EP600 - Colo-colonic Intussusception Caused by a Giant Pedunculated Sigmoid Lipoma Mimicking Malignancy

Purpose/Background: Adult intussusception is an uncommon clinical condition, accounting for less than 5% of all intussusception cases and up to 3% of intestinal obstructions. Approximately 60% of colonic intussusceptions in adults are associated with malignant etiologies.

Colonic lipomas are benign, non-epithelial adipose tumors most commonly found in the right colon. They are usually asymptomatic and discovered incidentally during colonoscopy or imaging; however, large lesions may present with features mimicking colorectal carcinoma or cause intussusception.

Methods/Interventions: A 43-year-old man presented with a one-month history of intermittent left lower abdominal pain, altered bowel habits, rectal bleeding, anorexia, and weight loss. Physical examination was unremarkable. Contrast-enhanced CT of the abdomen and pelvis demonstrated a target sign in the sigmoid colon, consistent with colo-colonic intussusception, with a lipomatous leading point. Colonoscopy revealed a large, ulcerated, partially obstructing pedunculated polyp, raising concern for malignancy.

Results/Outcomes: Given the risk of malignancy and partial obstruction, the patient underwent elective laparoscopic sigmoidectomy. The procedure was completed successfully without intraoperative complications. Histopathological examination of the resected specimen confirmed a pedunculated submucosal colonic lipoma with surface ulceration, and no evidence of malignancy.

The patient had an uneventful postoperative recovery and was discharged home on postoperative day three. At follow-up, he remained asymptomatic with resolution of abdominal pain and normalization of bowel habits.

Conclusion/Discussion: Colo-colonic intussusception secondary to colonic lipoma is a rare entity, with clinical presentation dependent on lesion size and location. Preoperative diagnosis can be challenging due to nonspecific signs and imaging findings. CT remains the imaging modality of choice for evaluating colonic lipomas, while colonoscopy allows direct visualization and tissue diagnosis. Surgical resection with appropriate margins remains the definitive treatment, offering excellent prognosis. Colonic lipoma should be considered in the differential diagnosis of adult colonic intussusception.