骶管内囊性病变，尤其是硬膜外蛛网膜囊肿，其临床表现酷似椎间盘突出症，易造成误诊。我科收治１例，报告如下。患者男性，２５岁。因腰部被车撞伤后疼痛，左下肢后侧麻痛，咳嗽或打喷嚏时症状明显来诊。查体：Ｌ５～Ｓ１棘间压痛、叩击痛，并向左下肢放射，左侧直腿抬高... Internal cystic lesions of the fistula, especially epidural arachnoid cysts, are clinically similar to disc herniations and can be misdiagnosed. Our department received 1 case and the report is as follows. The patient is male, 25 years old. The pain was noticed after being hit by a car at the waist, and the back of the left lower extremity was numb. The symptoms were obvious when coughing or sneezing. Physical examination: L5 ~ S1 spinous tenderness, percussion pain, and radiation to the left lower extremity, left leg straight raise ...