Clear cell chondrosarcoma of the pelvis in a skeletally immature patient

We report on a case of clear cell chondrosarcoma (CCCS) of the left iliac b one in a 12-year-old skeletally immature boy. Radiographic examination reve aled an aggressive osteolytic lesion with areas of mineralization. Fluid-fl uid levels were seen on T2-weighted MR images. Laboratory data showed sligh t elevation of serum alkaline phosphatase. The biopsy specimen showed histo logical features of CCCS with some resemblance to osteosarcoma, such as pro minent irregular osteoid formation among clear tumor cells. Surgical treatm ent was accomplished without pre- or post-operative chemotherapy. Because o f the patient's age, elevated serum alkaline phosphatase, and histopatholog y with prominent osteoid production, this case could be confused with osteo sarcoma. Although CCCS is an extremely rare bone tumor in children, it is i mportant to be aware that it may arise in a skeletally immature patient. CC CS, unlike osteosarcoma, is not treated with neo-adjuvant chemotherapy.