Female 64 years old Reason: evaluate for response/progression History: radiation induced osteosarcoma The left ilium has abnormal low T1 and patchy high T2 signal with a surrounding soft tissue mass, extending anteriorly and posteriorly, which demonstrates irregular peripheral enhancement consistent with known osteosarcoma. The soft tissue mass is significantly increased in size compared to the prior exam measuring approximately 4.9 x 3.4 cm in axial dimensions (series 701, image 44). There is also edema in the musculature surrounding this soft tissue mass. No new foci suspicious for malignancy are identified.In the right ilium, adjacent to the sacroiliac joint there is linear decreased signal with associated increased signal abnormality on fluid sensitive sequences indicating an insufficiency fracture, similar to the prior exam. There is similar signal abnormality indicating a insufficiency fracture in the right sacrum adjacent to the sacroiliac joint.
1.Left iliac wing osteosarcoma significantly increased in size compared to prior exam.2.Insufficiency fractures adjacent to the right sacroiliac joint as detailed above.