bone, joint, and muscle disorders
Noncancerous Bone Tumors
Enchondromas
Enchondromas may occur at any age but tend to develop in people aged 10 to 40 years. These tumors develop in the central part of a bone (the marrow cavity) in long bones. These tumors usually do not cause symptoms, but some may grow larger and cause pain. The tumors often are discovered when x-rays are taken for other reasons, and doctors often can diagnose them by their appearance on the x-ray. If the tumor cannot be identified with certainty on x-rays or if it causes pain, removal of a tissue sample for examination under a microscope ( Diagnosis ) may be needed to confirm the diagnosis of enchondroma and rule out the possibility of a cancerous tumor. If an enchondroma does not cause pain and if repeated x-rays show no enlargement, it does not have to be removed or treated. Enchondromas may change into a cancerous (malignant) bone tumor called a Chondrosarcomas . This change is rare in people who have only a single enchondroma, but in people who have multiple enchondromas (called enchondromatosis), the change to a cancerous tumor is more common. Follow-up x-rays may be taken to monitor any changes in size and make sure the tumor has not become a chondrosarcoma. 