Fig. 2

(a) A girl aged 10 years at the first presentation. Lateral radiographs of the right proximal tibia showing a typical NOF in stage B: distant from the epiphysis, polycyclic shaped and with clearly sclerotic borders. The cortex is protruding like the shape of an hourglass. (b) Three years later typical ossification beginning at the diaphysis is evident, representing a stage C lesion. (c) Complete homogeneous sclerosis of the lesion at the patient age of 17 years