A Case of Spontaneously Reduced Ileoileal Intussusception Caused by a Lipoma.

Intussusception in adulthood is unusual. We describe herein a rare case of adult ileoileal intussusception caused by an ileal lipoma, which was diagnosed preoperatively and was confirmed at the operation to have reduced spontaneously. A 68-year-old woman experienced sudden-onset colicky pain in the upper abdomen accompanied by vomiting and was brought to our hospital by ambulance. Physical examination revealed a distended abdomen and tenderness in the upper abdomen. Laboratory findings showed slightly elevated inflammatory parameters. Abdominal computed tomography (CT) showed a target sign in the ileum, which is a typical sign of intussusception. Additional caudal-side scans showed a homogenous and fatty mass measuring 2.5 cm that was considered to be the leading point for the invagination. These findings led to a pre-operative diagnosis of intussusception induced by a lipoma. The patient underwent emergency surgery. Laparotomy revealed a yellowish, soft ileal tumor measuring 2.5 cm in diameter and that the intussusception had already been reduced at laparotomy. Approximately 15 cm of the ileum's length, including the tumor, was resected, and an end-to-end anastomosis was performed. Adult intussusception caused by an ileal lipoma is a rare condition. However, CT is the most useful tool for making a definite preoperative diagnosis based on its typical findings.