Giant Cell Tumor of Bone

Description: AAOS Fact sheet Giant cell tumor of bone (GCT) is a rare, aggressive non-cancerous (benign) tumor. It generally occurs in adults aged 20 to 40. GCT is very rarely seen in children or in adults over age 65. Giant cell tumors are named for the way they look under the microscope-many "giant cells" are seen. They are formed by fusion of several individual cells into a single, larger complex. Many bone tumors and other conditions (including normal bone) contain giant cells; GCT is given its characteristic appearance by the constant finding of a large number of these cells existing in a typical background. Most bone tumors occur in the flared portion near the ends of long bone (metaphysis), but GCT occurs almost exclusively in the end portion of long bones next to the joints (epiphysis). In rare cases, this tumor may spread to the lungs. Robert Quinn, MD (n) Author Associate Professor of Orthopedic Surgery & Director of Orthopedic Oncology, University of New Mexico School of Medicine J. Sybil Biermann, MD (*) Physician Reviewer Associate Professor, University of Michigan Department of Orthopaedics, Ann Arbor MI Nancy Fehr (*) Medical Editor Patient education specialist, American Academy of Orthopaedic Surgeons