探讨胎盘间叶发育不良的超声声像图特征及鉴别诊断要点。

分析2013年1月至2017年12月在首都医科大学附属北京妇产医院超声检查并经手术及病理证实为胎盘间叶发育不良患者的超声声像图特征，总结胎盘间叶发育不良超声诊断及鉴别诊断要点。

6例胎盘间叶发育不良在不同妊娠阶段表现为不同的超声特征：妊娠12周前后胎盘非均质弥漫性增厚，胎盘实质内出现微小囊性病变，直径小于1 mm；至妊娠22周前后囊性病变扩张最显著，主要超声特征是胎盘子面局部蜂窝状低回声区，与正常胎盘组织分界清晰，病变区内大小不等的囊性回声多数呈长圆形，平行于胎盘长轴分布；随后病变区囊性改变逐渐缩减，至妊娠28周前后病变区逐渐缩至与妊娠12周前后相似状态，但与周边正常胎盘组织分界清晰，部分病例出现脐静脉迂曲扩张等表现。1例合并Beckwith-Wiedemann综合征，胎儿脐膨出。

胎盘间叶发育不良有特征性的超声表现及规律的疾病演变过程。胎盘间叶发育不良与葡萄胎的预后不同，因此二者的鉴别诊断非常重要，超声在胎盘间叶发育不良的早期诊断中具有重要价值。

To explore the sonographic features, diagnosis, differential diagnosis and prognosis of placental mesenchymal dysplasia (PMD). Because ofthe lack of knowledge about the ultrasonic patterns of this kind of disease, misdiagnosis frequently happens. Throughreviewing the cases and relevant researches, we are able to understand the disease and figure it out inultrasonic images.

Six cases of patients with Placental mesenchymal dysplasia were reviewed which werehospitalized in Beijing Obstetrics and Gynecology Hospital during 2013 to 2017. All of the patients underwentultrasound examinations before surgery. And the diagnosisof placental mesenchymal dysplasia was confirmed by placental pathology. Inclusion criteria for the review were diagnosis of PMD as defined by placental pathology, description of placental morphology on antenatal ultrasound and reporting of pregnancy outcomes.

All of 6 patients were found abnormal ultrasound results at routine examination of the pregnancy. The placentas were enlarged, partly with mini cysts at 12 weeks. The sonographic featurewas peak at 22 weeks, the local hive hypoechoic region of the placenta subsurface had clear border with normal placental tissue. Most of the cystic echoes of different size in the area were long circular, parallel to the distribution of the long axis of the placenta, and then the cystic change of the lesion gradually reduced, and the lesion area gradually returned to the similar state as 12 weeks of pregnancy, but it had clear border with the surrounding normal placental tissue at the 28 week of pregnancy. Some patients had umbilical vein dilation. One case PMD and fetal omphalocele suggestive of Beckwith-Wiedemann syndrome.

When a cystic placenta is detected by ultrasound examination, placental mesenchymal dysplasia should be considered in the differential diagnosis. PMD must be differentiated from gestational trophoblastic disease because management and outcomes differ.