Body Stalk Anomaly: Analysis of 10 Autopsy Cases

Lee, Seung Sook; Chi, Je G

Abstract

Body stalk anomaly represents an extreme maldevelopment of embryonic body folding and is characterized by absence of the umbilicus and umbilical cord. The failure of complete obliteration of the extraembryonic coelom is responsible for the absence of the umbilical cord formation and the wide-based insertio of the amnioperitoneal membrane onto the placental chorionic plate. We have analyzed 10 autopsy cases of various midline anomalies of the body that could best be classified into body stalk anomaly. All cases were either stillborns or dead immediately after birth. The pregnancy was interrupted due to this anomaly in 6 cases, and their gestational ages varied from 17 weeks to 37 weeks. The affected fetuses were characterized bt absent or vestigial umbilical cord, and ruptured amnion with direct amnioperitoneal connection without the mediation of the umbilical cord. Exomphalos with abdominal wall defect and serve scoliosis were characteristic components of this anomaly, that provided important clues in differentiating other similar anomalies. Other associated anomalies included neural tube defect, intestinal atresia, genitourinary and skeletal defects, pulmonary hypoplasia, single umbilical artery and narrow-spaced chest and abdomen, etc. These findings strongly suggest that anomaly of body stalk represents mechanical teratogenesis due to early amnion repture and subsequent effect, and should be categorized into amniotic band disruption syndrome.