Tumor and Tumor-Like Lesions of the Pediatric Retroperitoneum

Abstract

The retroperitoneal space literally means the (potential) space behind the parietal peritoneum of the abdominal cavity. It has no distinct borders; also, structures that lie between the parietal peritoneum and abdominal wall can be classified as retroperitoneal, at the ventral side sometimes referred to as properitoneal. It extends from the pelvic brim to the diaphragm. Embryologically, some organs have a retroperitoneal origin: adrenal glands, kidneys, ureters, bladder, aorta, inferior caval vein, and part of the rectum (primary retroperitoneal). Some organs were originally suspended in the abdominal cavity by a mesentery but migrated into a retroperitoneal position: head and body of the pancreas, duodenum, ascending and descending colon (secondary retroperitoneal) (Table 1).