chondrosarcoma (MONDO_0008977) is a malignant cartilaginous matrix-producing mesenchymal neoplasm arising from the bone and soft tissue. It usually affects middle-aged to elderly adults. The pelvic bones, ribs, shoulder girdle, and long bones are the most common sites of involvement. Most chondrosarcomas arise de novo, but some may develop in a preexisting benign cartilaginous lesion. Also known as: chondrosarcoma (disease), chondrosarcoma, malignant, chondrosarcoma, somatic mutation.