Adult ileoileal intussusception induced by an ileal lipoma diagnosed preoperatively: report of a case and review of the literature.

We herein report a case of adult ileoileal intussusception induced by an ileal lipoma. A 68-year-old woman with a history of small intestinal tumors was admitted to our hospital with severe, colicky lower abdominal pain, similar to episodes experienced in the past. A barium meal enema at the initial admission demonstrated a small intestinal tumor in the ileum 30 cm proximal to the ileocecal valve. Abdominal ultrasound sonography and computed tomography showed a sausage-shaped mass presenting as a target sign in the right lower abdomen, suggestive of intussusception. There was also a round mass of fat attenuation representing a lipoma, which was considered the lead point of the intussusception. The patient underwent emergency surgery and partial resection of the ileum, including the ileal tumor, following reduction of the intussusception. The resected specimen contained a round tumor measuring 1.5 × 1.5 × 1.4 cm, which was diagnosed histopathologically as an intestinal lipoma. The patient made a satisfactory recovery and was discharged on postoperative day 10. The clinical characteristics of previously reported lipomas with intussusception are also discussed, including the relationships between the tumor size and symptoms or location.