GCT of bone is a lesion with unpredictable behaviour. It presents as a lytic defect in the end of long bone, most frequently affecting the knee area. Although benign, it is locally aggressive and deserves specific treatments that result in decreased local recurrence and preservation of function. Extended curettage followed by cementing or bone grafting of some kind is the most often used treatment. En bloc resection is rarely a necessity and is used for more aggressive lesions when the bone or joint surface cannot be salvaged. With modern staging and treatment, the overall local recurrence rate is between 10% to 20%. Local recurrences are usually treated in same manner as primary tumors. Lung metastases from benign GCT of bone exists and should be treated vigorously. Malignancy is rarely associated with GCT but may be found in a recurrent tumor or years after irradiation of a previously benign GCT. Malignant tumors should be managed in the same manner as sarcomas.
