Stool filling of an intestinal duplication cyst at the ileocecal valve triggers colonic intussusception: a case report

BACKGROUND: Intestinal duplication, a congenital malformation, is considered a rare condition, particularly in adults. Although it affects young children, a minority of patients remains asymptomatic until adulthood. Here, we describe a case of an intestinal duplication cyst that caused intussusception by a unique mechanism. CASE PRESENTATION: A 19-year-old man was admitted to our hospital for intermittent abdominal pain. Computed tomography revealed colonic intussusception induced by a nodular mass in the ileocecal region. Urgent ileocecal resection was performed because of the risk of colonic ischemia. The resected material comprised a stool-filled noncommunicating cyst that protruded into the enteric lumen at the ileocecal valve. Histological analyses revealed that the inner wall of the cyst was lined with colonic mucosa and that the muscle layer of the cyst was shared with that of the original enteric wall; furthermore, the cyst had a vestige of an opening site in the wall. We concluded that the cyst was an intestinal duplication that poured stool into its lumen through the tiny orifice, thereby triggering intussusception. CONCLUSIONS: The present case suggests that stool-pouring can cause intussusception into the space of an intestinal duplication lesion.