Fig. 5A–C.

(A) A lateral radiograph shows an area of ill-defined lucency (black arrow) in the distal femur with adjacent soft tissue density (black arrowheads). An area of bone infarct is seen in the proximal tibia (white arrow). (B) A sagittal T2-weighted fat saturation MR image shows the area of bone infarct (black arrows) in the distal femur with an adjacent soft tissue density (black arrowheads). The bone infarct is seen in the proximal tibia (white arrow). (C) A sagittal gross section shows the mass in the distal femur arising from a bone infarct (black arrows). The soft tissue mass is seen anteriorly (black arrowheads).