畸胎瘤绝大多数发生于纵隔内，亦可发生于卵巢、后腹膜腔或其他部位，但发生于后腹膜腔者相对少见。现将我院经手术病理证实左侧腹膜后囊性畸胎瘤1例报告如下。病例女，27岁。半年前偶然发现左上腹有一拳头大包块，逐渐增大，时有隐痛，无恶心呕吐、便血，无发热盗汗。近1个月? The vast majority of teratomas occur in the mediastinum, but also in the ovary, retroperitoneal cavity or other sites, but relatively rare in the posterior peritoneal cavity. A case of left retroperitoneal cystic teratoma confirmed by surgical pathology in our hospital is reported below. Female case, 27 years old. Six months ago, he accidentally discovered that there was a fist mass on the left upper abdomen, which gradually increased. There was pain, no nausea, vomiting, blood in the stool, and no fever and night sweats. Nearly 1 month?