RT Journal A1 Crawford, Eileen A. A1 Brooks, John S.J. A1 Ogilvie, Christian M. T1 Osteosarcoma of the Proximal Part of the Radius in Mazabraud SyndromeA Case Report JF The Journal of Bone & Joint Surgery JO The Journal of Bone & Joint Surgery YR 2009 FD April 1 VO 91 IS 4 SP 955 OP 960 DO 10.2106/JBJS.H.00212 UL http://dx.doi.org/10.2106/JBJS.H.00212 AB Malignant transformation of fibrous dysplasia into sarcoma is a rare event, occurring in less than 1% of cases1,2. Malignant transformation of fibrous dysplasia can also occur as part of Mazabraud syndrome, a syndrome characterized by fibrous dysplasia and intramuscular myxomas1. However, Mazabraud syndrome is so rare that only four cases of sarcomatous degeneration have been reported in the literature1,3-5. Here we report a fifth case, which involved the development of osteosarcoma in a fibrous dysplastic lesion of the proximal part of the radius in a patient with Mazabraud syndrome.