Presentation
Pain and swelling left mid thigh after minor trauma.
Patient Data
Displaced fracture of the mid-shaft of the femur. A well-defined non-aggressive radiolucent lesion is seen in femoral shaft through which the fracture has occurred.
Displaced oblique fracture of the left femoral diaphysis. A well-defined radiolucent lesion with narrow zone of transition and thin peripheral sclerotic margins is seen in the central femoral diaphysis at the site of fracture. High density contents, likely representing hemorrhage secondary to the fracture, are seen within it. No periosteal reaction or soft tissue abnormality is seen.
Status post open reduction and internal fixation of the femoral shaft fracture (history of lesion curettage followed by a bone graft). Fracture fragments are well aligned. Post-surgical changes in the soft tissues of the thigh.
Histopathology of the contents removed from the femoral shaft lesion show simple bone cyst.
Case Discussion
Imaging features are suggestive of a non-aggressive radiolucent lesion, like a unicameral bone cyst/simple bone cyst, with a pathological fracture. The underlying osseous lesion was overlooked on the x-ray initially and a CT scan was performed for its confirmation on the clinician's request as the history (minor trauma) was not matching with the imaging findings of a displaced fracture.