Mediastinal osteosarcoma with extension to lungs in a patient treated for Hodgkin's disease.

This article reports a patient with Hodgkin's disease in remission after combined modality therapy who developed metastatic pulmonary osteosarcoma, subsequently found to originate in soft tissue of the mediastinum, within a field irradiated 11 years previously. This patient developed a series of radiotherapy-induced complications in addition to osteosarcoma. Only 16 cases of extraskeletal osteosarcoma after radiation treatment have been reported, none originating in the mediastinum. To the authors' knowledge, this is the first reported case of extraskeletal osteosarcoma occurring in a patient previously treated for Hodgkin's disease and with the sarcoma originating within the irradiated field.