Synovial Chondromatosis

Note the resemblance to Grade 1 chondrosarcoma. Synovial chondromatosis must be distinguished from osteocartilagenous loose bodies that are seen in the setting of degenerative joint disease or some other preexisting condition. Loose bodies lack the clustering of chondrocytes and nuclear atypia. Synovial chondromatosis involves joints diffusely and it often recurs, presumably from tumor nodules left behind from initial resection.