Adult ileocolic intussusception due to a terminal ileal lipoma mimicking malignancy: a rare case report.

Introduction and importance: Adult ileocolic intussusception due to a terminal ileal lipoma is rare but clinically significant. The value of this case lies in how a typically benign and well-characterized condition presented with malignant-like clinical, radiologic, and inflammatory features, necessitating atypically extensive operative management and emphasizing diagnostic vigilance when assessing adult ileocolic intussusception. Case presentation: We report the case of a 61-year-old male who presented with signs of subacute intestinal obstruction due to ileocolic intussusception secondary to a terminal ileal lipoma. Imaging via contrast-enhanced CT scan demonstrated an ileocolic intussusception with a well-defined, fat-density mass in the terminal ileum, indicating a benign submucosal lipoma serving as the lead point. This finding enabled an accurate preoperative diagnosis and facilitated surgical planning. An extended right hemicolectomy with primary anastomosis was performed, and histopathology confirmed a benign submucosal lipoma. Clinical discussion: Adult intussusception is rare and usually caused by a pathological lead point, most often a benign tumor such as a lipoma. Unlike pediatric cases, symptoms in adults are typically nonspecific and may mimic subacute or chronic bowel obstruction. Contrast-enhanced CT is the most sensitive tool for identifying the intussusception and its cause, allowing preoperative planning. Surgical resection remains the standard of care due to the high likelihood of an underlying lesion and the risk of ischemia or malignancy. Conclusion: This case emphasizes the unique clinical presentation and diagnostic complexity that differentiate benign lipoma-induced intussusceptions from typical cases. The lesion's extension up to the right colic flexure required an extended right hemicolectomy, underscoring the importance of individualized management.