1. Mesenchymal chondrosarcoma is an unusual tumor which has a characteristic morphological appearance. The neoplasm arises mostly from the flat bones and frequently metastasizes, sometimes after a lapse of many years.
2. Of particular interest is the report of two examples in which the tumor arose in extra-osseous tissues.
3. Radical surgical removal is the treatment of choice because of the tendency of the neoplasm to recur locally and to metastasize.