Purpose: Second malignant neoplasms (SMNs) are a rare occurrence after the successful treatment of childhood cancer. For survivors of Wilms' tumor, the 10-year cumulative 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 sarcoma 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 intrathoracic 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 therapy with no evidence of disease.
Conclusions: This is the first report to our knowledge of Ewing's sarcoma arising in the irradiation field of a patient treated previously for Wilms' tumor.