This patient has a sclerotic, well-defined lesion of the distal left tibia. The lesion seems to also have some lucent component. It is a bit hard to tell just where in the tibia this lesion is on an AP film alone. A lateral film would have shown that this lesion was located adjacent to the anterolateral cortex of the tibia. After seeing the plain film, most musculoskeletal radiologists would have felt comfortable stopping the workup at this point, feeling strongly that this lesion was diagnostic for a certain benign process. However, this patient was seen by someone a bit less comfortable with that diagnosis, and was referred for a CT exam. Several representative CT slices are shown below.
