What congenital abnormality is characterized by abdominal contents coming through the umbilicus while remaining in the peritoneal sac?

The correct answer is omphalocele, which is a congenital defect where the abdominal contents, such as intestines, liver, or other organs, protrude through the umbilical area but are covered by a membranous sac. This is different from other congenital conditions, as the contents remain encased within the peritoneal sac, which provides a protective barrier.

Omphalocele occurs during fetal development when the abdominal wall does not completely close. It is essential to recognize that the sac containing the abdominal contents can be seen at birth, and surgery is typically required to repair the defect. This condition is often associated with other congenital abnormalities, which may complicate the clinical picture.

In contrast, intussusception involves a part of the intestine telescoping into itself and does not involve an abdominal wall defect. Gastroschisis is a condition where the abdominal contents are exposed outside the body without a protective sac. Hirschsprung's disease is characterized by a lack of nerve cells in the colon, leading to blockages, rather than an anatomical defect at the umbilical area. Understanding these distinctions clarifies why omphalocele is the correct identification for the given description.