患者男,13岁。双下肢皮肤出现多发性水泡状结节多年并逐渐增多(图1),1个月前双下肢开始出现疼痛不适。双膝关节X线检查:双侧股骨与胫骨多发性斑片状或类圆形低密度,边缘不清(图2)。双膝关节CT检查:双侧股骨与胫骨、腓骨见多发性大小不一类圆形与斑片状低密度,边缘清晰,密 Patient male, 13 years old. Double lower extremity skin appear multiple blisters nodules for many years and gradually increased (Figure 1), a month ago began to appear in both lower extremity pain discomfort. Double knee X-ray examination: bilateral femur and tibia multiple patchy or nearly circular low-density, margin unclear (Figure 2). Double knee CT examination: both sides of the femur and tibia, fibula see multiple sizes are not uniform round and patchy low density, clear edges, dense