Postradiation malignant fibrous histiocytoma and osteosarcoma of a patient with high telomerase activities

BACKGROUND: An extremely rare case of postradiation malignant fibrous histiocytoma (MFH) and osteosarcoma (OS) secondary to radiation therapy for leukemia-related osteolytic lesions is presented. In addition, the telomere biology of these tumors was investigated. CASE REPORT: A 14-year-old boy was diagnosed with acute lymphocytic leukemia. The right tibia was irradiated at a total dose of 60 Gy, and the left tibia was irradiated at a total dose of 40 Gy. The left tibia developed MFH and the right tibia developed OS. RESULTS: Telomere reduction (MFH 70.2, OS 70.0%) and high telomerase activities (MFH 12.1, OS 17.7 TPG) were observed. These results reflect an aggressive feature of postradiation sarcomas. CONCLUSION: Prognosis for patients diagnosed with postradiation sarcoma is poor due to its aggressiveness. However, even if sarcoma occurs after irradiation in more than two fields in a single patient, improvements in prognosis are anticipated with appropriate chemotherapies and wide resection.