【双语摘要】|| 胎儿卵巢囊肿的影像学诊断与鉴别诊断

Fetal Ovarian Cysts: Review of Imaging Spectrum, Differential Diagnosis, Management, and Outcome

Fetal ovarian cysts are the most common abdominal cysts observed in the female fetus but may be mistaken for genitourinary cysts, gastrointestinal cysts, lymphangiomas, or fetus in fetu. Ultrasonography (US) is the imaging modality of choice for fetal assessment, and magnetic resonance imaging is a useful problem-solving tool when uncertainty remains after careful US evaluation. At US, a fetal ovarian cyst manifests as an anechoic thin-walled cyst superior and parasagittal to the bladder. A daughter cyst may occasionally be observed and is pathognomonic for a cyst of ovarian origin. Fetal ovarian cysts may be simple or complicated and unilateral or bilateral, and they may masquerade as a solid mass when hemorrhage or torsion occurs.  Complicated cysts may exhibit multiple septations, fluid-fluid levels, or mobile internal echoes. It is important to differentiate a hemorrhagic ovarian cyst from solid abdominal neoplasms that may be seen in a fetus. Recognition of the pertinent imaging findings will help radiologists distinguish fetal ovarian cysts from other fetal intra-abdominal masses in the differential diagnosis. Malignant ovarian neoplasms are rare in the fetus and neonate and thus are not considered in the differential diagnosis. The current literature on the management and outcome of fetal ovarian cysts is reviewed, with imaging studies presented from the authors’ practice. Most fetal ovarian cysts resolve spontaneously; if operative intervention is required, the goal should be ovarian preservation.

胎儿卵巢囊肿：成像序列、鉴别诊断、治疗和结局综述

摘要：胎儿卵巢囊肿是女胎中最常见的腹部囊肿，但是可能被误诊为生殖泌尿系囊肿、胃肠道囊肿、淋巴管瘤或者寄生胎。超声是一项评估胎儿的成像方式，当超声仔细评估后仍然不能确定时，MRI是有用的解决问题的工具。在超声检查中，胎儿卵巢囊肿表现为膀胱上方旁矢状面的无回声薄壁囊肿。偶尔可发现子囊，这是卵巢源性囊肿的特有表现。胎儿卵巢囊肿可以是单纯的或复杂的、单侧或双侧的，当出现出血或扭转时可表现为实性包块。复杂性囊肿可能表现为多个分隔、液液平面或者内部可移动的高回声影。将出血性卵巢囊肿与胎儿可能发生的腹部实性肿瘤相鉴别是及其重要的。对相关影像表现的认识可帮助影像医生将胎儿卵巢囊肿与其他胎儿腹内包块进行鉴别。恶性卵巢肿瘤在胎儿和新生儿中很罕见，所以在鉴别诊断中不予考虑。回顾目前关于胎儿卵巢囊肿处理和结局的文献，大部分胎儿卵巢囊肿可自行消失；如需进行手术干预，那么手术目标是卵巢保护。

TEACHING POINTS

· Fetal ovarian cysts generally manifest in the third trimester and are thought to be a consequence of exposure to elevated hormonal levels.

· Simple ovarian cysts are round, anechoic, unilocular, and thin walled.

· The “daughter cyst” sign describes a small, round, anechoic structure within a cyst. It is reported to be pathognomonic for ovarian cysts.

· At US, complicated or complex ovarian cysts are thick walled, with heterogeneous echogenicity. The imaging features include multiple septations, mobile internal echoes, a solid appearance, or a fluid-fluid level.

· The most conservative postpartum approach to management of ovarian cysts is a period of observation because many cysts will regress spontaneously.

教学点：

l 胎儿卵巢囊肿通常出现于晚孕期，被认为是胎儿暴露于过高激素水平的结果。

l 单纯性卵巢囊肿是圆的、无回声的、单房的和薄壁的。

l “子囊征”用来描述囊内小的、圆形无回声结构。被认为是卵巢囊肿的特有征象。

l 在超声检查中，复杂性卵巢囊肿是厚壁的，并伴有不均质回声。图像特征包括多个分隔、内部的可移动回声、实性病变或液液平面。

l 胎儿卵巢囊肿最常见的生后保守治疗方法是期待疗法，因为很多囊肿会自行消退。