Radiation-Induced Dedifferentiated Chondrosarcoma With Orbital Invasion

PURPOSE: To report 2 interventional cases of dedifferentiated chondrosarcoma with orbital involvement after radiotherapy performed in childhood and to review the literature on chondrosarcoma in the orbit following radiation treatment. METHODS: Retrospective analysis of medical records of 2 patients with chondrosarcoma of the orbits with review of the literature. RESULTS: The first patient developed chondrosarcoma of the orbital and maxillary sinus 36 years after external beam radiation therapy to the OS to treat retinoblastoma. The second patient developed a large orbital chondrosarcoma 35 years after external beam radiation therapy in the treatment of craniofacial fibrous dysplasia. CONCLUSIONS: These cases highlight the risk of secondary chondrosarcoma in patients following radiotherapy and the importance of lifetime monitoring.