Radiation-induced osteosarcoma following treatment of Ewing's sarcoma.

Radiation-induced sarcomas are a known, rare, complication from prior therapeutic radiation therapy. Radiation-induced sarcomas have been reported to have poor associated prognoses with increased morbidity and mortality when compared to primary sarcomas. In this case report, we discuss a 27-year-old female who presented at the age of 17 during pregnancy with an inability to bear weight and was subsequently diagnosed with Ewing's sarcoma of her femur. Adequate response to treatment was obtained with the initial treatment and the patient represented with acute, severe pain of her femur at the site of prior Ewing's. Extensive workup demonstrated radiation-induced osteosarcoma at the site of her prior Ewing's sarcoma in the radiation field. Multidisciplinary teams including orthopedics, pathology, medical oncology, and radiology are vital for appropriate and efficacious diagnosis of radiation-induced sarcomas. Despite the rarity of radiation-induced sarcoma, the ability to recognize and diagnose recurrent sarcoma is important for radiologists, particularly considering the associated poor prognosis. Early diagnosis and aggressive multidisciplinary treatment is crucial to improving patient morbidity and mortality. In this case, the diagnosis of radiation-induced osteosarcoma allowed expedited workup and initial aggressive, lifesaving treatment for our patient.