MRI differentiation of low-grade and high-grade chondrosarcoma of the shoulder girdle, chest wall and pelvis: a pictorial review based on 111 consecutive cases.

Approximately 40% of conventional chondrosarcomas arise from the shoulder girdle, chest wall and pelvis. This pictorial review describes the MRI features which may aid in the differentiation of Grade 1 chondrosarcoma (Gd1-CS) from high-grade chondrosarcoma (HG-CS) and dedifferentiated chondrosarcoma (DD-CS) in these locations, based on literature review and assessment of 111 consecutive cases presenting to the senior authors institution over a 13-year period. Of the 111 patients reviewed (71 males and 40 females; mean age 54.3 years; range 17-92 years), 27 were Gd1-CS, 72 were HG-CS and 12 were DD-CS. Tumours arising from the scapula, acetabulum, pubis/ischium and sacrum were more likely to be HG-CS, as were intramedullary tumours. MRI features associated with HG-CS and DD-CS included cortical destruction, bone oedema, soft tissue oedema, tumour necrosis, intermediate T2W SI and joint invasion. The presence of a soft tissue mass became a significant differentiating feature for tumours arising within the medullary cavity, but this was location-specific and did not differentiate between Gd1-CS and HG-CS/DD-CS arising from the sternum or clavicle.