Giant Cell Tumor of Distal End Femur: a Challenge in Treatment

INTRODUCTION Giant cell tumor of the bone is a relatively uncommon tumor. It is characterized by the presence of multinucleated giant cells. The tumor is usually regarded as benign. In most patients, giant cell tumors have an indolent course, but tumors recur locally in as many as 50% of cases. Metastasis to the lungs may occur. Cooper first reported giant cell tumors in the 18th century. In 1940, Jaffe and Lichtenstein defined giant cell tumor more strictly to distinguish it from other tumors. Giant cell tumor usually occurs de novo but also may occur as a rare complication of Paget disease of the bone. Giant cell tumor of the bone accounts for 4-5% of primary bone tumors and 18.2% of benign bone tumors. The incidence is increased in patients with Paget disease of the bone, in which giant cell tumor is a rare neoplastic complication. Giant cell tumor is a rare complication compared with Paget sarcoma, which has an incidence of sarcomatous change of <5%. A slight female predominance is noted; approximately 50-57% of cases involve female patients. Typically, giant cell tumors occur in skeletally mature patients aged 20-40 years. The incidence peaks in those aged 20-30 years. Giant cell tumors are much less common in children; the rate is 5.7% in skeletally immature patients. Vertebral tumors tend to occur in younger patients; 29% of these tumors occur in those aged 0-20 years. Multicentric giant cell tumors also occur in a younger group, with a peak incidence in those aged 10-20 years. Multicentric tumors involve less than 1% of patients.