Bilateral multiple malignant transformation of Ollier's disease.

We treated a 26-year-old man with a 19-year history of Ollier's disease. Secondary chondrosarcomas developed metachronously at four separate locations: both femora, left proximal tibia and fibular head. All four lesions were surgically excised, and each specimen was histologically identified as grade 1 or 2 chondrosarcoma. Clinical follow-up for 20 years beginning at the time of first tumor surgery has shown no evidence of local recurrence or metastasis. This is the first report of multiple bilateral metachronous malignant transformation of multiple chondromatoses in a patient with Ollier's disease.