Fig. 1

Initial X-ray findings of the right knee. Anteroposterior (a) and lateral (b) radiography of the right knee revealed multifocal osteolytic changes (arrow) in the distal metaphysis area of the right femur. There was a geographic lesion with an irregular margin, but, no sclerotic rim (Lodwick classification type 1B). There was no destruction of cortical bone. However, a subtle cortical thickening lesion suggesting solid type of periosteal reaction was found at superior aspect of lateral femoral condyle (arrow head, a)