Abstract
A baby girl delivered at the gestational age of 38 week's was referred to our department because of an intraabdominal cyst diagnosed prenatally. There were no specific symptoms after birth. USG revealed a cyst-like structure with gut signature, and CT showed a cystic mass in the abdomen containing air. A preoperative diagnosis of duplication of the alimentary tract or Meckel's diverticulum was made, and a laparoendoscopic single-site surgery was performed when the baby girl was ten months old. An inverted Y-shaped incision was made at the umbilicus, and laparoscopic exploration revealed a cystic mass sharing a common wall and blood supply with the ileum on the mesenteric side. We exteriorized the duplication cyst with normal ileum from the umbilical incision, and performed resection of the segment of the small bowel including the cystic mass. Histopathology revealed that the ileal duplication cyst was lined with gastric epithelium. The postoperative course was uneventful.