Enchondromatosis, or multiple enchondromas, refers to a group of disorders of which Ollier disease is the best known. This is nonhereditary disorder which usually presents in childhood. Nominally, the disease consists of multiple enchondromas. However, on radiographs, streaks of low density are seen projecting through the diaphyses into the epiphyses of the long bones, due to ectopic cartilage deposits. With age, the cartilage may calcify in the typical "snowflake" pattern. The affected extremity is shortened (asymmetric dwarfism) and sometimes bowed due to epiphyseal fusion anomalies.
Patients are at risk for development of sarcomas, specifically osteosarcomas and chondrosarcomas. These occur in approximately 25 % of patients.
Mafucci syndrome represents enchondromatosis with oft tissue hemangiomas, usually in the hands and feet. As with Ollier disease, there is typically a shortening of the long bones. These patients are at higher risk for sarcomatous transformation of both the vascular and cartilaginous portions of the disease.
