What type of periosteal reaction that suggests aggression is present in this radiograph?
Codman triangle periosteal reaction
Radiography of the right knee shows a lesion in the posterior cortex of the distal femur associated with a mass in the adjacent popliteal fossa with fat blurring and a small posterior deviation of the fabella. The sign of the Codman triangle indicates an aggressive lesion, particularly when associated with the previous clinical history of a renal tumour.