Osteosarcoma most commonly arises where in adolescents?

Osteosarcoma most commonly arises where in adolescents?

• A. Distal femur metaphysis
• B. Proximal humerus metaphysis
• C. Proximal tibia diaphysis
• D. Distal radius metaphysis

Answer: (A)

Osteosarcoma in teens tends to originate in the metaphysis of long bones, where bone growth is most active. The distal femur near the knee is the most common site because this region has the highest osteoblastic activity during the adolescent growth spurt, making malignant transformation of osteoblasts most likely there. That’s why the distal femur metaphysis is the best answer. The proximal humerus metaphysis is another frequent location, but not as common as the distal femur. Involvement of the proximal tibia is also seen, but a diaphyseal location is less typical for osteosarcoma and more typical for other tumors like Ewing sarcoma. The distal radius metaphysis is less commonly affected.

Osteosarcoma in teens tends to originate in the metaphysis of long bones, where bone growth is most active. The distal femur near the knee is the most common site because this region has the highest osteoblastic activity during the adolescent growth spurt, making malignant transformation of osteoblasts most likely there. That’s why the distal femur metaphysis is the best answer.

The proximal humerus metaphysis is another frequent location, but not as common as the distal femur. Involvement of the proximal tibia is also seen, but a diaphyseal location is less typical for osteosarcoma and more typical for other tumors like Ewing sarcoma. The distal radius metaphysis is less commonly affected.