[28-year-old male patient with hip pain, history of Ewing's sarcoma. Evaluate for cause.] [There is a large mass which appears to be arising off or involving the left superior pubic ramus. The mass demonstrates low T1 signal, heterogeneous high signal on T2-weighted images, and has heterogeneous enhancement on postcontrast imaging consistent with tumor. Furthermore, confluent with the mass is a centrally low signal intensity, peripherally enhancing component which may represent necrotic tumor. Overall, the solid and cystic components of the mass measure 8.0 x 6.8 x 8.3 cm (AP by transverse by craniocaudal). Signal abnormality extends into the anterior column of the left acetabulum. New abnormal T2 signal within the left ilium also likely represents tumor. Abnormal signal intensity within the right sacrum is not significantly changed from the prior study. Redemonstration of postsurgical changes of a resection of the right ilium with superior displacement of the femoral head, which is now flattened in contour and irregular. Tubular focus of signal abnormality within the femoral head likely represents surgical intervention. There is abnormal signal extending from the right lesser trochanter into the intertrochanteric region which is more apparent on this examination compared to priors and could represent tumor.There is edema type signal within the bilateral hip adductor musculature, right greater than left, and the right gluteus muscles. There is generalized atrophy of the muscle on the right.
[Tumor progression with a large mass within the left hemipelvis and multiple sites of osseous involvement.