A 15-year-old boy presents with persistent pain and swelling around his left knee. He reports worsening pain at night and difficulty walking. On examination, there is localized tenderness and a firm mass above the tibia. Radiographs reveal a sunburst pattern and Codman’s triangle at the metaphysis of the distal femur.

What is the most likely diagnosis?

A 50-year-old man presents with a slow-growing, painless swelling in his left pelvis. X-rays reveal a lobulated radiolucent mass with rings and arcs calcification. There is no history of trauma, and lab values are within normal limits.

Which of the following is the most likely diagnosis?

An 18-year-old male presents with a painless swelling on the distal femur noticed during a sports physical. What is the most likely diagnosis?

Which of the following is most characteristic of Achondroplasia

Which of the following best describe the origin of chondrosarcoma

Which of the following features most reliably distinguishes Ewing sarcoma from Osteomyelitis?

Which of the following features would help distinguish Osteosarcoma from Ewing sarcoma in a young patient?

Which of the following gene mutations leads to Achondroplasia

A 12-year-old boy presents with pain and swelling in the mid-shaft of his femur. He has had low-grade fever and weight loss. Physical examination reveals tenderness and warmth over the area. Radiograph shows onion-skin periosteal reaction.

What is the most likely diagnosis?

Which of the following radiographic feature is characteristic of Osteochondroma?