Sarcomatous Degeneration in Fibrous Dysplasia of the Rib Cage

Malignant degeneration in fibrous dysplasia is a rare occurrence. Most cases are reported in polyostotic fibrous dysplasia with predisposition of the femur, tibia, maxilla, and mandible. The most commonly observed malignant tumors are osteosarcoma, fibrosarcoma, and chondrosarcoma. We describe a case of a low-grade osteosarcoma occurring in polyostotic fibrous dysplasia of the rib cage in a 50-year-old man.