We treated a patient with large multiple chondrosarcomas derived from
multiple cartilaginous exostoses, One sarcoma originated in the left p
ubic bone and the other sarcoma in the posterior aspect of the greater
trochanter of the left femur. Thirty months after hindquarter amputat
ion, the patient is alive without relapse. This is the first report of
a patient with synchronous multiple malignant transformation of multi
ple cartilaginous exostoses.