1病例介绍患者女,55岁。1年前发现左膝关节髌骨下“桃核”样大小肿物突出于皮肤表面,无痛,未行系统治疗;后无明显诱因肿物逐渐增大,左膝关节屈伸活动受限,于2014年3月12日入院。检查:左膝关节髌骨下方皮肤隆起明显,无红肿及静脉怒张;局部可触及一大小约8.0 cm×5.0 cm×3.0 cm肿物,质硬,无压痛及叩击痛,肿物与周围组织分界不清,活动度差;膝关节被动活动度为20~80°;左下肢远 1 case description Female patient, 55 years old. A year ago found that the left knee joint patella “peach” like size of the tumor prominent on the skin surface, painless, no systematic treatment; no obvious cause of tumor gradually increased, left knee flexion and extension activities limited, Admitted to hospital on March 12, 2014. Check: the left knee below the patellar skin uplift obvious, no swelling and venous rash; local touches a size of about 8.0 cm × 5.0 cm × 3.0 cm mass, hard, no tenderness and percussion pain, the tumor and surrounding tissue Unclear boundaries, poor activity; knee passive motion of 20 ~ 80 °; left lower limb