Ewing's Sarcoma as a Second Malignant Neoplasm in a Child Previously Treated for Wilms' Tumor

Purpose: Second malignant neoplasms (SMNs) are a rare occurrence after the sucessful treatment of childhood cancer. For survivors of Wilms' tumor, the 10-year cumultative risk of developing an SMN has been estimated to be 1%. Bone sarcomas arising within the radiation field are a common occurrence, yet Ewing's sarcom has been rarely reported as an SMN. Patients and Methods: A 10-year-old girl presented with dyspnea 5 years after the diagnosis of stage III favorable histology Wilms' tumor and was found to have a right ntrathoracic mass arising from the eighth and ninth ribs. The mass was located at the edge of the previous radiation field. Results: Tumor cytogenetics and immunocytochemistry were helpful in establishing the diagnosis of Ewing's sarcoma. Treatment included combination chemotherapy, with hematopoietic growth factor support, and excluded anthracyclines and radiotherapy. More than 1 year after the diagnosis of Ewing's sarcoma, the patient has completed with no evidence of disease. Conclusions: This is first report to our knowledge of Ewing's sarcoma arising in the irradiation field of a patient treated previously for Wilms' tumor