Adult Ileo-Ileal Intussusception Secondary to a 9 cm Pedunculated Submucosal Lipoma: Clinical, Radiologic, and Pathologic Correlation.

Adult intussusception is a rare clinical entity and is typically associated with an underlying structural lesion, in contrast to pediatric cases where idiopathic causes predominate. We report a case of ileo-ileal intussusception in a 21-year-old male secondary to a large pedunculated submucosal lipoma. The patient presented with recurrent episodes of abdominal pain initially attributed to ileitis. Sequential computed tomography (CT) scans demonstrated a persistent ileo-ileal intussusception and identified a fat-density intramural lesion, allowing preoperative suspicion of a submucosal lipoma as the lead point. Urgent exploratory laparotomy revealed a long-segment ileo-ileal intussusception caused by a large pedunculated intraluminal mass. Manual reduction was performed, followed by segmental small-bowel resection and a stapled anastomosis. Histopathologic examination confirmed a 9 cm submucosal lipoma composed of mature adipose tissue, without evidence of ischemia or malignancy. The postoperative course was uneventful. This case highlights the diagnostic value of CT imaging in identifying fat-containing lead points and illustrates the radiologic, surgical, and pathologic correlation characteristic of lipoma-induced intussusception in young adults.