To make the diagnosis of Ollier disease, the bone should be dysplastic. Patients may have multiple enchondromas with normal-appearing bones and, hence, they do not have Ollier disease.
Ollier disease is a rare syndrome. Historically, we are taught that approximately 30% of patients with Ollier disease will develop a chondrosarcoma. These are usually very low-grade lesions. If the patient has associated soft tissue angiomas, then the patient has Maffucci syndrome. The risk of chondrosarcoma in Maffucci syndrome may be as high as 100%. Again, these are low-grade chondrosarcomas. The patient is more typically to die from a high-grade visceral carcinoma, such as an astrocytoma, pancreatic tumor, liver tumor, or breast cancer.