Gastrointestinal: Gastrogastric intussusception

Intussusception is defined as the invagination of one part of the gastrointestinal tract into another. This almost always involves invagination of a proximal segment of bowel (intussusceptum) into an adjacent distal segment (intussuscipiens). Intussusception can be restricted to either the small bowel or the large bowel or may involve both the small and large bowel. The development of intussusception almost always results in a partial or complete bowel obstruction and may result in intestinal ischemia or infarction. The disorder is much more frequent in children (90%) than in adults. Furthermore, only approximately 5% of children have a clearly defined cause for intussusception such as a polyp or a Meckel's diverticulum. In contrast, at least 90% of adults have an anatomical abnormality, usually a benign or malignant neoplasm. In children, the typical site for intussusception is ileocolic (80%) but in adults, the majority are either ileo-ileal or colocolic. In the proximal gastrointestinal tract, intussusception is rare but there are case reports of gastroduodenal intussusception associated with gastric polyps and intussusception at the site of a gastrojejunostomy. In the case outlined below, gastrogastric intussusception occurred because of a stromal cell tumor in the upper stomach. As far as we are aware, there is only one previous case in the English literature. An 83-year-old woman was admitted to hospital with a 3-month history of melena and weight loss. Blood tests revealed a severe iron deficiency anemia with a hemoglobin of 6.3 g/dL (63 g/l). A computed tomography scan of the abdomen revealed a gastrogastric intussusception that seemed likely to be secondary to a mass in the gastric cardia. In the axial image in Figure 1, the mass formed the high-density center that was surrounded by the swollen wall of the intussusceptum (arrow), the low-density layer of mesogastric fat (arrowhead) and the distal gastric wall (intussuscipiens). In another image (Figure 2), mesogastric fat and blood vessels were drawn into the intussusception (arrow). At endoscopy, there was a mass, 5 cm in diameter, in the upper stomach with active bleeding from the mucosal surface. This was confirmed at laparotomy and she was treated with a local gastric resection. Histological evaluation revealed a gastrointestinal stromal tumor.