Abstract
BACKGROUND: Ewing sarcoma (ES) is a malignant small round-cell tumor that typically arises in the bones or soft tissue of children and young adults. Although most cases involve the skeletal system, extraskeletal presentations are less common, especially involving visceral organs. Primary cardiac ES is exceptionally rare, with only a limited number of cases reported in the literature. CASE PRESENTATION: A 27-year-old male presented with symptoms including cough, dyspnea, fever, anorexia, night sweats, and weight loss. Clinical and imaging evaluations revealed a mass anterior to the right ventricular outflow tract (RVOT), which was ultimately diagnosed as primary extraskeletal cardiac ES. The patient was treated with a comprehensive multimodal approach, incorporating surgical resection, chemotherapy, and radiotherapy. Remarkably, he survived for 36 months after diagnosis, surpassing the survival durations reported in most previous cases. CONCLUSION AND KEY CLINICAL MESSAGE: A prolonged survival outcome was demonstrated in this rare case of cardiac ES through aggressive multimodal therapy. Although rare, ES should be included in the differential diagnosis of intracardiac tumors, especially in younger patients presenting with systemic symptoms, to facilitate timely diagnosis and intervention.