Mesenteric heterotopic pancreas in a pediatric patient: A case report and review of literature

Figure 4 Schematic diagram of the “misplacement theory”. A, B: The pancreas develops from the ventral and dorsal pancreatic buds, which develop at the junction of the foregut and midgut during the 4^th week of gestation; C: As the foregut elongates, the developing ventral pancreas, gallbladder, and bile duct rotate clockwise posterior to the duodenum and join the dorsal pancreas in the retroperitoneum. The ventral pancreatic bud rotates clockwise and fuses with the dorsal bud at the 7^th week of gestation; D: According to the misplacement theory, deposits of pancreatic tissue are “dropped” into the developing gastrointestinal system during rotation of the foregut when fragments of pancreas become separated and develop into mature elements. Yellow points in D indicate possible locations of heterotopic pancreas. F: Foregut; M: Midgut; VPB: Ventral pancreatic bud; DPB: Dorsal pancreatic bud; LB: Liver bud; S: Stomach; D: Duodenum; P: Pancreas; L: Liver; J: Jejunum.