Patient with recurrent Ewing sarcoma and status post hemipelvectomy. Please reevaluate BONE AND BONE MARROW: Similar postsurgical changes are again observed involving the right internal hemipelvectomy 2011, including portion of the right iliac wing and ischium resection and superior displacement of the femoral head. Correlation of the osseous structures and prior exams are similar, including deformity of the femoral head. Scattered postsurgical changes including susceptibility artifact and soft tissue deformity appear unchanged in contour and gross appearance. Specifically the surgical incision scar is noted along the right paraspinal musculature extending anterolaterally.And irregular shaped focus of abnormal signal intensity involving the right ischium again appears similar to the prior study with an abnormal signal intensity seen in the right sacral wing. Suspected post treated tumor with mild heterogeneity of the remaining bone marrow appears similar compared to prior studies and again suggesting red marrow recruitment.SOFT TISSUES: Of special note is the abnormal enhancement and signal characteristics observed within the right adductors and piriformis anteriorly and gluteus maximus posteriorly. The edema like appearance remains similar to 11/28/14 and again without a discreet focal mass observed, yet there is a loss of muscle bundle distinction with mild enlargement/fullness without clear evidence of encapsulation. No clear distinct changes to suggest internal hemorrhage. The appearance remains most suggestive of post treatment changes and overall stability from past November.JOINTS: Status post hemipelvectomy and pseudoarticulation appears similar. Suspected reactive synovitis like changes involving the residual articulation. Left hemipelvis is intact.
Extensive postoperative changes as described similar to prior exam. Surrounding edema and enhancement of right hip muscles remain uncertain but presumably related to prior treatment and possibly radiation. No new focal mass or discrete lesion/changes are observed.