ABSTRACT
Ewing’s sarcoma and peripheral primitive neuroectodermal tumors (ES/PNET) arise from bone or soft tissue and affect predominantly children and young adults. They share the same histochemical staining profile and a unique nonrandom chromosome 22 rearrangement. They are grouped as the ES family of tumors. Cure of patients with ES/PNET has improved with multimodality approach, including surgery, radiation, and chemotherapy. Patients with localized ES/PNET will achieve an event-free survival (EFS) of 60-65% with current treatment protocols (1). However, 20-30% of patients with ES/PNET present with metastatic disease. Sites of metastases appear to affect outcome in EWS. Up to one-third of patients whose metastatic disease is limited to pulmonary and/or pleural metastases may become long-term survivors, whereas this rate drops to 20% in patients with bone and/or bone marrow metastases (1). Recurrent ES/PNET carries an even worse prognosis, where the EFS is !10% (2).
