PDF(Pubmed)
Abstract：
Fetus in fetu (FIF) is a rare anomaly of diamniotic monochorionic twins, where a malformed fetus resides within the body of its twin. Most FIF occurs in the retroperitoneal region around the host spine and appears prenatally as a solid-cystic mass consisting of fetal-like structures. Imaging has an important role in the diagnosis of FIF. The present study reported a single case, a 45-year-old woman, with a teratoma in a third-trimester fetus diagnosed after prenatal ultrasonography (US), which showed a mass containing fetus-like echoes. FIF was considered after the US showed that the mixed solid-cystic retroperitoneal mass around the vertebral axis of the host fetus consisted of two separate masses, each containing distinct fetal visceral structures. One fetus was acardiac and the other parasitic fetus was visible with a weak heartbeat. Postpartum magnetic resonance imaging and ultrasonography (US) scans of the newborn showed a retroperitoneal cystic space-occupying mass with distinctive limbs and visceral structures. The pathological examination further confirmed the diagnosis of retroperitoneal FIF. Also, a prenatal US could detect FIF in utero. A cystic-solid mass containing long bones, vascular pedicles, or visceral structures around the vertebral axis of the host fetus in the US might suggest the possibility of a FIF.
摘要：
胎儿（FIF）是羊膜单绒毛膜双胞胎的罕见异常，畸形的胎儿位于其双胞胎体内。大多数FIF发生在宿主脊柱周围的腹膜后区域，并在产前表现为由胎儿样结构组成的实性囊性肿块。影像学在FIF诊断中具有重要作用。本研究报告了一个病例，一个45岁的女人,产前超声检查（US）后诊断为妊娠晚期胎儿畸胎瘤，显示出一个含有胎儿般的回声的肿块。在US显示宿主胎儿椎骨轴周围的混合实囊性腹膜后肿块由两个单独的肿块组成后，考虑了FIF。每个包含不同的胎儿内脏结构。一个胎儿是无心胎儿，另一个寄生胎儿可见，心跳微弱。新生儿的产后磁共振成像和超声检查（US）扫描显示腹膜后囊性占位性肿块，具有独特的四肢和内脏结构。病理检查进一步证实了腹膜后FIF的诊断。此外，产前美国可以在子宫内检测到FIF。包含长骨的囊实性肿块，血管蒂,在美国，宿主胎儿椎体周围的内脏结构或内脏结构可能提示FIF的可能性。
