Intramedullary mass lesion in the right iliac wing with surrounding bone marrow edema. The lesion breaks though the medial cortex. Edema in the adjacent portion of the iliacus muscle and in the gluteus minimus muscle. The lesion measures 8 x 32 mm, perilesional edema excluded. Both the lesion and the perilesional edema enhance following contrast injection.
No involvement of the acetabular roof or right sacroiliac joint identified.
No soft tissue mass emanating from the bone.
No excessive fluid in the femoroacetabular joints.
Summary: mass lesion in the right iliac wing, as described above. Ewing sarcoma cannot be ruled out; a biopsy is mandated.