Harris C P, Townsend J J, Norman M G, White V A, Viskochil D H, Pysher T J, Klatt E C
Department of Pathology, University of Utah, Salt Lake City.
J Child Neurol. 1994 Oct;9(4):412-6. doi: 10.1177/088307389400900416.
Absence of the telencephalon and diencephalon characterizes the syndrome of aprosencephaly, while in atelencephaly, only the telencephalon is absent. Atelencephalic aprosencephaly is characterized by the presence of at least a rudimentary diencephalon. Embryologically, aprosencephaly is thought to occur after the optic vesicles form but before the cerebral vesicles appear. The syndrome is quite rare, with only 10 cases previously reported. We describe two fetuses with atelencephalic aprosencephaly. A 25-week estimated gestational age fetus was born to first-cousin parents and had a prenatal ultrasonographic diagnosis of anencephaly. The second, a 19-week estimated gestational age fetus, was thought to have semilobar holoprosencephaly by prenatal ultrasound. At autopsy, neuropathologic examination in both cases showed virtual absence of the cerebral hemispheres with an incomplete diencephalon. Microscopic examination in one case revealed disorganized neuropil with a proliferative vasculopathy. The optic globes were completely formed and attached to hypoplastic optic nerves, but retinal dysplasia was apparent histologically in both cases, and bilateral colobomata were present in one case. The findings in these cases demonstrate a spectrum of congenital variations that lie between the syndromes of atelencephaly and aprosencephaly, underscoring the complexity of the congenital anomalies.
无脑回畸形综合征的特征是端脑和间脑缺失，而在无端脑畸形中，仅端脑缺失。无端脑无脑回畸形的特征是至少存在一个发育不全的间脑。从胚胎学角度来看，无脑回畸形被认为发生在视泡形成之后但大脑泡出现之前。该综合征非常罕见，此前仅报道过10例。我们描述了两例无端脑无脑回畸形的胎儿。一名孕周估计为25周的胎儿由近亲父母所生，产前超声诊断为无脑儿。第二例，孕周估计为19周的胎儿，产前超声检查认为患有半侧脑叶型前脑无裂畸形。尸检时，两例的神经病理学检查均显示大脑半球几乎完全缺失，间脑不完整。其中一例的显微镜检查显示神经纤维排列紊乱并伴有增生性血管病变。眼球完全形成并附着于发育不全的视神经，但两例组织学上均明显可见视网膜发育异常，其中一例存在双侧脉络膜缺损。这些病例的发现表明了一系列介于无端脑畸形和无脑回畸形综合征之间的先天性变异，突显了先天性异常的复杂性。
