Small intestinal intussusception secondary to a submucosal lipoma.

Abstract

A woman with a medical history of mastectomy, thyroidectomy, and Hodgkin disease 10 years ago complained of intermittent abdominal pain for 9 to 12 months. Two days before admission, she had worsening of the pain and diminished bowel movements. Abdominal computed tomographic (CT) scan revealed a small bowel intussusception in the lower midabdomen (Figure 1, arrow). There was moderate small intestinal distention. The loops within the intussusception were thickened and presumed to be edematous. The origin of the intussusception was uncertain. The patient underwent an exploratory laparotomy and small bowel resection. The specimen consisted of a small intestinal segment with the intussusceptum telescoping into the intussuscipiens. Mucosa was edematous and hemorrhagic. The leading point was a polypoid mass, which measured 3.5 3 2.0 3 2.0 cm. The mass was firm and rubbery without ulceration. Cut surface revealed a yellowish, solid, homogeneous submucosal nodule (Figure 2), which microscopically was confirmed to be a lipoma. Intussusception is defined as the telescoping of a proximal segment of intestine, termed intussusceptum, into the distal intestinal loop, known as intussuscipiens.1,2 Intussusceptions may be enteroenteric, ileocolic, or colocolic.2 Although intussusception is a common cause of surgical emergencies in infants and children, it occurs relatively rarely in adults. A mechanical cause of intussusception is found in 90% of adults, but can be rarely demonstrated in infancy and early childhood.1 Known causes of intussusception in infants and children include lymphoma, lymphoid polyp, Meckel diverticulum, ectopic pancreas, acute appendicitis, leiomyoma, juvenile polyp, polyposis, enterogenous cyst, and duplication cyst. In 88% of infants and children, no definite cause for intussusception is found.1 Other possible causes include enlarged Peyer patches, viral infections, and trauma. Most cases of intussusception in adults are tumor related, with lipoma as the most common tumor. Other neoplasms include intestinal polyp, adenocarcinoma, leiomyoma, metastatic carcinoma, lymphoma, leiomyosarcoma, and melanoma.1,2 Additional causes include Meckel diverticulum, nonspecific ulcer, and ectopic pancreatic tissue.1