Post-radiation Osteosarcoma

Fibroblastic osteosarcoma involving a rib in a 62 y/o female who received radiation therapy for recurrent breast cancer. Delicate lace-like osteoid deposits are seen in the center of the image. Necrosis is seen at the extreme left. Besides osteosarcoma, other malignancies that may involve the bone following radiation exposure include fibrosarcomas, malignant fibrous histiocytomas, chondrosarcomas, angiosarcomas, and malignant lymphomas.