Case report

A 73-year-old woman with a 3- to 4-month history of periumbilical discomfort was transferred from a regional hospital due to severe generalized abdominal pain and vomiting which occurred 8 hours prior to this presentation. There was no remarkable medical or family history. Her history revealed no chill, fever, generalized weakness, weight loss, chest pain or dyspnea. Abdominal pain persisted around the umbilicus without radiation and was not aggravated by changes in position. Vomiting occurred 3 to 4 times a day, but diarrhea, melena or hematochezia did not occur. Three hours prior to this presentation, she had normal defecation. She had no hematuria, frequency, dysuria or residual urine sense.

Her vital signs were as follows: blood pressure, 150/90 mmHg; pulse rate, 84 beats/min; respiratory rate, 20 beats/min; and body temperature, 36.5ºC. On physical examination, she showed pale conjunctiva, clean breath sounds and normal heart sounds, but did not show wheezing, rales or murmur. Her abdomen was mildly distended, and bowel sounds were decreased. Abdominal palpation showed minimal tenderness on periumbilical area and left upper abdomen. A 10-cm mobile mass was palpable at the site of maximal tenderness. There was no rebound tenderness. Digital rectal examination revealed neither melena, hematochezia, nor mass. Percussion of the costovertebral area showed no tenderness.

Blood tests revealed: WBC, 12,850/mm ³ (neutrophil, 90.1%); hemoglobin, 10.4 g/dl; platelet, 311,000/mm ³ ; BUN/Cr, 10/0.9 mg/dl; AST/ALT, 28/23 IU/L; amylase, 44 IU/L; total bilirubin/direct hilirubin, 0.5/0.1 mg/dl; total protein/albumin, 6.7/3.6 gldl; alkaline phosphatase (ALP) 45 IU/L; and PT/aPTT, 10.7/27.0 sec. Arterial blood gas analysis showed: pH, 7.426; pCO₂, 33.8 mmHg; P0₂, 66.3 mmHg; HCO₃, 23.0 mmol/L; base excess, -1.9 mmol/L; and Sa0₂, 92.5%. Plain radiographs of the abdomen exhibited findings of small bowel ileus and an air-fluid level suggestive of intestinal obstruction. Computed tomography (CT) of the abdomen was performed in order to rule out colon cancer, intestinal obstruction, diverticulitis and omental infarction. CT scan of the abdomen revealed an ileoileal intussusception without any evidence of bowel strangulation but with a low-density mass suggestive of a lipoma (Figure 1). Emergency operation was performed for radical treatment. At surgery, the 110-cm ileum was telescoped into the approximately 170-cm proximal segment. A 4x4-cm hard mass was manually dissected from its originating site, and the ileum was transected proximally and distally 5 cm beyond the mass, encompassing the mass after the viability of the ileum was confirmed to be intact. Histopathological examination of the surgical specimen revealed a lipoma of the ileum. After surgery, she improved and there were no significant complications such as wound infection.

Figure 1

Figure 1: Enhanced abdomen CT scans. White arrow indicates a low density mass within the intussusceptum, which is the etiology of ileoileal intussusception.

Discussion

Intussusception occurs when one segment of the intestine (intussusceptum), constricted by a wave of peristalsis, suddenly becomes telescoped into the immediately distal segment of bowel (intussuscipiens). It can cause intestinal obstruction or strangulation. In more than 90% of pediatric patients, there is usually no underlying anatomic lesion or defect in the bowel and the patient is otherwise healthy, but it has been suggested that intussusception may be induced by enlarged nodes associated with adenoviral infections ₄ . Approximately 80% of pediatric patients with intussusception can be successfully treated with pneumatic or hydrostatic reduction, whereas most adult patients with intussusception require surgical treatment ₃ . Benign polyps, lipomas, the appendix, Meckel's direvticulum and malignant tumors, such as lymphomas, gastrointestinal stromal tumors and primary or metastatic adenocarcinomas may serve as causative lead points for adult intussusception ₃ . The site of intussusception differs according to the underlying lesions. In 69% of colocolonic intussusception, neoplasms were detected as causative lead points, of which 70% were malignant tumors; in 57% of small bowel intrssusception, neoplasms were detected, of which 30% were malignant tumors ₅ .

Adult intussusception may manifest itself as acute, intermittent or chronic symptoms ₆ . Chang et al reported that 46% of patients presented with acute symptoms that they experienced over a period of less than 3 days, while the remaining patients presented with subacute to chronic symptoms lasting 7 to 90 days ₃ . The most common symptom was abdominal pain and other symptoms differed according to the site and degree of obstruction: nausea and vomiting developed in 60% of patients with enteric intussusception and in 42% of patients with colonic intussusception, and bloody stool was observed in 4% of patients with enteric intussusception and in 33% of patients with colonic intussusception ₃ . Azar and Berger reported that 7% of all patients with adult intussusception had a palpable abdominal mass ₆ .

Available diagnostic modalities include plain radiography, abdominal ultrasonography, abdominal CT, barium studies, angiography and nucleotide studies. Abdominal CT has been reported to be the most accurate diagnostic tool ₂,₃,₆ . Significant findings of abdominal CT comprise a mass lesion (thickened segment of the bowel), a crescent-like, eccentric low-attenuation fatty mass (entrapped mesenteric fat), a rim of contrast material encircling the intussusceptum (coating of the opposing bowel wall of the intussusceptum and intussuscepiens), air bubbles peripheral to the upper part of the intussusception and a leading mass ₇ .

Although the standard treatment of adult intussusception has not yet been established, surgical resection of the intussusception without reduction is the preferred method except for the cases caused by postoperative adhesion because adult intussusception is frequently associated with malignancy or chronic inflammation ₂,₆,₇ . However, the cases that occur at the duodenum or rectum and those that are caused by benign lesions can be successfully treated with segmental intestinal resection after reduction, avoiding unnecessary en-block resection ₇ .

Conclusion

Since most patients with adult intussusception present with nonspecific symptoms or with a variety of acute, subacute and chronic symptoms, adult intussusception should be considered as a cause of acute abdomen in emergency department.

Correspondence to

Je Hyeok Oh, M.D., Department of Emergency Medicine, Chung-Ang University Hospital, 224-1 Heukseok-dong, Dongjak-gu, Seoul 156-755, Republic of Korea, Tel/Fax: +82 2 6299 1347, E-mail address: ojh7178@caumc.or.kr