Name : Hamid Reza
Family : Haghighatkhah
Resident : Pouya Ziai
Gender : Male
Age : 10
10 Y/O boy with
Imaging Procedures and Findings
Plain radiography: Mixed lytic and sclerotic lesion in inferior ramus of the left pubis plus adjacent soft tissue mass
CT: Soft tissue mass with necrotic foci which has extended to ischiorectal space; rectum and urethra are compressed.
MRI: Iso-signal soft tissue mass in T1-weighted images and heterogenous high-signal mass in T2-weighted images
STIR: High-signal bone marrow signal change in favor of edema
Ewing??s sarcoma has a predilection for the long bones (younger children) and pelvis (older children). MRI facilitates staging of Ewings sarcoma and is better than CT for demonstrating bone marrow and soft tissue involvement. MRI signal intensity characteristics of this tumor are not specific and are similar to those of other malignant neoplasms. The tumors signal intensity is lower than or equal to that of muscle on T1-weighted images and is higher in T2-weighted images. High signal intensity on T2-weighted images after treatment does not always indicate a poor response, since it may represent necrosis, reactive granulation tissue, or hemorrhage. Plain radiographs: Onion skin periosteal new bone formation.
Haaga JR. CT and MRI of the whole body, 5th edition.