Adult Ileo-ileal Intussusception Induced by a Large Lipoma

Introduction: Abdominal pain secondary to intussusception is an uncommon presentation of abdominal pain in the emergency department. Intussusception is defined as the prolapse of proximal segment of the intestine into the distal segment. Patients present with colicky abdominal pain that is localized to one portion of the abdomen with accompanying nausea and vomiting. In adult patients, the underlying cause is usually a structural lesion, in this case a large ileal lipoma. Medical intervention is required because such lesions can have malignant etiology. We present a case of a small bowel intussusception secondary to a large gastrointestinal lipoma. Case description/methods: A 43-year-old woman was admitted to the emergency department with progressively worsening, acute colicky abdominal pain of 3 week duration. Her pain was localized to the right lower quadrant of the abdomen and did not respond to analgesia and antispasmodic medications. On admission the patient was afebrile, hemodynamically stable with a blood pressure of 126/68 mmHg and with a regular pulse of 86/min. Upon clinical evaluation of the abdomen, there were no peritoneal signs. Laboratory investigations showed an elevated white blood cell count of 12,000/μl. Computed tomography (CT) scan of the abdomen with oral and intravenous (IV) contrast showed a ileo-ileal bowel intussusception with a intraluminal soft tissue mass with negative attenuation consistent with a lipoma. Based on this imaging finding, a colonoscopy was completed which showed a large partially obstructing nonbleeding malignant appearing mass proximal to the ileocecal valve (Figure 1). Colorectal surgery was consulted, a laparoscopic exploration with resection of the 2 × 3 cm lipoma and a resection of 5 cm of small bowel was performed with end to end anastomosis. Histological analysis of the mass showed an ulcerated lipoma without evidence of malignancy. The postsurgical hospital course was uneventful and the patient was discharged days later. Discussion: Intussusception in adult patients, a rare occurrence accounting for only 5-10% of all reported cases. In an ileo-ileal intussusception, a lipoma is often the lead point which is responsible for telescoping a portion of the ileum causing lymphatic and venous congestion resulting in intestinal edema. A lipoma on CT imaging presents as a characteristic fatty densitometric area with smooth margins. This case highlights the importance of considering a gastrointestinal lipoma as a rare cause of intussusception in adult patients.Figure 1.: Endoscopic picture showing a malignant mass in the third part of duodenum. Figure 2: Endoscopic picture showing a malignant mass in the colon hepatic flexure. Figure 3: High power view showing normal colon glands and malignant lymphocytes Figure 4: CD20+ B-cells Figure 5: CD79a + B-cells Figure 6: Ki-67; High Proliferative Index consistent with high grade lymphoma.