Duodenoduodenal intussusception: Report of three challenging cases with literature review.

Small bowel intussusception is an uncommon condition with cases of duodenoduodenal intussusception (DDI) being exceptionally rare. Adult intussusception occurs infrequently and differs from childhood intussusception in its presentation, etiology, and treatment. DDI is very unusual due to the fixed position of the duodenum within the retroperitoneum. The lead point usually is hamartomatous polyp, adenoma, or adenocarcinoma. Only few cases of DDI in adults have been reported in the literature. We herein report a series of three cases of DDI encountered in a tertiary level research institute. All cases had underlying abnormality acting as lead point with different etiologies. DDI is a challenging condition due to its rarity and nonspecific presentation and should be considered in the differential diagnosis of gastric outlet obstruction, pancreatitis, and obstructive jaundice. We elaborate this condition with a detailed review of the literature to gain a better understanding of its clinical features and enable early diagnosis.