A patient with breast cancer metastasis to the bones presents with thigh pain and focal tenderness over the midshaft of the femur. Which fracture type should be suspected?

• A. Compound fracture
• B. Pathologic fracture
• C. Greenstick fracture
• D. Comminuted fracture

Answer: (B)

When bone is invaded by cancer, it loses structural strength. A fracture can then occur with little or no trauma, because the bone is weakened by the tumor. That’s a pathologic fracture. In this scenario, a patient with breast cancer that has metastasized to bone who has thigh pain and focal tenderness over the femur strongly suggests a fracture through bone that's been weakened by metastasis, rather than a simple break from normal wear or a high-energy injury.

A compound fracture would involve an open wound communicating with the fracture, which isn’t described here. A Greenstick fracture is an incomplete break typical of children with softer bones. A comminuted fracture involves many fragments and usually results from high-energy trauma. The clue tying this situation to a pathologic fracture is the known bone metastasis causing weakness in the femur.