Background <p>Ewing’s sarcoma (ES) is a common malignant bone tumor in adolescents and young adults. Its pelvic location is associated with a worse prognosis. Our case represents one of the rare instances in the literature involving an adult patient in whom the disease progressed fatally due to cardiac extension.</p> Case presentation <p>We report the case of a 31-year-old female patient who initially presented with swelling in her right lower extremity, which was found to be caused by deep venous thrombosis (DVT) extending from the iliac vein to the inferior vena cava. A thoracic-abdominal CT scan, performed as part of the etiological workup, revealed a tumor in the right hip bone with a malignant appearance, exhibiting both endo and exopelvic extension, and extending to the inferior vena cava (IVC) and right heart chambers. An echo-guided biopsy of the tumor mass confirmed Ewing's sarcoma. The patient's condition rapidly deteriorated, leading to death due to the inoperability of the extensive tumor.</p> Conclusions <p>Ewing’s sarcoma can affect adults, presenting with late-onset or rapidly metastatic forms. In its extensive form, ES requires multimodal imaging to assess operability and is associated with a poor prognosis. This case report represents one of the rare instances in the literature of Ewing’s sarcoma metastasizing to the heart.</p>