CLEAR-CELL CHONDROSARCOMA OF RIB FOLLOWING REPETITIVE LOW-IMPACT TRAUMA

A case of clear cell chondrosarcoma of the rib in a 30-year-old man is described. The tumor developed at the site of repetitive low-impact t rauma (on the arm of a wheelchair) over a period of 24 years. An assoc iation between chondrosarcoma and external trauma has not been previou sly reported. Chondrosarcoma has been described in previously irradiat ed bone and in Paget's disease. In both these examples there is an inc rease in new bone formation associated with necrosis of bone and incre ased resorption of bone, respectively. A possible mechanism in our cas e is increased new bone formation elicited by repeated microfractures of trabeculae of rib bone.