[Differential diagnosis of acute appendicitis and ileus. Invagination due to polypoid heterotopic gastric mucosa in the ileum without Meckel diverticulum].

A 13-year-old female presented with recurrent, right-sided abdominal pain since the age of 2 years. Examination showed a tender, cylindric mass in the right lower quadrant. Ultrasound and MRI revealed an ileocolic intussusception. On laparotomy, there was an ileo-ileal intussusception due to a 3.8-cm polypoid tumor about 40 cm proximal to the ileocoecal valve. Histology showed polypoid heterotopic gastric mucosa with no Meckel's diverticulum. To our knowledge, only 12 cases of intussusception of heterotopic gastric mucosa in the ileum without Meckel's diverticulum have been reported in literature. This case adds to this small list and represents a possible cause of intussusception.