滑膜骨软骨瘤病在临床上比较少见,但影像表现典型,一般诊断不难,但我们曾误诊1例,后经手术及病理证实,现报告如下。患者　男,3 8岁。主诉:外伤后,间断左膝痛1年。查体:髌骨下方可触及一骨性包块。X线示:左髌骨下缘稍外侧见一4cm×6cm圆形肿块影,肿块边界欠清晰,其内见斑片状钙 Synovial chondromatosis is relatively rare in clinical practice, but the typical image performance, the general diagnosis is not difficult, but we have misdiagnosed in 1 case, confirmed by surgery and pathology, are as follows. Patient male, 38 years old. Chief complaint: traumatic, intermittent left knee pain for 1 year. Physical examination: below the patella can reach a bone mass. X-ray showed: the left margin of the left patella slightly see a 4cm × 6cm round mass, the tumor boundary is not clear, see the patchy calcium