Extraskeletal masses are chondrosarcomas. Central chondrosarcoma is a chondrosarcoma that originates from within the bone. The main symptom is deep pain that is not intense and non-persistent. In the progressive stage of the tumor, large spherical extraosseous masses may form. There are distinct sites of predilection, in order of predilection, for the femur (especially proximal), pelvis, proximal humerus, scapula, and proximal tibia. The other bones of the trunk, the radius, the ulna, the foot, and the hand are the less frequent sites of softness (chondromas are common in the hand and less common in the trunk bones). Prevention methods for extraosseous masses: 1. Maintain an ideal body weight. 2.Intake a variety of foods. 3. Include a variety of vegetables and fruits in your daily diet. 4, consume more high fiber foods (such as whole grain cereals, legumes, vegetables, fruits). 5.Reduce the total intake of fat. 6.Limit the intake of alcoholic beverages. 7, limit the intake of pickled, smoked, and nitrite-containing foods. Among them, life should pay attention to food diversity, plant-based food should account for more than 2/3 of each meal, plant-based diet should contain fresh vegetables, fruits, legumes and coarse grains, etc. A balanced diet is an important means of preventing a variety of diseases.