Ewing Sarcoma
Overview
Plain-Language Overview
Ewing Sarcoma is a rare type of cancer that primarily affects the bones or the soft tissue around bones. It most commonly occurs in children and young adults, often involving the long bones like the femur or pelvis. This cancer causes a painful, growing lump or swelling and can lead to bone pain and fractures. It affects the skeletal system by destroying normal bone tissue and can spread to other parts of the body, such as the lungs. Early symptoms may include fever and fatigue, which can be mistaken for infection. The disease impacts health by weakening bones and causing systemic symptoms due to its aggressive nature.
Clinical Definition
Ewing Sarcoma is a highly malignant small round blue cell tumor of bone or soft tissue characterized by a specific chromosomal translocation, most commonly t(11;22)(q24;q12), resulting in the fusion gene EWSR1-FLI1. This fusion protein acts as an aberrant transcription factor driving oncogenesis. It primarily affects children and adolescents and is the second most common primary bone cancer after osteosarcoma. The tumor typically arises in the diaphysis of long bones or flat bones such as the pelvis. Clinically, it presents with localized pain, swelling, and systemic symptoms like fever. Histologically, it shows sheets of uniform small round cells with scant cytoplasm. The disease is aggressive with a high potential for metastasis, especially to lungs and other bones, making early diagnosis and treatment critical.