The diagnosis and treatment of malignant cartilage tumors of bone are difficult for the orthopedic surgeon and pathologist because the clinical and biological behavior of the tumor does not always correlate with the histology. Little is known about the biochemistery and metabolism of cartilage tumors. This proposal is based on the hypothesis that the biochemical and metabolic characteristics of the chondrosarcoma may provide a better basis for classification and prediction of behavior then the currently available methods and may also provide clues as to newer methods of therapy. This study proposes to prove this hypothesis by analysing surgically obtained specimens of benign and malignant cartilage tumors by a variety of histologic, histochemical, biochemical, and metabolic techniques in an effort to establish a "biological profile" for the lesions. Following obtaining of these data, one or several aspects of the biological profile may be found to serve as a predictor of clinical behavior of the lesion and thus establish biochemical tests which we observe as indicators of the benign or malignant state. On the basis of the biological process certain techniques of treatment will be studied using in vitro systems. These may serve to find a more effective method of treatment for the malignant cartilage lesions.