What is giant cell tumor?

➢ Almost exclusively affects adults ➢ Locally aggressive neoplasm ➢ Arise in the epiphyses of long bones, most commonly the distal femur and proximal tibia. ➢ lytique eccentric tumor with deformation of the contours of the bone. ➢ Limited by a thin bony shell (no real soft tissue infiltration). ➢ Sometimes lung implants considered “benign” ➢ Microscopically, the tumor conspicuously lacks bone or cartilage, consisting of numerous osteoclast-type giant cells with 100 or more nuclei with uniform, oval mononuclear tumor cells in between.