Osteochondroma of the knee.

This article discusses a case of osteochondroma suffered by a female patient. The typical clinical and radiographic signs and symptoms are presented. Osteochondromas may be pedunculated or sessile. Malignant transformation ranges from 1% for solitary lesions to 20% for hereditary multiple exostoses. If transformation occurs, chondrosarcoma usually develops. Most lesions are asymptomatic and require no treatment.