Low Grade Chondrosarcoma Presenting as Progressive Valgus Limb Deformity in a Growing Period

The peak incidence age of chondrosarcoma is late adulthood, and only few cases of chondrosarcoma have been reported in children and adolescents.[1][2][3][4] These tumors, when they occur in young people, often appear in unusual sites and may have a more ominous prognosis.2,4,5) It is subdivided into a variety of ways, including by histological grade, by whether it is primary or secondary, and by whether it is peripheral or central; among these, the single most prognostic sub-classification is the histological grade.Sometimes, the low grade chondrosarcoma is misdiagnosed as a benign cartilaginous bone tumor including enchondroma or periosteal chondroma at the time of preoperative biopsy.To decrease of false negative diagnosis of low grade chondrosarcoma, the clino-radiologic findings such as pain, endosteal scalloping and peritumoral edema are important as well as histologic demonstration.Progressive limb deformity can be a sign of bone tumor in growing children by influencing adjacent epiphyseal plate.We experienced the long meta-diaphyseal intramedullary bony lesion accompanying short intracortical separated lesion by trabecular bone of femur in a 15-year old man who was incidentally detected as a valgus deformity of the same side lower limb.The tumor may have caused premature closure of small lateral area at the distal femur physis and resulted in asymmetric growth of the distal femur.