Presentation
Right loin pain.
Patient Data
Lobulated sessile bone exostosis arising from the right iliac bone which demonstrates continuity with the native medullary cavity.
At the superior part of the aforementioned bone exostosis there is large multiloculated irregular shaped cartilaginous cap, exhibiting bright signal intensity on T2/STIR images and dark signal intensity on T1 images. On post contrast study it shows heterogeneous, irregular peripheral enhancement.
It extends to the abdominal cavity reaching the sub hepatic area and exerting significant mass effect upon the surrounding bowel loops, right psoas muscle and right anterior abdominal wall muscles.
Multiple rings and arcs calcification, in keeping with chondroid matrix.
Case Discussion
Radiological features are mostly in keeping with secondary chondrosarcoma, arising from pre-existing osteochondroma.