Neoplastic changes occur in enchondromas. The average age for neoplastic change is 40 years of age. Vascular neoplasms have occurred in four reported cases, two hemangiosarcomas and two lymphangiosarcomas. Less than 100 cases have been reported in the United States. Bone and skin abnormalities cease by the second to third decade.
Patients have a good prognosis if no malignant degeneration occurs.
Patients usually have a normal life span. There is no increased frequency due to race. Maffucci syndrome appears to be sporadically inherited. There is no sex bias. Patients affected are usually short in stature and may have unequal arm or leg lengths due to the bone abnormalities.