Colocolic intussusception caused by a descending colon lipoma in an adult: a rare case report.

Introduction: Adult intussusception is an uncommon clinical condition, accounting for only 5% of all intussusception cases and typically involving an identifiable pathological lead point, most often a neoplasm. Colocolic intussusception caused by a benign lipoma of the descending colon is exceptionally rare. Case presentation: A 47-year-old male presented with a 10-day history of intermittent periumbilical abdominal pain, loose stools, and fresh rectal bleeding. Imaging revealed a colocolic intussusception with a 5 × 4 cm fat-density lesion in the descending colon, suggestive of a submucosal lipoma. Exploratory laparotomy confirmed transverse-to-descending colonic intussusception with a lipoma serving as the lead point. Left hemicolectomy with side-to-side colocolic anastomosis was performed. Histopathology confirmed a benign submucosal lipoma. Discussion: Unlike pediatric cases, adult intussusception is usually secondary to an organic lesion. Lipomas are rare benign tumors, and those in the descending colon causing colocolic intussusception are especially unusual. Diagnosis often requires imaging, with CT scans being the gold standard. Surgical resection is the definitive treatment due to the high likelihood of pathology and risk of complications. Key clinical message: Colocolic intussusception due to descending colon lipoma is a rare but important differential in adults presenting with nonspecific abdominal symptoms and rectal bleeding. Timely imaging and surgical intervention are crucial for optimal outcomes. Conclusion: This case highlights the importance of maintaining high clinical suspicion and utilizing imaging in adults with vague gastrointestinal symptoms. Prompt surgical management of lipoma-induced intussusception can prevent severe complications.