Periosteal chondroma of the femur: A case report and review of the literature

Periosteal chondroma is a rare benign cartilage tumor located on the cortical bone, which may be mistaken clinically and histologically for other and more common tumors in this location. The current study reports the case of periosteal chondroma located in the distal femur of a 14-year-old female. A non-tender swelling, 5×4 cm in diameter, was identified on computed tomography, a radiological study of which revealed an overhanging edge and a radiolucent shadow with stippled calcification in radiographs and a lobular heterogeneous mass in magnetic resonance imaging. Cytological examination of the excision biopsy revealed cellular pleomorphism and binucleate cells. The patient underwent en bloc resection of the tumor and covering periosteum, and the histological diagnosis was subsequently determined to be periosteal chondroma. The present study also reviews nine previously reported cases of periosteal chondroma in the femur, with a discussion of the demographic characteristics, imaging features, differential diagnosis and treatment of bone tumors in this location. This study aims to inform clincians that periosteal chondromas may occur in the distal femur although osteochondromas are more common and to discuss making a differential diagnosis between periosteal chondroma and other bone tumors.