Ewing's sarcoma

Definition:

A specific type of bone tumor.

Causes, incidence, and risk factors:

Ewing sarcoma occurs during the rapid bone growth that generally occurs during puberty. It is seldom seen before a child is 10 years old. The tumor may arise in the long bones of the extremities, most often in the femur (thigh bone) or the pelvis. It may also develop in the skull or the flat bones of the trunk. This type of tumor is almost never seen in black children.

Clinical symptoms are few. The most common is pain and occasionally swelling at the site of the tumor. Fever may also be present and is considered an unfavorable prognostic sign. The tumor spreads easily (metastasis), often to the lungs and other bones. Metastasis is present in approximately one-third of the children at the time of diagnosis.