A morphologic variant of chondrosarcoma arising from bone and soft tissue. It is characterized by the presence of malignant small round cells, biphasic growth pattern, and well differentiated hyaline cartilage. Clinical presentation includes pain and swelling. The clinical course is aggressive, with local recurrences and distant metastases. The disease is Monarch Disease Ontology entry MONDO_0006853 (mesenchymal chondrosarcoma).