Ewing's sarcoma

Background

Ewing's sarcoma is a poorly differentiated tumor derived from a primitive neuroectodermal cell. It occurs most commonly within bones, but may also be seen in extraosseus locations. There are approximately 2.1 cases of Ewing's sarcoma per 1 million Caucasian children under 15 years of age in the US. The disease is extremely rare in African–American and Asian children. Seventy percent of all patients with Ewing's sarcoma are under 20 years of age. The peak incidence of Ewing's sarcoma is in females from 11 to 12 years of age and males from 15 to 16 years of age. Seventy percent of patients with localized disease treated with multimodality therapy will be alive 5 years after treatment. In contrast, the 5-year event-free survival for patients with metastatic disease is only 25%.

Diagnosis

The most common presenting symptoms of Ewing's sarcoma are pain and localized swelling at the site of disease. The pain is initially intermittent but later progresses to constant pain that typically wakes the patient at night. Patients may also present with systemic symptoms such as weight loss and fever. The erythrocyte sedimentation rate is commonly elevated. Three percent of patients will be diagnosed because of paraplegia. Ewing's sarcoma is frequently mistaken for osteomyelitis as both diseases cause similar initial symptoms. Patients with such symptoms should therefore be questioned about recent dental procedures, as actinomycosis of the bone can be radiographically and clinically similar to Ewing's sarcoma.