{Reference Type}: Case Reports {Title}: Extraosseous Ewing Sarcoma With Upper Gastrointestinal Bleeding. {Author}: Yadav AK;Shrestha M;Rajbhandari S;Kafle R;Shrestha S;Khadka D;Poudel S;Paudel M; {Journal}: ACG Case Rep J {Volume}: 11 {Issue}: 8 {Year}: 2024 Aug 暂无{DOI}: 10.14309/crj.0000000000001447 {Abstract}: Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) is a type of malignancy that usually appears as a tumor in the bone. However, in a few patients with ES/PNET, it can occur outside of the bone. Although extraosseous ES/PNET can appear in various parts of the body, involvement of small bowel is rare. If it does, it can present with vague abdominal pain and gastrointestinal bleeding. This case report presents a 28-year-old gentleman with extraosseous ES/PNET in the duodenum who experienced gastrointestinal bleeding as a presenting symptom.