Figure 3: (a) Preoperative anteroposterior radiograph of the pelvis of a 28-year-old female who had osteosarcoma of the acetabulum and ilium. ((b) and (c)) Gadolinium-enhanced axial T1-weighted MRI showing the tumor arising in the acetabulum and ilium. After neoadjuvant chemotherapy, the patient underwent tumor wide resection and endoprosthetic reconstruction with no postoperative major complications. (d) Postoperative radiograph 3 years after endoprosthetic reconstruction.