Abstract
A 60-year-old man with a history of radiation therapy 28 years ago for a benign disease (an aneurysmal bone cyst) was admitted with dyspnea and dysphagia. Computed tomography showed an 8-cm tumor invading the trachea and esophagus. His condition declined rapidly, and he died on day 27 of hospitalization. Autopsy revealed radiation-induced osteosarcoma. Radiation-induced sarcoma can develop even after radiotherapy for benign diseases, in which case the latency period might be longer. Furthermore, the prognosis depends on the location of the resectable tumor. Therefore, longer-term internal imaging follow-up should be performed after radiotherapy for benign diseases to detect early-stage sarcoma.