Limb body wall complex: a critical review and a nosological proposal.

The analysis of the literature on limb body wall complex reveals a varied and rather confused spectrum of cases. However, we noticed the presence of at least 2 clearly distinguishable phenotypes. The first phenotype shows craniofacial defects and amniotic bands and/or adhesion; the second--without craniofacial defects--presents urogenital anomalies, anal atresia, and abdominal placental attachment, together with a persistence of the extra-embryonic coelom. We think these 2 phenotypes are the consequence of different pathogenetic mechanisms. The pathogenesis of the first type can be related to an early vascular disruption, while the pathogenesis of the second one is attributable to an intrinsic embryonal maldevelopment. Eight cases of the second phenotype were identified and the pathological findings proving this maldevelopmental origin are described.