• Age of patient
• Tumor density
• Sclerotic, lytic, mixed
• Well-circumscribed, poorly-marginated,septated
• Expansile or not
• Location
• Epiphyseal, diaphyseal, metaphyseal
• Pattern of destruction
• Geographic, moth-eaten, permeative
• Tumor matrix
• None, bony, cartilaginous
• Cortical destruction
• None, some, marked
• Periosteal reaction
• None, solid, lamellated, onion-skinning, Codman’s triangle
• Soft tissue extension