musculoskeletal system disorder sarcoma synovial chondromatosis https://rarediseases.info.nih.gov/diseases/6054/synovial-chondromatosis Synovial chondromatosis is a type of non-cancerous tumor that arises in the lining of a joint. The knee is most commonly affected, however it can affect any joint. The tumors begin as small nodules of cartilage. These nodules can separate and become loose within the joint. Some tumors may be no larger than a grain of rice. Synovial chondromatosis most commonly occurs in adults ages 20 to 50. Signs and symptoms may include pain, swelling, a decreased range of motion, and locking of the joint. The exact underlying cause of the condition is unknown. Treatment may involve surgery to remove the tumor. Recurrence of the condition is common. UMLS:C0008476 Reichel's syndrome MONDO:0006438 MESH:D015838 synovial osteochondromatosis EFO:1000557 NCIT:C34467 MEDGEN:40275 Henderson-Jones syndrome connective and soft tissue neoplasm