Which type of bone cancer is typically located in the distal femur?

Osteosarcoma is a malignant bone tumor that most commonly occurs in the metaphysis of long bones, especially around the knee, making the distal femur a typical location. This form of bone cancer is highly aggressive and tends to occur in adolescents and young adults during periods of rapid skeletal growth. The tumors are characterized by the production of osteoid, which is the bone matrix produced by osteoblasts, and they can present with pain, swelling, and sometimes pathological fractures.

While Ewing's sarcoma typically arises in the diaphysis of long bones and may also present in the pelvis and chest wall, and giant cell tumors usually occur around the knee but are more common in the proximal tibia, they are less frequently identified specifically in the distal femur compared to osteosarcoma. Chondrosarcoma, a malignancy of cartilage, tends to occur in older individuals and is typically found in the metaphyseal or diaphyseal regions of long bones, further differentiating its commonality from that of osteosarcoma in the specified location.

Given these details, osteosarcoma's predilection for the distal femur makes it the most accurate choice in this context.