Ewing’s Sarcoma of the Mandible in a Paediatric Patient: Diagnostic Challenges and Multimodal Management

Abstract Ewing’s sarcoma (ES), a rare, aggressive malignancy of the Ewing sarcoma family, predominantly affects long bones, with mandibular involvement accounting for < 1% of cases. We present a 7-year-old female with progressive right mandibular swelling, trismus, and tooth mobility. Contrast-enhanced CT revealed a 5.8 × 4.3 cm lobulated expansile mass involving the right mandibular ramus/body, with cortical destruction, cystic/necrotic areas, and soft tissue invasion into the oral cavity. Radiological differentials included odontogenic myxoma, ameloblastoma, and fibrous dysplasia. Histopathology demonstrated small round blue cells with CD99/FLI-1 positivity, while FISH/RT-PCR confirmed the EWSR1-FLI1 fusion, securing the ES diagnosis. Due to rapid tumour progression and functional impairment, segmental mandibulectomy with titanium miniplate reconstruction was performed, followed by adjuvant radiotherapy (50 Gy) and chemotherapy (VAC/IE regimen). This case highlights the diagnostic challenges of mandibular ES, which mimics benign lesions, necessitating early integration of advanced imaging, molecular studies, and histopathology. A literature review underscores the rarity of paediatric mandibular ES, emphasizing interdisciplinary collaboration and multimodal therapy for optimal outcomes. This report advocates for tailored treatment protocols to balance oncologic control with functional outcomes in anatomically complex paediatric cases.