primary extraskeletal Ewing’s sarcoma of the diaphragm in an adolescent male: a surgical case report

Introduction: Extraskeletal Ewing’s sarcoma (EES) of diaphragmatic origin is exceptionally rare, with few cases documented. Preoperative diagnosis is challenging due to overlapping clinical and radiologic features with more common hepatic and retroperitoneal pathologies. Case presentation: A 17-year-old male presented with dyspnea, abdominal distension, and subacute intestinal obstruction. Imaging suggested a large cystic hepatic lesion. Exploratory laparotomy revealed a vascular diaphragmatic tumor with metastatic seedlings. Definitive resection via right posterolateral thoracotomy included partial diaphragm and rib excision with polypropylene mesh reconstruction. Histopathology and immunohistochemistry confirmed EES. Molecular confirmation using fluorescence in situ hybridization (FISH) demonstrated EWSR1 gene rearrangement. Adjuvant multi-agent chemotherapy and radiotherapy were administered, following the vincristine-doxorubicin-cyclophosphamide alternating with ifosfamide-etoposide (VDC/IE) regimen and conformal intensity-modulated radiotherapy (IMRT) to 45 Gray. At 10-month follow-up, the patient remained in complete remission. Discussion: Diaphragmatic EES presents unique diagnostic and surgical challenges due to its location and proximity to vital structures. Complete surgical excision with functional reconstruction, combined with multimodal adjuvant therapy, offers the best potential for local control and long-term survival. Vigilant surveillance is necessary given the early recurrence risk. Conclusion: EES should be considered in the differential diagnosis of large diaphragmatic masses. Coordinated multidisciplinary management enables effective treatment, and detailed reporting of such presentations enhances the collective understanding of rare tumor sites.