Chen C P, Chern S R, Liu F F, Jan S W, Lee H C, Sheu J C, Lee W T, Wang T Y
Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China.
Prenat Diagn. 1997 Jan;17(1):13-21.
We report the prenatal diagnosis, pathology, cytogenetics, and molecular studies of a retroperitoneal fetus in fetu. Prenatal ultrasonography of the host fetus in the third trimester showed an anencephalic, acardiac mass with identifiable extremities and spine within an intra-abdominal cystic mass. Pathological examination revealed a fetiform mass weighing 20 g with four extremities, digits, vertebral bodies, an oral cavity with developing teeth, primitive male external genitalia, a urinary bladder, a cloaca with an external opening, large intestines, a membranous capsule, and an umbilical cord with one artery, one vein, and Wharton's jelly. Histological examination demonstrated nerve bundles in the fibrocollagenous tissue below the cuboidal surface epithelium of the membranous capsule, and absence of lamina elastica interna and vasa vasorum in the single artery of the umbilical cord. Both the host infant and the fetus in fetu had a normal 46,XY karyotype. Molecular analysis using informative genetic markers showed no genetic difference between the host infant and the fetiform mass. We report this case as an unusual example of fetus in fetu in co-existence with an amnion-like membrane containing nerve bundles and with a well-formed umbilical cord. We demonstrate that fetus in fetu can be diagnosed prenatally if the fetiform mass has well-developed limbs and spine. We emphasize the necessity for suspicion of fetus in fetu when a well-defined encapsulated cystic mass with calcified solid components is detected prenatally in a fetus by ultrasonography.
我们报告了1例腹膜后胎内胎的产前诊断、病理学、细胞遗传学及分子研究情况。孕晚期宿主胎儿的产前超声检查显示，在腹腔内囊性肿物内有一个无脑、无心的肿物，可见明显的四肢和脊柱。病理检查发现一个重20 g的胎儿样肿物，有四肢、手指、椎体、有正在发育牙齿的口腔、原始男性外生殖器、膀胱、有外口的泄殖腔、大肠、膜性包膜以及一条有一条动脉、一条静脉和华通胶的脐带。组织学检查显示，膜性包膜立方体表皮下的纤维胶原组织中有神经束，脐带单条动脉中无内弹性膜和血管滋养管。宿主婴儿和胎内胎的核型均为正常的46,XY。使用信息性遗传标记进行的分子分析显示，宿主婴儿与胎儿样肿物之间无遗传差异。我们将此病例报告为胎内胎的一个不寻常例子，其与含有神经束的羊膜样膜和发育良好的脐带并存。我们证明，如果胎儿样肿物有发育良好的肢体和脊柱，胎内胎可在产前诊断。我们强调，当产前超声检查在胎儿中发现一个边界清晰且有钙化实性成分的包膜性囊性肿物时，怀疑胎内胎的必要性。
