Rare complication of breast cancer irradiation: postirradiation osteosarcoma. 
Radiation-induced osteosarcoma is a rare complication of radiation therapy for breast cancer.  The authors present a 60-year-old patient in whom osteosarcoma of the chest wall developed 5 years after modified radical mastectomy and radiation therapy for breast cancer.  One year after resection of the chest osteosarcoma, metastasis to the contralateral axillary lymph nodes developed and these were removed.  Radiation-induced osteosarcoma is difficult to treat and has a poor prognosis, thus early diagnosis is necessary for optimal treatment.