Giant cell tumor of bone is one of the common primary bone tumors of unknown origin, probably starting in the mesenchymal tissue within the bone marrow. Giant cell tumors of bone are highly aggressive and have a high lytic destructive effect on bone. Very rarely, they have a tendency for reactive new osteogenesis and self-healing, and can cross the bone cortex to form soft tissue masses, with a high recurrence rate after curettage. Giant cell tumor of bone is a low-grade malignant or potentially malignant tumor. The disease tends to develop between the ages of 20 and 50, and is higher in women than in men. The primary site of giant cell tumor of bone is mostly in the epiphysis and gradually invades the epiphysis as the lesion expands. Giant cell tumors of bone mostly invade long bones, with the lower femur and upper tibia being the most frequent. The main clinical manifestations of giant cell tumor of bone are soreness or dull pain, occasionally severe pain, and nocturnal pain in larger lesions, which are the main reasons for patients to seek medical attention. Some patients have local swelling, which may be associated with bony swelling. When the lesion penetrates the bone cortex and invades the soft tissue, a local mass is evident. Patients often have pressure pain and increased skin temperature, and increased skin temperature is one of the bases for determining postoperative recurrence. In the active stage, the tumor is rich in blood flow, and angiography shows a diffuse vascular network into the tumor, resembling the image of a malignant mass. The movement of the joints adjacent to the lesion is restricted. The occurrence of tumor in trunk bone may produce corresponding symptoms, such as presacral mass may compress the sacral plexus nerve, causing severe pain, and compression of rectum causing difficulty in defecation. The main points of diagnosis of giant cell tumor of bone are: 1. Clinically, there is joint pain, swelling, pain and dysfunction when the tumor approaches the joint cavity. 2.X-ray shows that the lesion is located in the epiphysis, showing eccentric, osteolytic and swelling bone destruction with clear boundary, sometimes with soap bubble-like changes and mostly with obvious encapsulation. Pathological examination reveals that the tumor consists of dense, uniformly sized mononuclear cells, with a large number of multinucleated giant cells distributed in each department, and spindle fibroblast-like and round histiocyte-like cells distributed in the stroma. Treatment Treatment of giant cell tumors is based on surgical resection, with excision and scraping plus inactivation, and implantation of autologous or allogeneic cancellous bone or bone cement. The disease has a high recurrence rate, and for recurrence, resection or segmental resection or prosthetic implantation should be performed. In cases of G1-2T1-2M0, extensive or radical resection is appropriate. The disease is not effective against chemotherapy. For those who have difficulty in surgery (e.g. spine), radiotherapy is available, and sarcomatous transformation is likely to occur after radiotherapy. 1.Local excision After excision, giant cell tumor of bone can be completely excised if it has little effect on function, such as the upper end of fibula, lower end of ulna, upper end of radius, hand bone and foot bone. 2.Scraping plus adjuvant therapy This therapy can reduce the recurrence rate of tumor and preserve the function of the limb at the same time. Chemical method can apply phenol solution or anhydrous ethanol to apply the inner surface of the tumor cavity after scraping. Cytotoxic substances can be applied to the surface of local recurrence. Physical therapies are cryotherapy or heat treatment. When filling the cavity left by resection within the tumor with bone cement, the heat generated can prevent recurrence, i.e. the thermogenic reaction of bone cement causes local heat, which causes necrosis of the remaining tumor tissue without damaging normal tissue and avoiding complications. If the tumor is malignant, large in extent, with soft tissue infiltration or recurrence after surgery, local excision or amputation should be considered according to the specific situation. In some cases, after resection of the tumor, the joint loses its role (such as femoral neck), and artificial joint or joint fusion can be considered. 4.Radiotherapy For giant cell tumor of bone which is not easy to be operated by surgery or has excessive impact on function after resection (such as giant cell tumor of vertebral body), radiotherapy can be used and has certain efficacy. Malignant changes can occur after radiotherapy in a few patients. Patients who have undergone surgery or radiotherapy should be followed up for a long time to pay attention to any local recurrence, malignant changes and pulmonary metastasis.