Ileocolic Intussusception in Infancy is not Always Idiopathic - Adenomyoma as the Leading Point

BACKGROUND Intussusception is a frequent abdominal emergency in infancy, requiring immediate diagnosis and therapeutic intervention. In approximately 90% of cases, intussusception seems to be idiopathic. There has been a reported association of intussusception with lymphoid hyperplasia of Peyer patches in the terminal ileum, possibly acting as the triggering factor. Clinical presentation varies substantially, while the etiology seems idiopathic in most reported cases. CASE REPORT This case describes a previously healthy 2-month-old girl who presented with an episode of non-bilious vomiting and deterioration during the 12 hours preceding the visit. Abdominal ultrasonography revealed the typical target sign in the right iliac fossa, without visible peristalsis, confirming the diagnosis of intussusception. Failure of non-surgical reduction led to emergency laparotomy with the working diagnosis of intussusception due to Meckel's diverticulum. However, laparotomy instead revealed an adenomyoma of the small intestine, a rare benign tumor-like lesion, as the pathological lead point. CONCLUSIONS This case is interesting for 2 distinct reasons. Not only does it underline the need to maintain a high index of suspicion for triggering factors, even in patients within atypically affected age groups, but it also adds to the remarkably limited selection of reported adenomyomas of the small intestine acting as the pathological lead point for intussusception. In this case report, we aspire to emphasize that especially in patients outside the most affected age group, pediatric surgeons should remain aware of the possibility of adenomyoma as a pathological lead point.