图示骨肉瘤，股骨骺端出现了一大半轮状肿块。多见于年轻人（可见右侧明显的骨骺）。

骨肉瘤：股骨(肉眼) 胫骨(肉眼) 股骨远端X线 低倍镜 高倍镜

This femur has a large eccentric tumor mass arising in the metaphyseal region. This is an osteosarcoma (a variant known as parosteal osteogenic sarcoma) of bone. These tumors most often occur in young persons (note that the epiphysis seen at the right is still present).