Primary retroperitoneal extraskeletal mesenchymal chondrosarcoma: a computed tomography diagnosis.

Mesenchymal chondrosarcomas, although very rare compared with conventional chondrosarcomas, are one of the few primary malignant tumours of bone that sometimes also arise in the soft tissues. Here we present a rare case of retroperitoneal extraskeletal mesenchymal chondrosarcoma (ESMC) in a 50-year-old female that showed characteristic extensive calcification. In this report, we discuss CT features of ESMC with pathological correlation.