Clinical features: 1. Benign cartilage tumors occurring in bone, located in the medullary cavity, consisting of foliated mature glassy cartilage with mature cell differentiation, small slightly dark-stained nuclei and no heterotypy. 2. It is commonly found in short bones of hands and feet, and proximal phalanges are the most common. 3, manifested as painless swelling, pain may appear in case of malignant or pathological fracture. 4. Very rare malignant change. Indications for surgery: 1. Deformity is obvious. 2.The risk of pathologic fracture or pathologic fracture is high. 3. Malignancy is suspected. 4. Significant pain. Surgical method: Scraping and bone grafting, if scraping is complete, rarely recurrence.