英译汉Giant cell tumor of bone (GCT) accounts for approximately 5-9% of primary bone tumors and 20% of benign bone tumors. GCT occurs only after the epiphyseal plates have closed. It most commonly presents in patients between the ages of 25 and 40 and has a slight female predominance. GCT can arise in any bone of the skeleton, but is most frequently detected around the knee (50%); it involves the epiphyseal regions of the distal femur and proximal tibia, although it originates in the metaphysis. GCT is a locally aggressive, generally benign lesion; however, 10% are malignant with local spread or metastases, generally to the lungs. The tumor is usually subcortical and related to the fused growth plate of a metaphysis. It thins the cortex, and periosteal reaction is rare in the absence of a pathological fracture. Soft tissue extention may occur in as many as 50% of cases, sometimes crossing the joint via an extracapsular route. Some conditions such as aneurysmal bone cyst, chondroblastoma, and osteosarcoma may resemble GCT on plain-film radiographs and should be considered in the differential diagnosis.