Ewing sarcoma is a rare type of cancer that primarily affects children and young adults. It usually develops in the bones or soft tissues, particularly in the arms, legs, and pelvis. The exact cause of Ewing sarcoma is not well understood, but it is believed to arise from changes in the DNA of cells, leading to uncontrolled growth. Symptoms of Ewing sarcoma can include pain, swelling, and tenderness in the affected area. Sometimes, patients may experience fever or fatigue. Early diagnosis and treatment are crucial, often involving a combination of chemotherapy, radiation therapy, and surgery to improve outcomes.