Codman's triangle is a feature of -
A Codman triangle develops when a poion of periosteum is lifted off of the coex by tumor, pus, or hemorrhage at a leading edge . This aggressive form of periosteal reaction is commonly seen in osteosarcomas and occasionally with infection and metastases.
Osteosarcoma
Osteochondroma
Osteoid osteoma
Chondrosarcoma
Skeletal system